Presentation on theme: "Grouping and compatibility issues and their resolution 3 rd Basic Haematopathology Course TMH Mumbai."— Presentation transcript:
Grouping and compatibility issues and their resolution 3 rd Basic Haematopathology Course TMH Mumbai
Discrepancy – A conflict or variation …between things that ought to be the same Collins dictionary In the blood bank Reverse typing discrepant with forward grouping Patients phenotype inconsistent with antibody profile Group/type inconsistent with previously assigned group/type Crossmatch results discrepant with prior or subsequent compatibility testing
Classification of grouping discrepancies Group I – Unexpected reactions in serum grouping due to weakly reacting or missing antibodies Group II – Unexpected reaction in cell grouping due to weakly reacting or missing antigens Group III – Unexpected reactions in cell and serum grouping caused by protein or plasma abnormalities Group IV – Miscellaneous problems
General principles for resolution Eliminate the chance of clerical error or misidentification by retesting where possible on a fresh sample. Test with alternate platforms and reagents Use washed cells and saline replacement/dilution to eliminate type III reactions Use enhancement techniques to bring out weak or missing reactions Review and analyse the patients history for a possible role
Lab tests that aid in resolution The tools to him that has the ability to handle them. French proverb Multiple platforms and reagents Antibody screening and identification Non-routine serological tests (enhancement techniques, secretor test, adsorption and elution, etc.) Extended phenotyping Genotyping
Case 1 - Where a discrepancy aided diagnosis! A 55 year old lady slated to undergo an orthopaedic surgery elsewhere, was referred to our blood bank. Results of grouping done elsewhere were:- Anti AAnti BAnti AB A cellsB cellsO cells 4+ 2+ Forward group:ABReverse group:???
Rouleaux – Stacking of erythrocytes in a coin like fashion (right) can be mistaken for agglutination (left) Saline dilution/replacement will neutralise rouleaux formation Microscopy: Rouleaux
With saline dilution reverse group consistent with AB. In view of the clinical history of fracture, patients clinician informed of need to exclude plasma cell dyscrasia. On further investigation, patient diagnosed to have myeloma The presence of a discrepancy may point to a significant clinical condition
Case 2 – Clinical history to the rescue! Sample from a 1 year old child was sent for grouping Grouping results Anti AAnti BAnti AB A cellsB cellsO cells Neg Forward group:OReverse group: AB?
Sample retested after incubation at 4 degrees Celsius showed similar results. Clinical history enquired into:- history of recurrent infections; suspected case of severe combined immunodeficiency syndrome Inference: Serum grouping negative because of hypogammaglobulinemia. Clinical history can play an important role in resolving a discrepancy
Case 3 – A blood group makeover! 59 year old gentleman posted for surgery for carcinoma colon. Previously documented A group Repeat grouping:- Anti AAnti BAnti AB A cellsB cellsO cells 4+2+4+Neg4+Neg Forward group: ABReverse group: A?
Patients serum tested against patients own cells gave a negative reaction Acquired B suspected in view of the above, and clinical history Confirmed by secretor test: Showed only anti A Inference: A group with acquired B
Acquired B phenotype Seen mostly in patients with gastrointestinal lesions, particularly carcinoma colon. Always occur in group A patients, nearly always A1 Acquired B cells do not agglutinate with patients own anti B Secretors do not secrete B substance Reversible on treatment with acetic anhydride Ph sensitive:- Anti B reagents with PH beyond the range of 6.0-8.5 do not agglutinate acquired B cells
oO OO OH CH2OH O Bacterial deacetylating enzymes A immunodminant sugar (N- acetyl D galactosamine) Acquired B (D galactosamine) OH CH2OH OH O B immunodominant sugar (D galactose) O OH CH2OH NHCO- NH2 Bacterial deacetylating enzymes OH O Anti B
Case 4 – An argument in favour of different phases of compatibility testing! A 19 year old youth posted for an elective surgery was grouped in our blood bank. The patient had received 16 uneventful transfusion prior to this Grouping results Anti AAnti BAnti ABA cellsB cellsO cells 4+ Neg Forward group:ABReverse group:AB Antibody screen - Negative
Crossmatch results Phase of testing Donor 1 Group AB Donor 2 Group A Donor3 Group O salineNeg 37 o C3+ Neg Coombs4+ Neg
Patients cells tested with A1 lectin – Negative reaction signifying A2B group Incompatible units tested with lectin and found to be positive signifying A1 phenotype. Crossmatch performed with A2B unit was compatible Inference: A2 with anti A1
Significance:- Anti A1 reactive at 37 o C – clinically significant!! Would have been missed if immediate spin crossmatch alone was done eg. type and screen/electronic crossmatch scenario
Case 5 – Dilemma after resolution! 55 year old lady slated for elective surgery referred from elsewhere. She had received 2 uneventful transfusions of O positive blood elsewhere one year previously. Grouping performed elsewhere. Anti AAnti BAnti AB A cells B cells O cells Neg 4+ Neg Forward group: OReverse group: O
Case 5 – Dilemma after resolution! 55 year old lady slated for elective surgery referred from elsewhere. She had received 2 uneventful transfusions of O positive blood elsewhere one year previously. Grouping performed elsewhere. Anti AAnti BAnti AB Anti H A cells B cells O cells Neg 4+ Neg
Our grouping Phas e Anti A Anti B Anti AB Anti H H lectin A cells B cells O cells poole d O cells dono r1 O cells dono r2 O cells dono r 3 IS/ LISS Neg 4+ Neg 4 O inc Neg -4+ Neg 37 O inc Neg -4+ Neg Coo mbs Neg -4+ Neg 2+ Lewis typing: Le(a-b+) suggesting secretor positive status Inference: Parabombay (O h secretor)
Bombay categories Classificatio n GeneGlycosyltransfe rase AntigensSecreti on Antibodies Bombay (Red cell H deficient, non secretor) hh sese A and/or B None or A and/or B (depending on ABO genotype) in RBC or serum None Anti-A, anti- B, anti-H Parabombay (Red cell H partially deficient, non secretor) hh (weak variant) sese A and/or B (depending on genotype) Weak A and/or B depending on genotype. Weak H in O h.Residual H if A or B enzymatically removed in others NoneAnti H, anti A and/or anti B (depending on ABO genotype) Parabombay (Red cell H deficient secretor) hh Se A and/or B(depending on genotype), H in serum Weak A and/or B depending on genotype and weak H H, A and/or B Weak IH, anti-A and or anti-B
H deficient secretor Little or no A,B and H antigens RBCs may be agglutinated by strong anti-H. Usually not agglutinated by anti-A and anti-B but may occasionally be agglutinated by potent antisera or anti- AB Weak H like antibody (HI) reactive at low temperature almost always present in sera. This is not inhibited by secretor saliva and does not agglutinate cord cells. Normal H levels in saliva Para-bombay (O h secretor) Ulex europaeus (common gorse)
(In red cell H deficient secretors) Anti-HI is unlikely to be active at 37 o C. ABO-identical blood, compatible by ICT at 37 o C, can be used for transfusion. (In H partially deficient non secretors) little information exists on the clinical significance of anti H. Ideally Oh (Bombay) phenotype should be selected, but if not available red cells of the appropriate ABO group (A for Ah, B for Bh) compatible by ICT at 37 o C, may be used. Source: The clinical significance of blood group alloantibodies and the supply of blood for transfusion. (NHSBT specification SPN214/1.1) Bombay blood group not available! Can I transfuse O group cells in Parabombay phenotype?
Case 6 – Transfusion and transplantation 39 year old male with Chronic Myeloid Leukaemia Underwent bone marrow transplant using stem cells from HLA identical sibling Blood group of patient – AB positive Blood group of donor – O positive Received 2 units of compatible O+ve red cells in CMC, 6 days and 3 days prior to transplant
1 day after transplant blood request for 1 unit packed cells received. Forward typing of patient sample – AB+ve Backward typing of patient sample –AB+ve Antibody screen – Negative Issued 1 unit of O positive blood crossmatched and compatible till Coombs 1 day after transfusion haemoglobinuria reported.
Major ABO incompatibility between donor and recipient Minor ABO incompatibility between donor and recipient Major incompatibility for other blood group antigens Minor incompatibility for other blood group antigens Transfusion of erythrocytes incompatible with donor or patient Other causes of immune haemolysis eg. auto immune haemolytic anaemia, drug induced Non immune haemolysis - TTP DD of haemolysis following haematopoietic stem cell transplantation
Major incompatibility between donor and recipient Due to recipient-derived antierythrocyte antibodies Haemolysis immediately after transplant Should be suspected when DCT positive Eluate must be tested for anti A and anti B to identify haemolysis due to ABO mismatch
Volume of erythrocytes in bone marrow HPC product can be equal to or greater than that of a unit of blood. Therefore, significant haemolysis is possible. Erythrocytes can be removed from the donor's bone marrow by Hetastarch separation, mononuclear cell concentration by machine, or through density gradient separation. During apheresis collection, haematocrit should be kept to less than 2% Other methods of prophylaxis include plasma exchange using AB plasma or in vivo adsorption using donor group plasma blood group substances; carry risk of rebound and haemolytic transfusion reactions
Minor incompatibility Usually delayed haemolysis May be due to plasma or passenger lymphocytes Plasma in a bone marrow product to be depleted depending on agglutinin tire. Diagnosis - DCT positive with eluate showing anti A or anti B
Passenger lymphocyte syndrome Donor derived lymphocytes in the HPC graft form blood group specific antibodies to patient erythrocytes Usually ABO antibodies but can involve other blood group antibodies. (Kell, Kidd, Duffy reported) Risk factors inclcude treatment with cyclosporine alone without an antproliferative agent like methotrexate, low intensity conditioning and ?PBSCT (theoretically, since it contains more B lymphocytes) Usually begins 1-2 weeks after transplant, persists for 5-10 days, then subsides Haemolysis can be severe Can involve transfused compatible erythrocytes (bystander immune haemolysis) Management - Transfusion of compatible erythrocytes at a pace that matches haemolysis In massive haemolysis with risk of renal injury, exchange transfusion may be considered
Incompatibility due to other blood group antibodies Supected when DCT is positive and antibody screen positive for donor or recipient The eluate shows an irregular antibody
Investigations in our patient DCT +ve (2+) Post transfusion sample – ICT +ve; antibody screen positive (1+) Antibody ID – anti Jk b (3+) Transfused red cells – Jk b positive Phenotype of stem cell donor- D+; C4+; E-; c4+; e4+; K-; Fy a 3+; Fy b -; Jk a 3+; Jk b 3+ Phenotype of patient – D+; C4+; E-; c4+; e4+; K-; Fy a 3+mf; Fy b 3+mf; Jk a 3+mf; Jk b 3+mf
Inference: Delayed haemolytic transfusion reaction due to anti-Jk(b) formed by patient reacting with transfused cells. Subsequent transfusions with Jk b negative fully compatible units. However, haemoglobinuria persisted until 54 days after transplant, when antibody screen turned negative.
Pure red cell aplasia Occurs in major mismatch Recipient lymphocytes may remain and later produce antibodies to transplanted donor derived erythrocytes Can occur early or late (>100 days) Suppress erythropoiesis by destroying erythroid progenitors Diagnosis – Based on reticulocytopenia persisting for more than 60 days with absence of erythroids in marrow Delayed erythrocyte engraftment occurs in 20% of ABO mismatched transplants ?related to haemagglutinins
Transfusion support in mismatched transplants Must be compatible with recipient and donor Such compatible blood must be selected prior to transplantation (from the start of myeloablation)as red cells may persist for weeks
3 phases of transplantation Phase 2Phase 1Phase 3 Beginning of preparation RBC tx:DCT negative and recipient isoagglutinins not detectable Plasma and platelets tx: Recipient red cells not detectable Recipient group Donor group Compatible with both donor and recipient Transplant
Selection of blood products in phase 2 Recipient RBC group Donor's RBC group Category of ABO mismatch Erythrocyte transfusion Platelet or plasma transfusion AOMinorOA, AB BOMinorOB, AB ABOMinorOAB AMinorA, OAB BMinorB, OAB OAMajorOA, AB OBMajorOB, AB OABMajorOAB A MajorA, OAB B MajorB, OAB ABMinor and majorOAB BAMinor and majorOAB AANoneA, OA, AB BBNoneB, OB, AB AB NoneAB, A, B, OAB OONoneOO, A, B, AB
Blood group chimerism Forward or backward grouping discrepancies and mixed field agglutination Intrinsic characteristic of mismatched transplantation eg. A group recipient transplanted with O group donor Anti -A Anti -B Anti -AB A cell s B cell s O cell s Inference MFNegMFNeg4+NegMixed field on front type may be due to transfused O cells/ conversion. Recipient red cells still seen. Reverse type is recipient group Neg 2+4+NegFront and reverse type donor group, indicating full donor engraftment
Case 7 – ABO mismatch in kidney transplant A 21 year old gentleman of blood group O- positive, with end stage kidney disease Only available related donor was mother whose blood group was A-positive. HLA-crossmatch by Complement Dependent Cytotoxicity (CDC) was negative Anti-A titre at presentation was 1:512. Desensitization protocol involving Rituximab, plasmapheresis and Anti-thymocyte globulin initiated
Column agglutination test used for monitoring Schedule of monitoring: Pre-pheresis, immediately post pheresis and 24 hours later to detect rebound A group FFP used for replacement in order to quench anti A in recipient. Rituximab interfered with HLA CDC crossmatch. HLA antibody monitoring supplemented with solid phase assays Anti A titre reduced to 1:2 against which transplant performed successfully. 3 years post transplant - graft functional, patient well
A brief history of ABO incompatible kidney transplant (ABOi KT) 1955 - earliest efforts by Chung et al. 8/ 10 grafts failed within few days 1987 – Thielke et al transplanted A2 grafts into O donors. 12/20 retained long term function 1987- Alexandre et al used plasmapheresis in protocol and achieved 75% 1 year graft survival From 1989 popularised in Japan (near absence of deceased donors and only 0.15% A2). 14 % of all transplants in Japan. From 2000, gained acceptance in western countries Today, outcome not different from other transplants* *J. M. Gloor and M. D. Stegall, ABO incompatible kidney transplantation, Current Opinion in Nephrology and Hypertension, vol. 16, no. 6, pp. 529–534, 2007.
Principles of ABOi KT Removal of existing antibody – plasma exchange, double filtration plasmapheresis, immunoadsorption Preventing recurrence of antibody – IVIg, immunosuppression, splenectomy/ Rituximab Waiting until titres achieve safe levels for transplantation
Range of Plasmapheresis Treatments required Before and After ABOiKT based on initial antibody titre Lipshutz GS et al. Arch Surg. 2011;146(4):453-458
Monitoring of antibody titre Baseline antibody levels (> 256) predict severity of antibody mediated graft injury and graft survival. Reports suggest this is no longer true in patients that received tacrolimus or mycophenolate mofetil for immunosuppression* Titre cutoff for transplant 16– empirically chosen Titre endpoint based on ?IgG or ?IgG and IgMB. * H. Chung, J. Y. Lee, S. H. Kang et al., Comparison of clinical outcome between high and low baseline anti-ABO antibody titers in ABO-incompatible kidney transplantation, Renal Failure, vol. 33, no. 2, pp. 150–158, 2011.
Possible outcomes of ABOi KT Rejection (2-5%) Immunological tolerance – ABO antibodies against graft do not reaccumulate. ?an outcome of prolonged B cell/ T cell suppression Accomodation – ABO antibodies recur, but the graft is not rejected. Due to ?change in quality of antibody eg. shift in IgG isotype ?change in allograft eg. change in balance of apoptotic proteins bcl-2 and bcl-xl, up regulation of complement inhibitory substance CD59
If we cannot end our differences, at least we can make the world safe for diversity John F. Kennedy Acknowledgement : Dr. Mary Purna Chacko Asst. Prof: Dept of Transfusion Medicine