3. A 34-year-old CKD5 female patient on HD due to unknown kidney disease. She received a kidney offer from her cousin. 111 mismatch with DSA (A1 with MFI 1000). Her blood pressure is well controlled. She gives a history of DVT for which she was treated by warfarin for 6 months. She had 2 successful pregnancies and one miscarriage. No other significant medical history.
- Do you think the management was appropriate?
- How do you manage this case?
- What is meant by the MFI?
- What is the difference between PRA and cPRA?
The management of this patient does not seem adequate, as she may have an uninvestigated autoimmune disease (history of thrombosis and miscarriage).
Before proceeding with the transplant listing I would try to clarify the reason for the kidney failure with a biopsy, as the risk of autoimmune disease exists. A kidney biopsy could help clarify the case.
In the operative period, with the use of warfarin, I would try to use the heparin bridge. The ideal would also be to investigate thrombophilia, but with the use of warfarin, this investigation is compromised.
MFI is a semi-quantitative method to measure the immunofluorescence intensity of an immunoassay where polystyrene spheres impregnated with different proportions of two fluorescent dyes that will react with specific HLA antibodies are used in a microtiter plate.
In PRA, the cell panel that is used for allosensitization analysis uses samples from that transplant center, which can generate different percentages according to each center.
In the cPRA, a virtual panel is used that is representative of the entire registered population.
Female Patient with history of thrombophilia with previous DVT and abortion
so thrombophilia screen is needed:
protein C , S
Factor Leiden V mutation
Anti-thrombin III levels
Anti-phospholipids antibodies
MTHFR (Methylenetetrahydrofolate reductase ) mutations
Plan for early anticoagulation post kidney transplantation
Presence of DSA (2 cross matches ( one CDC and another folwcytometry cross match )
if negative so kidney transplantation with ATG induction and use of steroids , MMF and Prograf as a maintenance therapy
What is the difference between PRA and cPRA?
Panel reactive Antibody (PRA) detects preformed recipient antibodies in the serum using a panel of Lymphocytes from a panel of 100 blood donor and give apercentage of reaction between antiobodies in the patients serum and the lymphocytes cells
cPRA : done by computer algorithm to detect unacceptable antigens based on available donor pool antigens
MFI , mean fluriscent intensity :
Define intensity of antibody react with panel of donor lymphocytes using the flowcytometry
Do you think the management was appropriate?
This patient has following issues:
34 year old ESKD patient on Hdx , bad obstetric history due to miscarriages and a history of DVT on warfarin and a properly controlled BP , offered a Donor kidney with 111 mismatch with A1 MFI 1000
I think the management plan was not enough, as a patient with recurrent miscarriages should be properly investigated for hypercoagulable states especially lupus and Antiphospholipid syndrome.
How do you manage this case?
Assessment of this patient to check for the possibility of SLE and or Antiphospholipid syndrome include full history including skin rash , joint pains , hematological or neurological symptoms, followed by immunological profile for lupus as well as Antiphospholipid antibodies ( lupus anti coagulant , anti-cardiolipin antibodies and anti-beta2-GP I antibodies )
IfAntiphospholipid syndrome was confirmed , the patient will require lifelong warfarin with INR 2-3
Yet still can proceed for Tx . With bridging with LMWH perioperatively.
Regarding immunosuppression ; this is a highly sensitized pt who will require induction with basiliximab as well as triple immunosuppression post Tx .
What is meant by the MFI?
Is the level of HLA antibodies detected by solid immunoassays , it is a semi-quantitative assay
What is the difference between PRA and cPRA?
The patient has a history of DVT and miscarriage and should be evaluated for thrombophilia, homocysteine levels, and anti-phospholipid antibodies. In the event of a positive result, she must be started on warfarin. Warfarin should be stopped five days before surgery, and the INR should be below 1.5 to proceed with the transplant. After 12 to 24 hours of surgery with good graft function, she should be started on LMWH (1 mg/kg) and continued until no further invasive procedure, such as a biopsy or re-exploration, is anticipated. After that, switch to warfarin.
She also has positive class 1 donor-specific antibodies (MFI 1000), which is considered low-level sensitization (less than 2000). CDC and flow cytometry cross-matching, if negative, will require ATG induction and can proceed with transplant with slightly higher chances of ABMR than usual, but graft outcomes are not much different from non-sensitized transplants.
MFI:
Solid-phase immunoassays that use luminex can measure both the specificities of HLA antibodies and the levels of antibodies as measured by mean fluroscence intensity (MFI). The immunological risk assessment is based on providing MFI information for each defined antibody specifities that is greater than a certain MFI threshold. MFI of greater than or equal to 1000 is considered significant. Class 1 more than 2000 to 3000 and class 2 more than 4000 to 5000 is considered high level of sensitization and considered as a contraindication for transplant with that donor.
PRA and cPRA:
PRA is a cell-based test that compares a patient’s serum to a panel of lymphocytes from a local blood donor pool. It is calculated as the percentage of donors with whom the recipient has positive antibodies. A PRA of 80% means that the recipient has a 20% chance of finding a compatible donor. Despite its ease of use, PRA, being cell-based, is relatively insensitive and non-specific. In 2000, testing with a single antigen bead made it possible to put cPRA values into the allocation system. Calculated PRA is based on single antigen bead assay which is more specific and utilize know HLA frequencies in local donor pool
1.The patient has CKD on regular hamodialysis, she gives history of DVT and she is warfarin therapy, Also she has history of abortion, she should be investigated to detect any underlying hyper-coagulability state ( CBC,peripheral blood smear,PT,aPTT, fibrinogen,protein C and protein S, Antithrombin , PCR for factor V leiden, antiphosholipid antibodies and homocysteine level ).
2.How do you manage this case?
According to immunological risk , mismatch 111 is acceptable , there is DSA( A1MFI 1000) but this is below the significant MFI as cutoff for MHC class I is 2000.
A study compared kidney transplant outcomes in three group, first group had negative DSA ( MFI < 100), second one had low level DSA (MFI 100 to 1000) , third group with positive DSA ( MFI > 1000), the study showed that the rate of antibody mediated rejection was the highest in the third group with positive DSA(10.3%) followed by the second group with low level DSA(7.8%) followed by the first group(4.5%), although the patient and graft survival are comparable between three groups after a follow up for 2.4+/-1.26 years.
According to history of hypertension
need to follow after transplantation as may become worse after transplantation due to immunosuppressive therapy ( MMF or steroid).
the patient need cardiac evaluation as it may lead to LVH, also HTN is independent risk factor for heart failure,cerebrovascular evaluation.
According to history of DVT
search for the cause , also need to be investigated to ensure re-canalization (Duplex US, contrast venography).
3.MFI : the main intensity of antibody expression on flow cytometry,it is a semi-quantitative measure for antibody level, had different cutoff.The higher MFI,the higher risk of rejection.
4.PRA:is a tool for assessment of degree of desensitization to HLA antibodies,was determined by the reactivity of the patient s from serum against panels of cells (transplant donor pool)
calculated PRA : uses the results of single antigen bead assay to identify the specifity of anti-HLA antibodies, in combination with the known frequencies of HLA antigens within the donor population.
Young lady with DVT history and no obvious trigger not clearly provoked by risk factor but has history of miscarriage: all this mandate detailed workup for hypercoagulable state, investigation should include:
Ø Bleeding profile
Ø ANA profile
Ø Lupus anticoagulant
Ø Antiphospholipid antibodies
Ø Anticardiolipin antibody,
Ø Activated protein c (APC) resistance
Ø Antithrombin III
Ø Factor v and prothrombin gene mutations
Ø Protein C and S
Ø And homocystine levels
Median Fluorescence Intensity, semi quantitative method used to indicate antibody levels that form an important function in informing a pre transplant immunologic
risk assessment. The cut-off levels are variable in different laboratories; however, the typical cut-off levels of 2000 for class I DSAs and 5000 for class II DSAs.
PRA: Patient serum is tested against lymphocyte panels obtained from volunteer blood donors that can either be “random” or alternatively “selected” to represent the HLA types in the potential organ donor population (termed panel reactive antibodies; PRA).
cPRA: Calculated panel reactive antibodies are used synonymously to describe the level of allosensitization, where 0% cRF is nonsensitized, 50% cRF is antibody incompatible with half of a random donor pool, and 90% cRF would be antibody incompatible with 9 out of 10 random donors.
Kidney transplant is the best renal replacement therapy for end-stage renal disease patients. it is associated with better morbidity, mortality, and quality of life.
Regarding recipient evaluation:
She will need (cardiac, pulmonology, vascular, hematological, immunological, gastroenterology, infection, malignancy, and urological) evaluation.
As noticed from her history
Vascular evaluation: practice varies among transplant centers. some transplant centers routinely ask only for an aortoiliac Doppler ultrasound and calculate the ankle-brachial index (ABI), while others screen first with a non-contrast CT of the abdomen/pelvis to assess iliac calcification and a follow-up Doppler ultrasound if there are concerns about flow. Furthermore, recent data suggest that computed tomography angiography (CTA) and magnetic resonance angiography (MRA) become the most sensitive and informative methods for the PAD assessment (25-30). Arteriography is still considered the gold standard for diagnostic evaluation of PAD which still remains necessary but in selected cases 31,32. this patient had a history of DVT which should be evaluated properly by CT angiography with contrast on abdominal pelvic and lower limb vessels or MRA after referral to vascular
Immunological risk:
· ABO system: not mentioned
· HLA mismatch: 111 mismatches
· DSA: 1000 MFI against A1
· Regarding Wet Crossmatch: including complement-dependent cytotoxicity crossmatch (CDCXM) and flowcytometry crossmatch (FCXM) we don’t have results but most probably to be negative in such low MFI. MFI is a measuring unit that gives a quantitive evaluation of antibodies (DSA) in the degree of fluorescence dye. MFI-positive cutoffs ranging from values 1000 to 1500 yielded a high level of agreement (>90 percent) among HLA laboratories in determining the presence or absence of an HLA antibody. DSAs with low MFI or Historical DSA is difficult to predict whether this will alter graft outcome as there are no assays to evaluate the latent cellular memory response or determine that this low-titer of DSA will remain low and it will not rapidly increase post-transplantation after re-exposure to the same antigen. also, MFI is not correlated with antibody concentration, titer and strength, and concentration. MFI levels have negative predictive value, but they are unable to predict a positive crossmatch. the standard SAB assay detects all IgG antibodies, irrespective of subclass and ability to complement fixation. The conclusion is maybe this DSA (even with this low MFI) is considered of great clinical value or with limited value.
Hematological evaluation:
She gives a history of DVT for which she was treated by warfarin for 6 months. She had 2 successful pregnancies and one miscarriage. This is maybe related to an underlying hypercoagulable state or antiphospholipid syndrome which needs to be evaluated before transplant.
PRA stands for Panel Reactive Antibodies: it’s a wet crossmatch in which a patient’s serum (antibodies) is mixed against lymphocytes (HLA of potential donors) obtained from a panel of about 100 blood donors.
PRA is not standard and difficult to interpret and may underestimate or overestimate the actual immunological risk of the patient. Results of antibodies against HLA class I and class II are expressed separately.
CPRA is a standardized test based on SAB in which a patient’s serum is virtually tested against 10000 potential donors giving results based on unacceptable antigens that the patient is most highly sensitized against them. It gives results against both HLA class I and class II which reflect the actual immunological status of the patient.
References
1. Tang GL, Chin J, Kibbe MR Advances in diagnostic imaging for peripheral arterial disease. Expert Rev CardiovascTher (2010) 8(10): 1447- 1455.
2. Owen AR, Roditi GH Peripheral arterial disease: the evolving role of non-invasive imaging. Postgrad Med J (2011) 87(1025): 189-198.
3. Bray R.A. The acceptability and application of virtual crossmatching in lieu of serologic crossmatching for transplantation. Virtual Crossmatch Work Group Report. Centers for Disease Control and Prevention. https://www.cdc.gov/cliac/docs/addenda/cliac1114/8_BRAY_Virtual_Crossmatch_Workgroup_ Report_Nov-2014.pdf Published 2014. Accessed April 1, 2022.
4. Morris A.B., Sullivan H.C., Krummey S.M., et al. Out with the old, in with the new: virtual versus physical crossmatching in the modern era. HLA. 2019;94:471–481. doi: .1111/tan.13693.
5. Chowdhry M., Agrawal S., Thakur Y., et al. Implication of a positive virtual crossmatch with negative flow crossmatch: a mind-boggler. Asian J Transfus Sci. 2020;14:79–82. doi: 10.4103/ajts.AJTS_159_18.
-Do you think the management was appropriate?
This patient should have been investigated for thrombophilia ; APL syndrome, SLE and autoimmune disease. Detailed history of DVT (provoked or unprovoked) and the miscarriage .Also, other possibility such as Idiopathic membranous GN or secondary to an underlying malignancy which of is associated with thrombotic events.
Multisystem approach including rheumatologist, hematologist and nephrologist and thrombophilia screen, coagulation and autoimmune screen.
Consideration of history of arterial thrombus which would support APLS .Radiological investigations to rule out other possible causes of thrombosis (arterial and venous) before transplantation (doppler US, MR Pelvis)
We should examine the patient for any rash, previous history of pericarditis, pleuritis, arthritis to diagnose SLE and related lab tests.
– MFI:
MFI is a semiquantitative analysis of the HLA antibodies in the plasma of transplant recipient. IFA is used to measure the fluorescence intensity of the anti-antibodies targeting the donor specific antibody
Difference between PRA and c PRA:
Panel reactive Antibody (PRA) detects preformed recipient antibodies (patient serum) using a panel of typing cells ;Lymphocyte from a panel of 100 blood donors and provide a percentage of cells that the serum reacts with.
c PRA gives an approximation of the patients candidate for transplantation. Calculation specific unacceptable antigens in the wide donor database
Reference
-Sullivan, HC, Liwski, RS, Bray, RA & Gebel, HM. The Road to HLA Antibody Evaluation: Do Not Rely on MFI. Am J Transplant 2017; 17: 1455– 1461. https://doi.org/10.1111/ajt.14229
-Review Am J Transplant
2010 Jan;10(1):26-9. doi: 10.1111/j.1600-6143.2009.02927.
· Q1: No, she should’ve had proper evaluation for thrombophilia for antiphospholipid antibodies, protein C and S deficiency, factor V Leiden, Prothrombin gene mutation and hematologist consultation about life-long anticoagulation medications. Since her miscarriage could’ve been due to thrombophilia.
· Q2: She needs complete thrombophilia workup. History and Ph.E to rule out autoimmune disorders such as SLE.
Lab tests: C3, C4, ANA, Anti-ds DNA, antiphospholipid Ab, anticardiolipin Ab, lupus anticoagulant, activated protein C, protein S, factor V Leiden, prothrombin gene mutation (G20210A), Homocysteine level and MTHFR mutation.
Cardiovascular and complete peripheral vascular evaluation are necessary. According to etiology of thrombophilia, appropriate anticoagulation especially heparin after TX and then switching to oral anticoagulation might be necessary. Induction with ATG or Alemtuzumab is necessary because of DSA.
· Q3: MFI means mean fluorescence that shows DSA strength. MFI higher than 2000 for class I anti-HLA Abs and more than 5000 for class II anti-HLA Abs refers to high titer DSA and high-risk TX.
· Q4: Penal reactive antibody (PRA) is performed by adding the recipient’s serum to a panel of WBC of defined population of donors (50 to 100 people).
after addition of complement, cell lysis percentage is determined which demonstrates the presence of anti-HLA Abs. In calculated PRA (cPRA), a larger pool of donors (about 10000 people) are used and the percentage of donors who are expected to have unacceptable antigens for a recipient is determined.
I think that this patient was not appropriately managed in view of the bad obstetric history (the miscarriage), and the DVT(provoked or unprovoked). She needs to be evaluated thoroughly with a detailed history and autoimmune workup especially for SLE and antiphospholipid antibody syndrome as this may be the primary cause of kidney disease which is not known. APS is highly suspected based on a combination of clinical criteria; vascular and adverse pregnancy-related outcomes, more specified antiphospholipid antibodies (aPL) on two or more occasions at least 12 weeks apart need to be present.
A multidiscipline approach with involvement of a rheumatologist and hematologist.
The gaps in the diagnosis and management of this patient that need to be fulfilled before we proceed to transplantation.
Beside the appropriate history and thorough physical examination we need to do investigations that include:
For SLE: ANA , anti DNA, C3 , C4
For antiphospholipid syndrome: antibodies to cardiolipin ,beta2-glycoprotein and lupus anticoagulant.
Thrombophilia screen: Protein C, Protein S, Antithrombin III, Factor V Leiden, Prothrombin gene mutation and Serum homocysteine level
If SLE is confirmed, she needs to be in remission for at least 6 months before proceeding to transplantation
IF APS is confirmed, lifelong anticoagulation with warfarin is required and bridging anticoagulation with LMWH in the perioperative period is required.
With regard to this offer (111 mismatch with DSA to A1 with MFI 1000) we will require a FXCM. A1 is a common antigen which is more in Europe but it is not only the MFI titer that increases rejection risks, the IgG subclass and ability to bind and activate the complement cascade is more important.
It is a semi quantitative measure of DSAs
It signifies the intensity of antibody expression on flow cytometry.
The higher the MFI, the greater the risk of rejection. The clinically significant MFI varies between labs from 1000-10000.
The Cut off MFI in Sheffield kidney institute for clinically significant MFI is 2000 for class I and 5000 for class I DSAs
In PRA: we are testing the recipient serum against a small pool of local donor antigen(20-100) using the CDC .The percent of reaction(cell lysis) is reported as PRA . It has its draw backs being non comparable between labs and the recipient PRA may change due a sensitizing event or composition of HLA in the assay utilized.Also, false positive results are encountered with IgM or alloantibodies.
In cPRA: Measures unacceptable antigens to a transplant recipient in a large donor database(10-000 to 12,000). cPRA measures both class 1 and 2 DSA. So, gives an approximation of the patients capable of being transplanted.
References:
1. Merriman L, Greaves M. Testing for thrombophilia: an evidence-based approach. Postgrad Med J. 2006 Nov;82(973):699-704
2. Sullivan, HC, Liwski, RS, Bray, RA & Gebel, HM. The Road to HLA Antibody Evaluation: Do Not Rely on MFI. Am J Transplant 2017; 17: 1455– 1461.
3. Lecture of Prof Ahmed Halawa
Do you think the management was appropriate?
No
This case requires more evaluation as patient has history of DVT and one miscarriage
This case requires thrombophilia screen evaluation:
She will require bridging anticoagulation by LMWH for the peri-operative period
and then recontinuation of postoperative warfarin
MFI 1000 is low risk, induction by ATG/ basiliximab
What is meant by the MFI?
For solid-phase assays such as the commonly used LABscreen, the level of alloantibody is usually expressed as the mean fluorescence intensity (MFI).
MFI levels considered to be positive vary between laboratories and transplant programs, but an MFI level of >1000 generally is accepted as positive
What is the difference between PRA and cPRA?
PRA
cPRA
https://scholars.direct/Articles/transplant-surgery/jts-1-002-table3.html
Knechtle SJ, Marson LP, Morris P. Kidney Transplantation-Principles and Practice E-Book. Elsevier Health Sciences; 2019 Aug 31.
The management is not appropriate.
Suggested management
1) Explore detail history particularly other symptoms suggestive of autoimmune disorders eg SLE, APLS. Previous miscarriage history and detail family history.
2)Workout for autoimmune disorders : ANA/ C3C4/ Anticardiolipin / Lupus anticoagulant
3) Cardiovascular system workout Echo, Cardiac MRI to rule out possibility of intracardiac thrombus, cardiac ischaemia.
4) Duration of anticoagulant depend on the underlying etiology. Provoke or unprovoked. Antiphospholipid syndrome required life long anticoagulant.
5) Explore expectation of recipient for future pregnancy? explain risk of future pregnancy for graft survival.
MFI
Mean Fluorescence Index. Measured the strength of DSA. A high MFI value is often referred to as a high titer antibody.
PRA
Panel reactive antibody ( PRA ) is a complement-fixating assay to test the ability of recipient’s serum to lyse a panel of T-cells from a group of potential donors. It detects only anti-HLA I antibodies and it does not reflect all donor.
CPRA
Calculated PRA .Percentage of donors expected to have HLA antigens listed as unacceptable for a recipient on the waiting list.
Do you think the management was appropriate? How do you manage this case?
I think the management was not appropriate.
34y old female, with h/o DVT (provoked VS unprovoked) and one miscarriage, known ESRD on HD for unknown renal cause and is being worked up for kidney transplantation and has a kidney offer from her cousin.
She needs the following to be done:
1- Thrombophilia work up because of H/O DVT and one abortion.
ANA, anti-dsDNA, Lupus anticoagulant, anti-cardiolipin, protein C, protein S, factor V Leiden mutation, anti-thrombin III, CT-chest, abdomen and pelvis to rule out hidden maliganancy.
2- For how long does she need anti-coagulation?
3- Original kidney disease: she needs kidney biopsy if possible.
Regarding the transplant offer: this a high-risk immunological offer with MM 111, Positive DSA (A1, MFI 1000).
She needs CDC-crossmatch to be done its result will affect the future action:
If positive cross-match–à no transplantation, proceed for desensitization or wait for another donor.
If negative Crossmatch-àtransplantation with high induction IS (ATG or Almetuzumab), triple therapy maintenance (CNI+MMF+Steroids).
What is meant by the MFI?
Mean Fluorescence intensity is used to measure the degree of fluorescence emitted by DSA found on flowcytometry.
What is the difference between PRA and cPRA?
PRA= Panel Reactive Antibody.
It measures the antibodies in the serum of a future recipient against WBC antigens (HLA antigens) of a panel of approximately 100 donors.
High PRA means high chance of positive crossmatch and lower chance of getting a donor from the local population.
c-PRA= calculated Panel Reactive antibody.
c-PRA has replaced PRA since 2007
It calculates the antigens that would be unacceptable. In other wards how sensitized would be the recipient and estimate the chance of being transplanted.
Do you think the management was appropriate?
NO
She needs further evaluation with History of provoked or unprovoked DVT, Any Family History of DVT.
Evaluation for thrombophilia for Protein C, and S, Factor V laiden Mutation, Anti Thrombin III mutaion.
Test for Anti-phospholipid antibodies.She may require Life long Anti-coagulation .
She has cousin as a donor with 111 mismatches and DSA.
Hence She needs further evaluation with CDC cross match, Flow cytometric Cross match. If CDC cross match tuns positive of Flow Cytometric cross match positive with MCS Value >250, we will have to reject the donor or she can be enrolled for KPD.
If CDC cross match is negative and flow cytometric cross match positive with MCS value < 250 we can consider her For desensitization with Ritux, IvIg and TPE.
What is meant by the MFI?
Mean Florescent intensity, A semi-quantitative level of DSA.
The degree of fluorescence exhibited by the presence of alloantibody on Solid phase assay by single antigen bead, in recipient serum, is resulted in terms of its median fluorescence intensity (MFI) and can provide some clue as to the amount and strength of alloantibody present.
Although results are provided as a numerical value, the MFI value cannot be used as a quantitative method.
What is the difference between PRA and cPRA?
Historically the PRA was calculated based on cell based cytotoxicity assay. Where Recipient serum was mixed with pannel of donor lymphocytes, along with exogenous complement and a viability dye.
If the serum contains antibody capable of binding to the donor cells and fixing complement, cell death occurs.
The pattern of reactivity is used to calculate the recipient’s degree of sensitization and likelihood of transplantation.
For example :-if cell death is observed in 45 out of the 60 different cell donors in the panel, the recipient has a panel of reactive antibody (PRA) of 75 percent and would be ineligible to receive a graft from 75 percent of the donor population.
Limitation:
A major limitation of this assay is the difficulty in defining the specificity of the anti-HLA antibody.
False-positive results could arise from the presence of non-HLA antibodies or immunoglobulin M (IgM) HLA and non-HLA antibodies, whereas false-negative results can occur with low titer antibody.
cPRA: Is calculated from Solid phase assay.
In these assays, recipient serum is added to a cocktail of polystyrene beads, to which purified HLA antigens are attached. A fluorochrome-conjugated anti-immunoglobulin G (IgG) detection antibody is then added, and the presence of anti-HLA IgG isotype antibody is identified by flow cytometric methods (Luminex).
The cPRA calculates the likelihood of transplantation by using results of the SAB assay to identify the specificity of the anti-HLA antibodies, in combination with the known frequencies of HLA antigens within the donor population.
As an example, if the patient has an antibody against the HLA-A2 antigen, which is present in 48 % of the United States donor population (phenotypic frequency of the A2 antigen), their cPRA level would be 48 %,
If the patient had an antibody against B44, which is present in 27 % of the population, their cPRA would be 27 %.
If the patient had antibodies against both A2 and B44, their cPRA level would be 59 %.
Solid phase assays are clearly more sensitive than cytotoxic assays.
IgM subtype and Non HLA natibodies does not interefere with the assay.
The process of generating and coupling of HLA antigens to the beads leads to improper protein conformation and/or denaturation, thereby unveiling epitopes that are not naturally found. May Give False positive Test result
The presence of interfering factors in the patient’s serum can also lead to under-recognition of DSA. leading to False Negative result.
Was management appropriate? And how would you manage this case?
Actually no
Pt is young age with history of DVT ,so should have proper history examination and investigations so we can rule out autoimmune diseases ,malignancy and other causes of thrombophilia that cause recurrent thrombosis in the future and in case of renal transplantation thrombosis in the graft and anastomosis and further loss of graft .
So investigations to R/O Antiphospholipid syndrome ,thrombophilia like factor v Leiden deficiency
hematology consultation is essential
Pt may need life long anticoagulation
***There is an increased prevalence of several prothrombotic factors in renal transplant candidates, and thrombophilic patients are at a higher risk for early graft loss. All transplant candidates should have routine coagulation studies performed. Patients who have had a history of thrombosis, including recurrent thrombosis of arteriovenous grafts and fistulas, or spontaneous abortion, should have a more extensive coagulation profile performed. This should include screening for activated protein C (APC) resistance, factor V and prothrombin gene mutations, anticardiolipin antibody, lupus anticoagulant, protein C and S, antithrombin III, and homocystine levels. Approximately 6% of Caucasians have APC resistance, usually as a result of heterozygosity for the factor V Leiden mutation. They are prone to thrombotic complications and graft loss. All renal transplant candidates with systemic lupus erythematosus should have antiphospholipid antibodies measured.
Thrombophilia is rarely a contraindication to transplantation, although its recognition should initiate preventive strategies. Therapeutic decisions for long-term anticoagulation need to be individualized with respect to the agent used and the length of treatment. Chronic anticoagulation of dialysis patients with recurrent access thrombosis but without an underlying coagulopathy is often ineffective and should be avoided. Long-standing warfarin administration has been associated with accelerated vascular calcification. The newer anticoagulation medications may not affect routine coagulation studies and there may be no readily available antidote, so that careful medication history is essential to avoid major bleeding complications.Handbook of danovitch
We recommend not routinely screening for throm- bophilia in candidates (1C).
17.1.1:We suggest screening for thrombophilia
only in candidates who have experienced a venous thromboembolic event, recurrent arteriovenous access thromboses, non-ath- erosclerotic arterial thrombosis, or family history of venous thromboembolism to identify candidates at higher risk of graft thrombosis (2C).KDIGO guidelines
1- Do you think the management was appropriate?
No , I think it was not appropriate .
Because of lack of adequate history,examination, investigation , in order to decide whether the patient has provoked DVT which is treated temporarily with anticoagulant or it is due to thrombophilic state that should be treated life long anticoagualation.
2- How do you manage this case?
Because this young female with unknown etiology ESRD, with history of DVT and miscarriage. Treated with anticoagulant for six month only.
Management should include :
History :
Any provoking factors for DVT .
Any features of SLE .
Family history of thrombophilia
Exam :
SLE features , DVT signs, Periphral vascular disease,
Investigation:
ANA , Anti dsDNA , IgM and IgG Anti cardiolipn Ab, Anti b2 glycoprotein Ab in two occasions 12weeek apart, protein C, protein S, Anti thrombin III, factor five leidin mutation , prothrombin gen mutation.
This patient needs MDT approach, hematologist opinion is important .
The anticoagulation may need to be life long if there is unprovoked DVT , APA, thrombophilia .
Warfarin is a good choice with close follow up by INR ( 2-3). WARFARIN is changed to heparin before 7 day of operation .
As this patient is young with multiple pregnancies, 111 mismatch, with MFI of 1000.
I will treat this patient with r ATG induction AND TAC based triple immunsupressant.
3- What is meant by the MFI?
It is mean florescent intensity, asemiquantitative measurement of DSA level .
The cut of positive test is not standardized , but usually for class I 3000 MFI is considered positive , for class II the positive MFI is is above 5000.
High MFI is associated with high risk rejection .
4- What is the difference between PRA and cPRA?
PRA
1- Indicator of general non-specific reactivity between recipient and potential sample of donors .
2- Measures class-I and class-II antibodies separately
3- High PRA indicates high probability of positive crossmatch with a donor offer
4- Variation in PRA based on laboratory and time of testing
C PRA
1- Calculates specific unacceptable antigens in the wide donor database
2- Class-I and class-II both calculated together
3- Even with a high CPRA, high probability of a negative crossmatch once the organ is offered
4- No variation as it is based on a uniform database
References :
1- Soosay A., O’Neill D., Counihan A., Hickey D., Keogan M. Causes of sensitization in patients awaiting renal transplantation in Ireland. Ir. Med. J. 2003;96:109–112. [PubMed] [Google Scholar] [Ref list]
No, she needs more work to reach an exact diagnosis.
How do you manage this case?
women with abortion and DVT should undergo an immunological investigation for SLE and antiphospholipid syndrome.
needs to be investigated for protein C, S, and factor 5 as thrombophilia screen.
Warfarin should be stop 3- 5 days before operation and replaced by heparin. then re-introduced if there is lifelong indication such as antiphospholipid syndrome.
MFI; mean fluorescence intensity is a measurement of DSA by flow cytometry. it is value range from 1000 — 10000 according to the lab standardization which differs according to the transplant centre. for class I DSA 2000 and for class II 5000 -7500 in most centres.
Using CDC test the recipient,s serum is mixed with donors lymphocytes which consist of 100 pools from different donor blood types. to which complement and vital dye are added. cell lyses occurs if there is complement-fixing antibodies. percentage of cell lyses represent PRA.
c PRA: in which larger number of donor cell pools are used, using 10,000 – 12000 potential donors. c PRA calculated by serology test or by solid phase test such as flow cytometry or Luminex single beads
The patient was not managed appropriately,
Young female with history of DVT and miscarriage will raise a flag to look for
1- autoimmune diseases /connective tissue disease such as lupus and antiphospholipid syndrome.
2- thrombophilia screening for proteinC ,S factor 5 lydin or antithrombin
Ideally she should have a kidney biopsy for proper diagnoses however it is too late now, but still we can screen her biochemically and immunologically.
If screening showed positive for active SLE , then the transplant has to be postpone for at least 6 months.
Similarly the decision for anticoagulation will rely on the cause of her DVT if lupus or antiphospholipid which will requires life long anticoagulation.
If she turn to be lupus /antiphospholipid , I will start her on warfarin however will stop it 4-5 days prior the surgery , will use heparin during instead , and will re start warfarin 24 hrs post surgery.
Mean fluorescence intensity, it is a semiquantitative measure of the DSA level. it is the mean intensity of antibody expression on flow cytometry. It has a different cut off in different laboratories. the higher the MFI signify higher risk of rejection. It varies from 1000 to 10,000 .
Most centers considers 2000for class1 DSA & 5000-7500 for class 2 DSA.
she was not appropriately managed because thrombosis remains a potential complication in this patient post-transplant with unfavourable graft outcomes.
How do you manage this case?
-appropriate work up for thrompophillia and hematological consultation
-patient has 2 pregnancies and abortion need to be considered this with cross matching
-counseled about future pregnancy
MFI : It is a median fluorescence intensity used as measuring unit of DSA antibodies to HLA antigens detected by Flow-cytometry cross match.it expressed as flurescene dye reflection by antibodies.
*PRA : It is a Panel Reactive Antibodies : used to determine if recipient has HLA antibodies. It is done by reaction of a recipient serum against panel of 100 local blood donors white blood cells (lymphocytes ) to identify specific HLA antibodies. Patients having PRA >80% is considered highly sensitized.
While;
*cPRA : is a calculated panel reactive antibody, It calculates HLA antigens which consider to be not acceptable for kidney transplant so , makes the recipient highly sensitized. An individual with higher cPRA will have priority in list of transplantation. Unlike PRA, It provides valuable estimate for transplant in most patients, because it is calculated from unacceptable HLA Ags which will prevent offers from the predictable cross-match incompatible donors. Patient have high CPRA value, will have a high probability of a negative CX.
This is a 34 years old female with unknown renal failure cause, had 2 recurrent abortions and received warfarin for 6 month for DVT, most likely has SLE with anti-phospholipid syndrome or thrombophilia .
A detailed history of fever, skin rash, joint pain, skin ulcers and other systems should be taken.
Investigations should be done to confirm or rule out these differential diagnoses like:
Full immunological screening ANA profile, Ds DNA, anti Smith, anticardiolipin antibodies, anti-phospholipid antibodies etc
thrombophilia screening like factor 5 Leiden, protein c and s, anti-thrombin.
According to the cause, this patient might need life long warfarin therapy.
This patient has DSA A1 with MFI 1000, considered as high risk patient need induction with ATG and maintenance therapy with Tacrolimus, MMF, and prednisolone.
MFI is the measurement of DSA titre by luminex solid-phase assay.
Panel reactive antibody (PRA) testing estimates the percentage of potential donors to whom a recipient has HLA antibodies and approximates the risk of positive cross-match which estimates the risk of rejection post transplant.
Where the calculated panel reactive antibody (cPRA) represents possibility of encountering an incompatible donor for organ transplant candidates and gradually replaced traditional PRA as a measurement of sensitization level.
This is not managed properly as she has DVT and abortion, demand thrombophilia screening. Specially SLE and antiphosphlipid syndrome need to be excluded.
Life long anticoagulantion, hematology consultation, treatment of cause if found any.
The mean intensity of antibody expression on flow cytometry. It is semiquantitative measure of DSA level.
PRA is a panel reactive antibody that involves a recipient serum’s reaction against a pool (20-100) potential blood donor’s lymphocytes to identify specific HLA antibodies. The higher the PRA the higher probability of a positive crossmatch.
c PRA . is the same as PRA but against 10000 to 12000 random donors
Since she is young women, had history of DVT and miscarriage, would like to know other history suggestive of connective tissue disorder ( SLE ) along with non invasive work up which would include APLA work up, ANA, c3, c4 and anti FD DNA. Since she is on dialysis SLE activity usually burns out. More importantly urine microscopy also.
did she undergo kidney biopsy?
Had a history of both arterial and venous thrombosis so need to see the status of iliac vessels by doing DOPPLER as this would be needed for anastomoses.
depending upon her basic disease she might need life long anticoagulation.
she might be having autoantibodies, so CDC might be positive with the donor. We should do autocross match if CDC is positive.
as she is sensitized and MFI of 1000, need to use induction agent ATG and triple immunosuppression thereafter
Proper history taking is the first key for diagnosis .
Our patient is young in her 30’s , she had a DVT , and one abortion .
History of immunological and rheumatological symptoms or signs and tests should be asked about and done .
Is she known to have rheumatological or autoimmune disease ?
History of :
Alopecia
Orogenital ulcers
Arthralgia or arthritis
Malar rash
Discoid rash
Tests for ANA , ADsDNA,C3 ,C4 , tests for antisphospholipid syndrome either 1ry or 2ry : anticardiolopin abs, B2 glycoprotein abs, lupus anticoagulant.
Thrombophilia screening tests should be done too ex: protein S , and C , MTHFR , factor 5 Leiden
Is there a renal biopsy ?
Is it possible to take a renal biopsy now ?
Anticoagulation may be needed to be taken for life in this patient according to the diagnosis .
Determining the 1ry renal disease in this patient is important for determining the proper needed protocol .
For ex: If 1ry immunological disease( SLE -/+ APL) , she will probably need induction , then triple therapy , anticoagulation for life .
If she’s lupus then she may present autoantibodies that may render FCx matching +ve .
Preoperative labs and radiology as usual but cardiological , vascular , psychiatric and chest consultations are of special importance here if SLE.
MFI( which is the unit used to determine the strength of DS’s on flow cytometry) is A1( 1000 ) if crossmatching is -ve ( CDC + DTT or FCx) then no desensitisation is needed
she was not appropriately managed because thrombosis remains a potential complication in this patient post-transplant with unfavourable graft outcomes.
risk stratification should be done for this patient given the history of previous DVT and miscarriage.
primary and secondary APLS should be searched for as well as hereditary and acquired causes of thrombophilia which can result in a chronic prothrombotic state in renal transplant recipients.
Identification of hereditary thrombotic risk factors before transplantation may be a helpful tool for thrombosis prophylaxis short term anticoagulation may be appropriate for this patient after kidney transplantation
Protein C, S, factor 5, anti-thrombin ANA, C3, C4, Anticardiolipin – Anti-beta2 glycoprotein I- and Lupus anticoagulant should be asked for, haematology consultation may be needed.
MFI is a measuring unit used to describe the presence of DSA BY FCXM and their intensity as it expresses the degree of fluorescence dye reflected by the antibodies.
PRA is a panel reactive antibody that involves a recipient serum’s reaction against a panel of 100 potential blood donor’s lymphocytes to identify specific HLA antibodies. The higher the PRA the higher probability of a positive crossmatch.
c PRA . is the same as PRA but against 1000 to 12000 random donors
DVT is not an indication of lifelong warfarin prophylaxis unless recurrent. life-threatening vascular thrombosis is an indication. successful pregnancies drow us far from lupus and related issues, so we do not need lupus anticoagulant or anticardiolipin e.g.
PRA is performed by adding a patient’s serum to a pool of about 100 samples of donor lymphocytes; not very sensitive and not standardized because of the low number and variance among laboratories. On the other hand, cPRA tests against nearly 12000 samples and is more representative of the risk.
references
Soosay A., O’Neill D., Counihan A., Hickey D., Keogan M. Causes of sensitization in patients awaiting renal transplantation in Ireland. Ir. Med. J. 2003;96:109–112. [PubMed] [Google Scholar]
2. Lieber S.R., Perez F.V.T., Tabossi M.R., Persoli L.B., Marques S.B., Mazzali M., Alves-Filho G., de Souza C.A. Effects of panel-reactive antibodies in predicting crossmatch selection of cadaveric kidney recipients. Transplant. Proc. 2007;39:429–431. doi: 10.1016/j.transproceed.2007.01.045. [PubMed] [CrossRef] [Google Scholar]
This is not managed properly as she has DVT and abortion
need to now more details history
any previous symptoms of SLE
one of the differentiational diagnosis of this case is antiphosphlipid syndrome can be primary or secondary with SLE
regarding DVT need to role out all other cause of thrombosis such as protien C,protein S .anticardilipid antibody ,lupus anticoagulant and factor v Leiden
is one of method for antibody screening to identify antiHLA antibodies ,can be provided due to amount and strength of alloantibody present ,MFI threashold above which an antibodis considered postive are not standardized.
Do you think the management was appropriate?
-need to known full history and family history
-Need to investigate the cause of DVT as management differ according the cause
-patient had DVT and miscarriage increase increase possibilty of there is underling cause of thrompophilia mostly in this young lady autoimmune disease like SLE and APS
How do you manage this case?
-appropriate work up for thrompophillia and hematological consultation
-patient has 2 pregnancies and abortion need to be considered this with cross matching
-counseled about future pregnancy
What is meant by the MFI?
Mean Fluorescence Intensity Donor-Specific Anti-HLA Antibodies
What is the difference between PRA and cPRA?
PRA :A panel-reactive antibody (PRA) is a group of antibodies in a test serum that are reactive against any of several known specific antigens in a panel of test cells or purified HLA antigens from cells. It is an immunologic test routinely performed by clinical laboratories on the blood of people awaiting organ transplantation. (wikipedia )
c PRA : Calculated panel reactive antibody (cPRA)
measure whether a patient is sensitized to HLA antigens and to what extent sensitization affects access to transplantation ..(https://www.researchgate.net )
Calculated panel reactive antibody (cPRA) represents possibility of encountering an incompatible donor for organ transplant candidates and has gradually replaced traditional PRA as a measurement of sensitization level.
(https://onlinelibrary.wiley.com/doi/full/10.1111/tri.13015
*Regarding the appropriate management : I think her management was deficient when we revised her available short history , Young female patient with CKD with unknown primary disease ,she had history of DVT and history of miscarriage. So; I would rather think about lupus nephritis , primary or secondary anti-phospholipid syndrome:
SO :
1. Patient should be investigated to exclude SLE and APL with the following labs: ANA ( titre and profile , anti-dsDNA , C3 , C4 , lupus anticoagulant , anti-B2 glycoprotein-I antibody , anti-cardiolipin, 24hours urinary proteins).
2.Exclude causes of DVT by doing thrombophilia profile e.g:( Protein C,s , Anti-thrombin III , MTHFR, Factor V lyedin ).
3.Exclude arterial , small vessels and venous thrombosis by imaging.
4.Renal biopsy has to be done for accurate diagnosis.
Then; patient should be treated according to her diagnosis.
To proceed for renal transplantation off-course after diagnosis her primary kiv=dney disease and exclude lupus activity by the above mentioned labs , she has DSA ( A1 With MFI 1000 ) which considered not that significant so; we will do FCXM and if -ve , will proceed for Renal transplantation with ATG induction consider the patient high risk recipient. Post- transplantation , Anticoagulation should be prescribed .Regular follow-up with DSA , ultrasound and duplex on renal graft every 3-6 months accordingly.
*MFI : It is a median fluorescence intensity used as measuring unit of DSA antibodies to HLA antigens detected by Flow-cytometry cross match.it expressed as flurescene dye reflection by antibodies.
*PRA : It is a Panel Reactive Antibodies : used to determine if recipient has HLA antibodies. It is done by reaction of a recipient serum against panel of 100 local blood donors white blood cells (lymphocytes ) to identify specific HLA antibodies. Patients having PRA >80% is considered highly sensitized.
While;
*cPRA : is a calculated panel reactive antibody, It calculates HLA antigens which consider to be not acceptable for kidney transplant so , makes the recipient highly sensitized. An individual with higher cPRA will have priority in list of transplantation. Unlike PRA, It provides valuable estimate for transplant in most patients, because it is calculated from unacceptable HLA Ags which will prevent offers from the predictable cross-match incompatible donors. Patient have high CPRA value, will have a high probability of a negative CX.
1- Although he has living related donor with acceptable matching and no DSA but he has high CVS risk factor include DM ,ckd on HD ,moderate to sever hypokinesia with Ej fraction 39% and cardiac scintigraphy reported postro-lateral perfusion defect, so need MDT approach involve the cardiologist for further assessment and management before transplantation.
Also need to discuss with patient the risk versus advantage.
After all assessment if patient has no other comorbidities ,there is no non operable 3 vesseles and has no HF with NYHA grate 3 or 4 ,I prefer to proceed after cardiologist clearence.
2-IFyes what the precaution ?
Evolution for the presence of sever cardiac disease ,first history ,identified symptoms of CAD such as anginal symptom ,exercise indolence ,shortness of breath-morbidities and quality of life.
Physical examination :assess the presence of peripheral atrial disease ,anaemia ,HTN,hypotension,abdominal obesity ,Arrythmia ,HF and valvular disease.
Refer to cardiologist for possible angio plastyu so management being considered before transplan such as angioplasty .
Post operative care is need attention such as ICU setting for close monitoring for this patient.
reference
1- Tabriziani H., Baron P., Abudayyeh I., Lipkowitz M. Cardiac risk assessment for end-stage renal disease patients on the renal transplant waiting list. Clin. Kidney J. 2019;12:576–585. doi: 10.1093/ckj/sfz039. [PMC free article] [PubMed] [CrossRef] [Google Scholar]
Do you think the management was appropriate?
It’s not appropriate
Young female less than 40 years with an unknown cause of primary disease, history of miscarriage, DVT, and hypertension, in this case, the hyper-coagulopathy state should be suspected so primary APL syndrome and SLE with secondary APL need to be excluded and the need for lifelong anticoagulation.
– For diagnosing APLS investigation for antibodies should be made
1. Anticardiolipin – 2. Anti-beta2 glycoprotein I- 3. Lupus anticoagulant
-For systemic lupus erythematosus (SLE) Look for
1-ANA profile 3 – 2-complement (C3-C4)
-For thrombophilia disorder: Protein c, Protein S, factor 5, anti-thrombin
How do you manage this case?
This patient considered high risk because
Positive PRA and DSA, pregnancy, and DVT on the other hand she has an acceptable HLA match.
It is important to know the primary disease
So for her DVT, she must be on an anticoagulant therapy (Warfarin- targeting INR 2-3).
For Hyper coagulopathy, states can be referred to a hematologist
▪︎ Regarding transplantation assess the patient’s risk profile by doing FCXM if negative proceed for transplant with ATG, Maintenance with Tacrolimus, MMF, and prednisolone.
Follow DSA level every 3 months post-transplant
What is meant by the MFI?
What is the difference between PRA and cPRA?
Do you think the management was appropriate?
34y old female known case of end stage renal disease on haemodialysis with unknown her original kidney disease she was received offer from her cousin with III mismatches and DSA A1 and MFI 1000 , patient had history of 2 successful pregnancy with one miscarriage and history of DVT
How do you manage this case
What is meant by the MFI?
– the mean intensity of antibody expression on flow cytometry, it is semi quantitative measure of the DSA level.
– different cut off levels in different laboratories.
– high risk of rejectionnelated to higher MFI.
– DSA with similar level of MFI intensity not always activate the complements cascade
– No standanration and normalization of solid phase assay , it is reported that threshold between 1000-10000 which is related to specificity of antigenicity.
– our HLA laboratories cutoff level of 2000 for class I DSA and 5000 for class II DSA
-In PRA where serum of recipient is tested against pool (20-100) of local donor antigens and used CDC in which lymphocytes of donor mixed with serum of patient and rabbit complement and vital dye then lysis of cell done and percentage of reaction is documented as PRA .
-In CPRA, the potential donor ( 10000-12000) , the antibodies in serum recipient detected either:- serological or
– solid phase assays ( ELISA, flow cytometry or Luminex single antigen beads).
*This young lady with history of one miscarriage and thrombophilia presented with unexplained DVT before the age of 40 years she wasn’t managed well as she needs more work up to know:
– cause of renal disease in this age without past medical history
– investigate for antiphospholipide antibidy syndrome and SLE (ANA,ANTI ds DNA ,C3,C4 RENAL BIOPSY ,24 h urine protein, History of other complications in the 2 successful pregnancies as proteinuria and preeclampsia)
-Investigate for thrombophilia (protein c and s,antithrombin III ,Factor V lydein mutation).
Regarding her offer she has DSA A1 With MFI 1000 this MFI is not significant in most centres but CDC-XM and FCXM must be done if negative i will proceed with ATG induction if positive desensitization with plasmapheresis, rituximab and immunosuppression till cross match become negative then induction with basiliximab
Carefull anticoagulation after surgery for fear of renal aretery or vein thromboembolism
And duplex on renal graft every 3 months
*MFI is a measuring unit used to describe presence of DSA BY FCXM as it expresses the degree of fluorescence dye reflected by the antibodies.
*PRA stands for Panel Reactive Antibodies. In order to determine whether or not a patient already has any specific HLA antibodies, a lab specialist will test a patient’s blood (serum) against lymphocytes (white blood cells) obtained from a panel of about 100 blood donors.
These 100 donors represent the potential HLA makeup for a donor from that area.
Percent PRA (%PRA) is the number of reactions within that panel.
* CPRA is based on unacceptable antigens that will prevent offers from those donors to which the patient is most highly sensitized, an offer for a patient with a high CPRA value should mean a high probability of a negative crossmatch.
Unlike PRA, the CPRA provides a meaningful estimate of transplantability for most patients, because it is calculated from unacceptable HLA antigens that will preclude offers from predictably crossmatch incompatible donors
HI Dr Shireen Yousef,
What kind of denominator we have for calculating cPRA?
Ajay
NO
this patient needs more detailed history and physical examination plus investigation trying to :
1- know her primary renal disease ,
2- know the cause of her DVT ( provoked or unprovoked ) and how long she needs to be on anti coagulation .
according the history of DVT and miscarrage plus unknown primary renal disease
so we should do :
about her immunological status , she has moderate to high risk ( history of pregnancy , positive DSA ) and we should do CDC XM if positive – no tranplantaion and looking for other donor if negative we can proceed with transplantation but she needs ATG induction therapy .
Median fluorescence intensity (MFI) is the unit used to measure the expression of donor specific antibodies on flow cytometry by the degree of fluorescence projected by the antibodies, a semi-quantitative measure.
PRA is panel reactive antibody which involves reaction a potential recipient serum against panel of 100 blood donor white blood cell to identify specific HLA antibodies. The higher the PRA the lower the chances of getting a donor for transplant because of higher probability of positive crossmatch
cPRA is calculated panel reactive antibody, these are HLA antigens that has been found to be unacceptable for kidney transplant. These are pooled from sera of past kidney transplant. An individual with higher cPRA will be on priority list for transplant
Exellent
i think it was not managed properly, as her medical history denotes a long term illness { that resultant in stage 5 chronic kidney disease} with peculiar features of deep venous thrombosis, miscarriages and chronic kidney disease. Which might be indicative of underlying connective tissue disease, such as antiphospholipid with or without systemic lupus erythematosus. Treatment thereof might have prevented the progression of the disease to end up in end stage kidney disease.
the main obstacle here is to proceed to transplantation with a clear plan to prevent thrombosis which is a genuine risk in the context of her condition.
Starting with screening for thrombophelia and relevant connective tissue disease. Diagnosing any would assist in stratifying the course and intensity of anti-coagulant therapy implemented peri operatively.
i would consider her as high thromboembolic risk patient and recommend her an anti-coagulation with conventional heparin or LMWH for 3 days prior to the surgery at therapeutic dose.
2 days prior to surgery assess the JNR if more than 1.5 the normal administer vitamin K at a dose of 1 to 2 mg .
for LMWH stop 24 hour before surgery and 4 to 6 hours prior to surgery for UFH..
for post operative course:
LMWH or UFH can be resumed 48-72 hours post operatively.
If the patient is tolerating orally and has no risk of bleeding, warfarin can be started 12 to 24 hours post operatively.
reference:
1-Javier J.Polania Gutierriz,clifford R.Rocuts, Perioperative anticoagulation management.NIH. statpearl.bookshelf, Jenuary 2022
Very good.
MFI,PRA, cPRA??
MFI is mean flouriscent intensity which is a semiquantitative measurement of the donor specific Antibodies and specify its HLA antigens, detected by luminex single antigen bead assay. Its a step in stratification of DSAs significance in ABMR risk and selection for donation.
PRA is the interaction between sera of 100 random donors and the Lymohocytes of a potential recepient.
To indentify the intensity of sensitization towards the HLA of that patient. cPRA is applying same concept but againt 1000 to 12000 random donors, its morz accurate and reflective of the intensity of sensitization againt that recepient HLA antigens.
Dear colleagues,
I am not happy at the suggestion of commencing warfarin at 12 to 24 hours postoperatively in a transplant recipient.
Ajay
This is only for oatient who is having a geniun risk of thrombosis like anti phospholipid syndrom.
◇Do you think the management was appropriate?
In this scenario of a young lady with CKD due to unknown cause and history of DVT and miscarriage we should investigate her for primary antiphospholipid syndrome (APS) or secondary due to SLE.
▪︎APS can be detected by lupus anticoagulant (LA), anticardiolipinantibodies, and/or anti-β₂ glycoprotein I antibody assays [1].
▪︎To diagnose SLE a detailed consideration of the clinical situation plus laboratory investigation is required:
-The antinuclear antibody (ANA) test is the most sensitive test for SLE and is therefore the best screening assay for ruling out its presence.
– Anti-DNA and anti-Sm (Smith antigen) tests are highly specific for SLE [2].
– Also, C3 and C4 levels.
◇ How do you manage this case?
▪︎For her DVT this patient can have Warfarin- targeting INR 2-3 For Hypercoaguable states- Life long anticoagulation with Warfarin- During pregnancy switch to LMWH ▪︎Concerning transplantation it is crucial to evaluate patient’s risk profile and opt for a multidisciplinary approach for the development of appropriate prophylaxis. Induction with ATG Maintenence with Tacrolimus, MMF and prednisolone.
Follow DSA level every 3 months post-transplant.
☆What is meant by the MFI?
▪︎The output of Luminex assay (which can detect HLA antibodies) is a semiquantitative measure referred as the mean fluorescence intensity (MFI)[3].
▪︎It is important to know that Luminex technology is the most sensitive SPA in HLA antibody detection, accompanied by numerous advantages, but not without challenges that need to be overcome, most notably regarding test performance and data interpretation.
▪︎ MFI values are often used as quantitative assessment of antibody strength and used to monitor patients’ clinical status. Though it is a useful tool, there are many more factors to consider in test interpretation. Consequently, MFI values of HLA antibodies represent just a tip of an iceberg and we can partially rely on it [4].
☆ What is the difference between PRA and cPRA?
▪︎Panel-reactive antibody (PRA) is a group of Abs in a test serum that are reactive against any of several known specific Ags in a panel of test cells or purified HLA Ags from cells. The PRA score is expressed as a percentage between 0% and 100%.
▪︎ It represents the proportion of the population to which the person being tested will react via pre-existing antibodies against human cell surface antigens, which include HLA and other polymorphic antigen systems. ▪︎Calculated Panel Reactive Antibody (CPRA) is a formula used to determine what proportion of deceased donors a potential candidate may be immunologically incompatible with and unable to accept organs from; in other words, how “sensitized” a candidate is.
▪︎Unlike PRA, the CPRA provides a meaningful estimate of transplantability for most patients, because it is calculated from unacceptable HLA antigens that will preclude offers from predictably crossmatch incompatible donors. The change to CPRA represents a paradigm shift in many ways. __________________________________________
Ref:
[1] Charis Pericleous et al. Laboratory tests for the antiphospholipid syndrome. Methods Mol Biol. 2014.
[2] L H Calabres. Diagnosis of systemic lupus erythematosus. The value of immunologic tests.
[3]Tait BD. Detection of HLA Antibodies in Organ Transplant Recipients-Triumphs and Challenges of the Solid Phase Bead Assay. Front Immunol 2016; 7: 570
[4]Natasa Katalinic et al. Assessment of Luminex Mean Fluorescence Intensity Values with Complement-Dependent Cytotoxicity Results in Detection of Antibodies Against Human Leucocyte Antigen. BANTAO Journal 2020; 18(1): 24-30
I don’t think she was managed right as more details are required. She is a young female with ESRD of unknown etiology with
– History of previous DVT (not known if was provoked or spontaneous )
– previous abortion ( need more details about the orders of her pregnancies whether the abortion was before or after the other pregnancies and if her pregnancy was complicated by HPN , PE or bleeding , did she received any blood transfusion.
– History of drug intake
– Method of contraception used
– The interval between diagnosing her as ESRD and the abortion
– Full immune profile (ANA, ANCA, C3 , C4 and anti phospholipid Abs)
– Thrombophilia screen
– Renal biopsy if feasible
– Family history of kidney , hypercoagulable state and autoimmune diseases
For this patient
1- I will try to diagnose the cause of ESRD with immune work up and renal biopsy if feasible
2- Evaluate her need for life long anticoagulant or not
3- Assess the immunological importance of her DSA with CDC XM . If T cell CDC XM is positive then this donor will not be accepted. If negative CDCXM will proceed for transplantation using ATG for induction and triple IS ( steroid, Tac and MMF) for maintenance and keep IS trough level at high therapeutic level
If B cell CDC XM is positive , pretransplantation desensitization with PE , IVIG and rituximab may be considered (but we don’t perform desensitization at our center)
What about MFI
is 1000 considered high risk.
Remember B cells carry both class1 and class II.
What about PRA, cPRA
Do you think the management was appropriate?
The patient in the above scenario was not being managed appropriate.
How do you manage this case?
Management of the case will depends on the cause of ESRD and needs a detailed history ruling out the causes of SLE and APS and also malignancies. Detailed investigations which need to be carried out before transplantation in the above case along with baseline investigations include autoimmune markers (ANA, anti-dsDNA, anti-smith,ENA profile,C3 and C4)APLA screening ( lupus coagulant, anti-b2glycoprotein, anticardiolipin antibody), disseminated intravascular coagulopathy (DIC) profile plus thrombophilia screening (Protein C, Protein S, Factor V leiden, antithrombin III).Treatment will depend on the cause –if SLE likely diagnosis then disease should not be active for at least 03 months before transplantation and patient should also be counselled about the disease recurrence. And for APS ,she has to be on warfarin lifelong(INR-2-3).Warfarin should be stopped at least 05 days before transplant and bridged with LMWH and risks associated with anticoagulation (bleeding )and benefits should be told to the surgeon and anesthetist as well. Induction with Basiliximab (111 mismatch with DSA against A1 with MFI of 1000)and maintenance therapy with standard triple regimen(Tacrolimus, MMF and steroids).Warfarin to be started post-operatively and continued life long if APS.
What is meant by the MFI?
MFI (mean florescence intensity) are the measurements which indicate the presence of antibodies against donor specific antigen detected by solid phase assays. .There is no specific cut off for MFI .Every center has its own cut off value –generally MFI>2000 for class I and MFI >5000
What is the difference between PRA and cPRA ?
PRA –a screening test-that gives the likelihood of detecting antibodies (patient serum) present against specific HLA antigens or a panel of typing cells (Lymphocyte from a panel of 100 blood donor) which are prevalent in the population. PRA is usually expressed in percentage form and ranges from 0-100%.Patients having PRA >80% is highly sensitized. Class I and II are measured separately.
cPRA is a better and more accurate test that gives a rough estimate of the patients that can be transplanted and it is usually carried out with the lymphocytes obtained from a very wide donor database. Both class I and II are measured together.
REFERENCE:
1-Sullivan HC, Liwski RS, Bray RA, Gebel HM. The Road to HLA Antibody Evaluation: Do Not Rely on MFI. Am J Transplant. 2017 Jun;17(6):1455-1461
2- Alexander P, Visagan S, Issa R, et al. (October 23, 2021) Current Trends in the Duration of Anticoagulant Therapy for Venous Thromboembolism: A Systematic Review. Cureus 13(10): e18992. doi:10.7759/cureus.18992
Exellent.
In cPRA the antigens of a 10000 to 12000 donors are already registered on a database not lymphocytes.
about the management and how would I manage this case?
the patient needs to be evaluated for possible SLE, APS, inherited thrombophilias. she could have a pathology that requires lifelong anticoagulation. this means she might have increased risk of VTE/thrombophilia perioperatively and thrombogenecity possibly threatening the transplanted vessels. a more detalied obstetric history should be sought as well. in addition, if the patient is found to have SLE, she needs to be evaluated for disease activity. she needs to have inactive disease preferrably 6 months prior to kidney transplantation. in addition, if transplantation is deemed safe, the integrety of iliac vessels should be assessed prior to the transplantation, given the past history of DVT.
about MFI: stands for Mean Flourescence Intensity. it is a measure of antiHLA antibody when solid phase assays are used to quantify antiHLA Abs (as in flow cytometry technique). the higher MFI is, the higher is the possibility of graft rejection and the riskier is the immune profile of the potential recipient
PRA and cPRA:
PRA is Panel reactive antibody, cPRA is calculated PRA
PRA is more of a classic method, compared to the more recent and more accurate cPRA
the idea of PRA (which is done using CDC assays) is measuring the antiHLA Abs present in the potential recipient serum against a panel of HLA angtigens representative of the general population. the more accurate and more recent cPRA is done by solid phase assays and is more specific than PRA done by CDC (specific antibodies against the specific potential donor antigens)
What is the number of tested antigens in PRA compared to cPRA
What are the source of antigens in both.
What is meant by UNACCEPTABLE ANTIGENS by the recipient in cPRA.
Answering these questions will help you understand.
This lady was inappropriately managed via the following:
Identifying the aetiology of ESRD , which has started mostly from her last abortion , DVT and finally before initiation of haemodialysis ,renal biopsy would have been of great value ,full immunological profile regarding auto antibodies ( anti double stranded DNA ,c3 ,c4 ,lupus anticoagulant , protein C , protein S, anti-thrombin III),coagulation profile , CBC , protein to creatinine ratio, antipla2r titre .
History of blood transfusion should be revised if exists.
Menstrual history and contraceptive history.
Family history is required.
Detailed history is required; presence of arthralgia, rash, photophobia, malar rash, headache other thromboembolic events.
History of medications is very important in this lady, either nephrotoxic drugs, contraceptive pills, lupus inducing drugs, NSAIDS.
History of HTN regarding timing related to pregnancy or haemodialysis or abortion, medications used then, aetiology of HTN should be identified too.
History of plasmapheresis, cyclophosphamide, corticosteroids other immunosuppressive agents, either any of them was tried predialysis.
According to risk stratification, she is a high risk recipient as she is young aged, female, history of pregnancies and abortion making her a highly sensitized candidate, history of DVT and abortion may require lifelong anticoagulation with increased risk of bleeding during the perioperative period.
Also having DSAs against A1 group carries more immunological burden as it is considered one of the dominant alleles.
Careful preparation regarding crossmatch, c PRA, autoimmune profile and offering desensitization according to the center’s protocol may be needed mainly by plasmapheresis and rituximab. Immunoadsorption may also be needed after monitoring of DSA titres frequently as they may rise subsequently.
The need of proper anticoagulation should be explained to the patient too.
Correction of comorbid conditions as anemia by ESA to abolish the need of blood transfusion if existed.
Mutltidisplinary team including vascular team, anesthesia, urology as well as other specialties like hematology and immunology would be advised.
Induction by rituximab, with triple therapy immunosuppression in the form of tacrolimus, MMF and corticosteroids is the best unless if contraindicated.
Frequent monitoring of DSA titers post transplantation according to center’s protocol is necessary especially in the first 3 months.
MFI is the mean fluorescence index which reflects the percentage of DSA against donors antigens in the recipient’s blood, in other words it predicts the percent of antigenicity against the donor cells subsequently the allograft, predicting the incidence of graft rejection later on after renal transplantation.
MFI titres above 3000 are considered significant providing being donor specific and require monitoring and desensitization according to the institute’s schedule.
PRA is the panel of reactive antibody, it screens the whole antibodies against the donor and subsequently the graft either class I or class II alleles , it screens also other antibodies which could be nonspecific as for previous infections, pregnancies or blood transfusions.
While calculated PRA is more accurate, reliable and specific to the donor’s antigens with the calculated percent , giving a more precise prediction for the possibility of rejection accordingly the need of desensitization .
Concerning the index patient ranking her degree of sensitsation she does not need aggressive desensitisation protocols.
She has a living donor so you dont need a cPRA.
why antiPLAR!
To exclude membranous nephropathy as an etiology especially after DVT .
for this female patient who is young with the following :
1- ESRD on HD for unknown cause
2- with a history of DVT for which she was treated by warfarin for 6 months. 3- hx of miscarriage once & 2 successful pregnancies
i believe that the management of this case was in appropriate for the follwoing points :
1- efforts had to be done for this case to get information regarding primary renal disorder by renal biobsy ( if not contraindicated at that time)
2- exclusion of autom-immune diseases like SLE by examination , Hx & immune work up had to be done , even if the patient reached ESRD
3- thrombophilia should be done to including screening for factor V and prothrombin gene mutations, anticardiolipin antibody, lupus anticoagulant, protein C and S, antithrombin III, and homocysteine levels , antiphospholipid Abs.
4- detailed obstetric Hx & the miscarriage
5- Hx of the DVT
the association of ESRD in young female with hx of DVT & miscarriage may raise the possibility of SLE with lupus nephritis , APL syndrome either primary or 2ry to SLE , membranous nephropathy with association of thrombotic events
management will differ as following
>>if SLE :
if APL :
>>What is meant by the MFI?
>>What is the difference between PRA and cPRA ?
Panel reactive antibody is a screening test to assess the likelihood of the recipients to have ABs against a donor from that population .
This is done by cross-matching involving serum of the patient and a panel of lymphocytes derived from blood donors among the general population. The result is expressed in form of percentage.
For example, if the patient has a positive cross match (presence of antibodies against the donor lymphocytes) in 60% of cases, the the PRA will be 60%.
Calculated PRA (cPRA) is a form of PRA which is involves using lymphocytes from a large pool of actual kidney donors representing a truer picture with respect to organ compatibility .
more accurate as it is calculated by determining the frequency of incompatible donor HLA phenotypes based on the unacceptable class I and class II HLA antigens that have been listed for each candidate. Since the HLA-A, -B, -C, -DR, and -DQ types of actual deceased kidney donors were used to compute the antigen frequencies, the CPRA reflects the true probability of an incompatible donor based on the unacceptable antigens that have been listed for a patient.
Exellent thankyou
In cPRA the large pool of actual donors have their HLA antigens already in the database and not their lymphocytes.
Not appropriate management.
young female patient
ESRD on HD
Hx of DVT
one miscarriage
DDx of SLE with LN and APLS either 1ry or 2ry
needs proper hx and physical exam besides full work up including
CBC ,INR PT PTT,ANA,ESR,Anti Ds,Anti smith ,urine analysis ,Anticardiolipin antibodies IgG,Anti-beta-2-glycoprotein-I antibodies ,Lupus anticoagulants
other hypercoagulable states (hyperhomocysteinemia, Factor V Leiden and prothrombin mutations, deficiency of protein C, protein S, or antithrombin III.
Doppler ultrasound (US) of the renal arteries (RAs), angio-CT, or magnetic resonance angiography (MRA) looking for renal artery stenosis
Now must be on life long warfarin target INR 2_3
for transplant should be done on high quilified center with MDT including expert nephrologist,cardiologists ,urologist rheumatologist and vascular surgeon
must be prepared will regarding Firstanticoagulation using i.v. heparin seems to be necessary and the perioperative period is a highly risk fearing also from bleeding
and re enterduce oral warfarin after one month from transplant and stabilization
immunosuppressive before and after
median fluorescence intensity measurements of the DSA antibodies to HLA antigens detected by Solid phase assays, which used in cross match as primary test for HLA antibodies
in many centers more than 1000 being positive result and risk for acute and chronic rejection.
PRA indicator of general non-specific reactivity between recipient and potential sample of donors measures class-I and class-II antibodies separatelyHigh PRA indicates high probability of positive crossmatch with a donor offer.
CPRA Calculates specific unacceptable antigens in the wide donor database ,Class-I and class-II both calculated together even with a high CPRA, high probability of a
negative crossmatch once the organ is offered
Very good thankyou
The patient kidney cause of failure need to be adressed as patient is highly sensitised in acount of her previous history of pregnancies ,as well as she is young female , suspected to have autoimmune disease
management should include desensitization by plasmafaresis , IVIG, retuximab with as much as possible lowering level of DSA MFI
MFI mean fluroscence intensity that identify DSA with cutt of value
PRA is a complement test that tested serum recipient against T-cell of donors , while cPRA is the percentage of donors that expected to have unacceptable antigen
references : primer on kidney disease
Do you think the management was appropriate?
It must not be taken smoothly especially there is abortion with DVT which may suggest autoimmune disease as Antiphospholipid syndrome either alone or secondary to lupus
So proper history which include either this DVT was provoked or not abortion in early or late pregnancy and it was spontaneous or provoked also.
How do you manage this case?
As I mentioned good history taking
Autoimmune profile for lupus and APS
For life anticoagulant
Must be maintained on dialysis at least 6 month if lupus diagnosed
What is meant by the MFl?
It is semiquantitative that measures antibodies that directed against HLA present in the recipient serum .
What is the difference between PRA and cPRA?
PRA detects the antibodies t directed to the HLA before transplantation ( preformed antibodies)
Using lymphocytes from small numbers of donors around 100
cPRA uses large pool of donors ,so it is more accurate .
First part is fine .
IMMUNOLOGY needs more work try lecture by Prof. Ahmad Mostafa
Thank Kamal for trying .
you need basic immunology revision for how to classify degree of sensitisation.
Please refer to lecture by Prof. Ahmad Mostafa.
Do you think the management was appropriate?
A young patient-
Cause of ESRD Not known
History of spontaneous DVT
Previous miscarriage
Not a simple business. There is a possibility of autoimmunity or hyper coagulable state.
Warfarin for 6 months after First DVT episode is enough.
DVT and history of miscarriage was overlooked
This patient will require testing to rule out antiphospholipid syndrome -APS or SLE.
For APS-
Anticardiolipin antibodies
Anti B2 Glycoproteins
Lupus anti coagulant
For SLE
ANA, Anti DSDNA. C3,C4
How do you manage this case?
For DVT patient can have Warfarin- Target INR 2-3
For Hypercoaguable states- Life long anticoagulation with Warfarin- During pregnancy switch to LMWH
This case should have induction with ATG and maintenance with Tac, MMF and steroids
What is meant by the MFI?
It is semi quantitative measure of DSA and signifies the intensity of antibody expression on flow cytometry. Risk of rejection is directly related to MFI levels.
Cut off levels for Class 1 DSA- 2000
Cut off levels for Class 11 DSA- 5000
What is the difference between PRA and cPRA
PRA- Panel reactive antibodies- signifies non specific reactivity between recipient and potential sample of donors. PRA measures class1 and class 2 DSA separately. If PRA is high then there is higher probability of positive cross match
cPRA- Measure unacceptable antigens in large donor database. cPRA measures both class 1 and 2 DSA together. High cPRA means higher probability of negative cross match
Reference:
J M Cecka. Calculated PRA (CPRA): The new measure of sensitization for transplant candidates: Special feature. American Journal of transplantation 2009;10(1):26-29.
Exellent Dr Khan
Do you think the management was appropriate?
No!; Patients is highly sensitised with history of miscarriage and DVT possible of antiphospholipids syndrome due to underlying SLE.
How do you manage this case?
Good history and examination to role out systemic SLE
blood screening of SLE (ANA, dsDNA, C3, C4, C1q, antiphospholipids antibodies and renal biopsy protocol before transplant to insurance underlying cause not recurrence post transplant.
Evaluate recipient for PRA and C-PRA because may patient need highly sensitised immunosuppressive agents.
What is meant by the MFl?
Luminex cytometry used for detect donor specific antibodies and HLA antibodies help in cross match prior to transplant.
What is the difference between PRA and PRA?
panel reactive antibody (PRA)-It’s use for detection the rates of unacceptable antigens in sensitized patients.
the calculated PRA (CPRA) level represents the percentage of donors expected to have 1 or more of unacceptable antigens.
Also in management may patient need anticoagulant for ever post transplant and screening for anti thrombi, (Thrombophilia), level of protein C and protein S to be evulated
First part is fine, good start.
Please go to Prof. Ahmad Mostafa in module 1 ,2 for basic immunology.
Needs further evaluation.
I will evaluate cause of DVT and pregnency loss. Possibility of anti phospholipid syndrome.Will do ANA, Anti ds DNA, anti phospholipid antibody and manage accordingly.
MFI is the semiquantitative analysis of HLA antibody.
PRA is the pannel reactive antibody
Try to go bach to Prof. Ahmad Mostafa for basic immunology it will help you a lot.
This 45years old female patient ESKD on hemodialysis with following issues:
1- ESKD of unknown primary cause with history of DVT and one miscarriage.
2- Low titer DSA of 1000 MFI
To manage this case properly depends on knowing the underlying cause of her ESKD if possible by taking detailed history including any possible auto immune disease like SLE with or without antiphospholipids syndrome. Also detailed history about the DVT, weather it’s provoked or not specifically any relation to hemodialysis catheter or prolonged travel or imobilization. Furthermore detailed histroy of the miscarriage, weather it’s in the last pregnancy or not and weather there was obvious other cause than thrombosis. Beside that we need to know weather there was pulmonary embolism or not. After that we need to do thrombophilia screen including antiphospholipids antibodies, protein C, protein S, beta 2 microglobulin and factor 5 Lyden. Depending on that we can decide weather she will need long term anticoagulation if there is irreversible cause of thrombosis.
Regarding the MFI it is abbreviated for mean fluorescent intensity and it’s a semiquantative measure of HLA anti body titer.
The difference between PRA and cPRA is that the later is more accurate as it predicts the possibility of finding suitable donor from a true kidney donors pole unlike PRA which is from blood donors. Unlike PRA, the CPRA provides a meaningful estimate of transplantability for most patients, because it is calculated from unacceptable HLA antigens that will preclude offers from predictably crossmatch incompatible donors.
Ref
American Journal of transplantation volume 10 issue 1 P 26-29
Very good
What will be your management plan pre and perioperative.
Can you give MFI values corrolating to sensitisation.
For perioperative plan, specifically related to anti coagulation need, depends on weather we find a cause for her DVT/miscarriage or not. If irreversible cause is found, then life long anti coagulation with perioperative bridging with heparin, if no cause is found, then we may consider short period of anti coagulation post operative up to 6months.
For MFI cut off to correlate with sensitization it differs between lab and also between class 1 and 2. Generally values above 2000 for class 1 and from 5000 for class 2, some times up to 10000.
This patient should have been investigated for antiphospholipid syndrome, SLE and autoimmune diseases in view of two miscarriages and DVT. We should take a detailed history about DVT (was this provoked or unprovoked) as well as the miscarriage (any previous history from the obstetric). We should always bear in mind other possibility such as Idiopathic membranous GN which can be secondary to an underlying malignancy which of course is associated with thrombotic events.
She will need a multisystem approach review with rheumatologist, haematologist and nephrologist. She will need a thrombophilia screen, coagulation and autoimmune screen.
We need to know if there was any previous history of arterial thrombus which would support APLS. She would require radiological investigations to rule out other possible source of thrombus (arterial and venous) before transplantation (doppler US, MR Pelvis)
From the clinical point of view we should examine the patient for any rash, previous history of pericarditis, pleuritis, arthritis etc to support SLE. We should check for any previous blood test (history of thrombocytopenia, anemia, Complement abnormalities, immunoglobulins etc) that may support our diagnosis
MFI is a semiquantitative analysis of the HLA antibodies in the plasma of transplant recipient. Immunofluorescence assay (IFA) is used to measure the fluorescence intensity of the anti-antibodies targeting the donor specific antibody
Panel reactive Antibody (PRA) detects preformed recipient antibodies (patient serum) using a panel of typing cells (Lymphocyte from a panel of 100 blood donor) and provide a percentage of cells that the serum reacts.
cPRA gives an approximation of the patients capable of being transplanted. Calculates specific unacceptable antigens in the wide donor database
Reference
-Sullivan, HC, Liwski, RS, Bray, RA & Gebel, HM. The Road to HLA Antibody Evaluation: Do Not Rely on MFI. Am J Transplant 2017; 17: 1455– 1461. https://doi.org/10.1111/ajt.14229
-Review Am J Transplant
2010 Jan;10(1):26-9. doi: 10.1111/j.1600-6143.2009.02927.x. Epub 2009 Dec 2.
Calculated PRA (CPRA): the new measure of sensitization for transplant candidatesJ M Cecka 1
Very good
ANY idea how MFI is translated numerically to sensitisation
average figures for anti class1 and anti class2