anti-B Titers Research Articles

Role of plasmapheresis in ABO-incompatible renal transplantation

BackgroundThousands of patients with chronic renal failure die yearly and are unable to have a kidney transplant due to the severe shortage of donors. Therapeutic plasma exchange (TPE) is performed to remove ABO antibodies and permit ABO-incompatible (ABO-I) kidney transplants, but there is only limited research within this area and a lack of standardized protocols for TPE. This article reviews the literature to provide a historical perspective of TPE for ABO-I kidney transplantation and also provides the Johns Hopkins Hospital protocol with a focus on both titers and TPE. Study design and methodsThe TPE treatment plan is based on ABO titers with the goal of a titer of 16 or less at the anti-human globulin (AHG) phase before surgery. Pretransplant therapy consists of every-other-day TPE followed immediately by cytomegalovirus hyperimmune globulin. ABO antibody titers are closely monitored before and after transplantation. After transplantation, TPE therapy is performed for all patients to prevent rebound of anti-A and anti-B titers until tolerance or accommodation occurs. The TPE is discontinued and reinstituted based on the clinical criteria of creatinine levels, biopsy results, and ABO titer. ResultsFifty-three ABO-I kidney transplants have been completed with no episodes of hyperacute antibody-mediated rejection (AMR), and only three episodes of AMR. One-year death-censored graft survival is 100% and patient survival is 97.6%. ConclusionWhile randomized clinical trials are needed to evaluate the optimal method and protocol to remove ABO antibodies, the current literature and our results indicate a critical role for TPE in ABO-I renal transplantation.

ABO antibody titers are not predictive of hemolytic reactions due to plasma-incompatible platelet transfusions.

The overall risk of hemolytic transfusion reactions (HTRs) from plasma (minor)-incompatible platelet (PLT) transfusions and the role of a critical anti-A or anti-B titer in predicting and preventing these reactions has not been clearly established. We evaluated all apheresis PLT (AP) transfusions for 3 months. Using the gel titer method, we determined the anti-A and/or the anti-B immunoglobulin (Ig)G titer for all incompatible APs. Reported febrile transfusion reactions and HTRs were recorded; transfusions were not prospectively evaluated by the study team. A posttransfusion direct antiglobulin test (DAT) and eluate were performed after a reported febrile or hemolytic reaction for patients who received plasma-incompatible APs. A total of 647 of 4288 AP transfusions (15.1%) were plasma incompatible. Group O APs (n = 278) had significantly higher anti-A and anti-B titers than group A or B APs (p < 0.0001). No group A or B APs had a titer of more than 128 (0/342). For group O APs, 73 had titers of 256 or greater (26.3%), and 27 had titers of 512 or greater (9.7%). No HTRs were reported to any plasma-incompatible AP transfusion during the study period. Two plasma-incompatible AP transfusions were associated with fever and chills and positive DATs, of which one had a positive eluate. The incidence of a DAT and eluate-positive febrile transfusion reaction in the plasma-incompatible AP population is 0.15% (95% confidence interval, 0.0%-0.86%). A critical anti-A or -B titer is not sufficient to predict the risk of hemolysis in patients receiving plasma-incompatible APs, although underreporting of reactions to the blood bank may limit the generalizability of this study.

Emergency ABO‐incompatible liver transplant secondary to fulminant hepatic failure: Outcome, role of TPE and review of the literature

The increasing demand for solid organ transplants has brought to light the need to utilize organs in critical situations despite ABO-incompatibility. However, these transplantations are complicated by pre-existing ABO antibodies which may be potentially dangerous and makes the transplantation prone to failure due to rejection with resulting necrosis or intrahepatic biliary complications. We report the clinical outcome of an emergency ABO-incompatible liver transplant (due to fulminant hepatic failure with sudden and rapidly deteriorating mental status) using a modified therapeutic plasma exchange (TPE) protocol. The recipient was O-positive with an initial anti-B titer of 64 and the cadaveric organ was from a B-positive donor. The patient underwent initial TPE during the peri-operative period, followed by a series of postoperative daily TPE, and later a third series of TPE for presumptive antibody-mediated rejection. The latter two were performed in conjunction with the use of IVIg and rituximab. The recipient's anti-B titer was reduced and maintained at 8 or less 8 months post-op. However, an elevation of transaminases 3 months post-transplant triggered a biopsy which was consistent with cellular rejection and with weak C4d positive staining suggestive of antibody mediated rejection. Additional plasma exchange procedures were performed. The patient improved rapidly after modification of her immunosuppression regimen and treatment with plasma exchange. This case illustrates that prompt and aggressive plasma exchange, in conjunction with immunosuppression, is a viable approach to prevent and treat antibody mediated transplant rejection in emergency ABO-incompatible liver transplant.

Immune hemolysis after fludarabine-based reduced intensity conditioning and allogeneic PBSC transplantation for CML with minor ABO incompatibility

Dear Editor, Fludarabine is commonly used in reduced intensity conditioning (RIC) regimens and has been linked to immune hemolysis [1, 2]. We report the first case of severe immune hemolysis in the fludarabine-based RIC allogeneic peripheral blood stem cell transplantation (PBSCT) for chronic myelogenous leukemia (CML) in the setting of minor ABO incompatibility. A 47-year-old woman diagnosed with CML underwent allo-PBSCTwith an HLA-matched related donor in February 2007, while in the accelerated phase. Conditioning consisted of busulfan, 2 mg/kg/day (days −6 and −5), fludarabine, 30 mg/m2/day (days −6 to −2), and anti-thymoglobulin, 10 mg/kg/day (days −4 to −1). GVHD prophylaxis consisted of cyclosporine, 5 mg/kg/day, and mycophenolate mofetil, 45 mg/kg/day. There was minor ABO incompatibility between the donor (O Rh-positive) and the recipient (B Rhpositive). The donor's anti-B antibody titer in saline test tube at 37°C was 1:8 IgG. The conditioning regimen and stem cell infusion were both uneventful. Eight days after PBSCT, she developed mucocutaneous pallor, asthenia, and nausea. Laboratory studies indicated severe hemolysis with a drop in the hemoglobin level, an increase in the serum bilirubin and lactic dehydrogenase (LDH) levels, and complete disappearance of haptoglobin (graph). Peripheral blood contained spherocytes. No fragmentation was observed. Renal function and clotting studies were normal. Thorough microbiological studies were negative. Investigations for hepatitis A, B, and C viruses, VDRL, HTLV I and II, HIV, HSV, adenovirus, parvovirus, EBV, HHV-6, cytomegalovirus, and toxoplasmosis were negative. Computed tomography (CT) of the chest and sinuses was normal, and CT of the abdomen showed only splenomegaly. Serological screening for autoimmune diseases was negative. None of the medications she was receiving was known to cause hemolysis. The direct antiglobulin test (DAT) was positive for IgG and C3d. Recipient red blood cells (RBC) were repeatedly B positive. The serum anti-B antibody titer in saline test tube at 37°C was 1:2 IgG. Antibodies eluted from the patient's RBCs showed pan-agglutination against group O antibody panel cells. Allo-antibodies were excluded by adsorption studies. The diagnosis of immune intravascular hemolysis was established. The lowest recorded hemoglobin level was 5 g/dl, and the highest levels of bilirubin and LDH were respectively 7 mg/dl (normal, 0.2 to 1.0 mg/dl) and 791 IU/ l (normal, 120 to 200 IU/l). Methylprednisolone, 2 mg/kg/day intravenously, was administered from day +8 for five consecutive days and was then gradually withdrawn over 2 months. The hemoglobin level improved rapidly, and the hemolysis panel normalized (Fig. 1). Repeated anti-B titers in saline test tube at 37°C were respectively 1:8 and 1:16 on days +11 and +14. On day +14, the DAT was negative, and the patient's blood group was O Rh positive. She received a total of six units of type O Rhpositive packed red blood cells from days +10 to +13, and no further transfusions were necessary. VNTR analysis on R. Calixto : F. Ostronoff :M. Ostronoff :A. Sucupira : R. Florencio :A. P. S. Maior :M. C. Domingues Hematology and Bone Marrow Transplantation Unit, Real-Hospital Portugues, Recife, PE, Brazil

Successful paediatric ABO incompatible renal transplantation with quadruple immunosuppression and B lymphocyte depletion

<h3>Aims</h3> ABO incompatible renal transplantation has been reported as a successful form of renal replacement therapy in children and adults. Antibody removal is required with options of B lymphocyte depletion with splenectomy, plasma exchange, double filtration plasmapheresis or immunoadsorption. <h3>Methods</h3> To report the successful outcome of ABO incompatible renal transplantation using quadruple immunosuppression (basiliximab at days 0 and 4, mycophenolate mofetil and tacrolimus from one week pretransplantation and corticosteroids) with only B lymphocyte depletion (intravenous rituximab 375 mg/m² at one month pretransplantation). A 14-year-old young man received a living related renal transplantation from his mother for end-stage renal failure (ESRF) on haemodialysis for steroid resistant nephrotic syndrome due to focal and segmental glomerulosclerosis (FSGS) who had a living related renal transplant from his father 18 months previously, which had failed due to a vascular event. <h3>Results</h3> The recipient and donor (mother) blood groups were A and B Rhesus positive, respectively, with anti-B titres of one in four rising to one in eight pretransplantation. His renal transplant was performed successfully without further antibody removal or surgical complications and immediate renal allograft function. Three months posttransplant his renal function has stabilised with a plasma creatinine of 114μmol/l giving an estimated glomerular filtration rate of 62 ml/min/1.73 m². He does not have clinical evidence of recurrent FSGS posttransplantation (normal serum albumin levels without albuminuria) with negative anti-B titres and donor specific antibodies and no evidence of EBV, BK or CMV viraemia (having required oral valganciclovir as CMV mismatch). He had a normal transplant renal biopsy at ten days post-transplant without evidence of acute rejection and one focal segmental sclerotic lesion seen on protocol biopsy at three months. <h3>Conclusion</h3> In view of the reported success of ABO incompatible renal transplantation, clinicians must consider this option in ESRF patients whose parents have been excluded as living donors in view of ABO blood group incompatibility.

Management of jaundice in newborn nurseries – measuring, predicting and avoiding the sequelae

This issue of Acta Paediatrica contains three studies of neonatal jaundice (1–3), each in its own way adding to our ability to manage neonatal jaundice safely. Although neonatal jaundice is so common as to perhaps be considered banal, few issues in neonatal care appear quite as vexing as the management of the jaundiced infant. Thus, we are faced with imprecision in measurement, imprecision in treatment and uncertainty in prediction. No wonder that we appear unable to avoid the tragedy of kernicterus (4). Measurement of bilirubin has been performed for decades mostly on blood samples (whole blood, plasma or serum). Although there is a plethora of methods available for such analysis, none appears perfect judging by the many complaints about the lack of precision in bilirubin measurements (5). A large manufacturer of analytical equipment recently announced that they had decided to shift their bilirubin standard (down) by 9%, recognizing that the numbers which had previously been reported from their machines had differed by that percentage. Not surprisingly, attempting to estimate the serum bilirubin value by measuring bilirubin in the skin is affected with even greater imprecision. In spite of this, transcutaneous measurement of bilirubin (TcB) has become a common method to screen neonates for jaundice. If TcB values are used, not to make treatment decisions, but simply to decide whether or not a blood test is needed, many unnecessary blood tests can be avoided. One of the pitfalls of TcB has been the contribution of non-bilirubin pigments (such as melanin) in the infants’ skin to the value read by the machine. Wainer et al. (1) have aimed to improve on previous studies by assessing the infants’ skin colour according to two defined reference colours, rather than by racial assignations or other visual estimates of skin colour. Using the Minolta ⁄AirShields JM-103 jaundice meter, which was designed to minimize the impact of melanin on measurements, the authors found the best precision and lowest bias in infants judged to be of ‘medium’ skin tone, i.e. between the two reference colours. The generalizability of their results is limited by the fact that only 1.9% of the studied infants had ‘dark’ skin colour. In addition, it seems that whereas the assignation into the three colour categories was performed in 79% of the cases by the study coordinator, and thus less subject to inter-observer variability, the lighting conditions under which skin colour assignment was made are not described or defined in the study. There may be two challenges here, one being that the colour assignment may not work quite as well as when performed as it probably would be under normal working conditions, by a larger group of different people. The other problem is that an assessment of colour is likely to vary with the strength and colour of ambient light. Nevertheless, studies like this are important because they highlight the strengths as well as limitations of methods in routine use, and thus are likely to make us more attentive to their potential pitfalls. In recent years, the length of stay in maternity hospitals and birthing units has become shorter. Thus, for many Invited Commentary for Wainer et al. Impact of skin tone on the performance of a transcutaneous jaundice meter, Bakkeheim et al. Maternal IgG anti-A and anti-B titres predict outcome in ABO-incompatibility in the neonate, Bental et al. Bhutani-based nomograms for the prediction of significant hyperbilirubinaemia using transcutaneous measurements of bilirubin. Acta Paediatrica ISSN 0803–5253

Probiotic‐associated high‐titer anti‐B in a group A platelet donor as a cause of severe hemolytic transfusion reactions

Hemolytic transfusion reactions (HTRs) can occur with transfusion of platelets (PLTs) containing ABO-incompatible plasma. Reported cases have involved group O donors. Two cases of PLT-mediated HTRs associated with the same group A plateletpheresis component, collected from a donor taking high doses of probiotics are reported. Case 1 was a 40-year-old 69-kg group B stem cell transplant patient who received one-half of a group A plateletpheresis component. Severe back pain occurred 10 minutes into the transfusion, accompanied by anemia and hyperbilirubinemia. Case 2 was a 5-year-old 26-kg group B male with aplastic anemia who received the other half of the same plateletpheresis component, volume reduced to 37 mL. Syncope occurred immediately after the transfusion, with laboratory evidence of hemolysis a few hours later. Serologic investigation of posttransfusion samples from both patients revealed positive direct antiglobulin tests: C3d only for Case 1 and immunoglobulin (Ig)G and C3d for Case 2; the eluates contained anti-B. The group A donor's anti-B titer was 16,384 at saline and IgG phases. Donor lookback revealed that the donor had donated 134 apheresis PLTs over many years. For 3 years, he had intermittently taken probiotics; 3 weeks before the index donation, he began taking three tablets of probiotics every day. Lookback of prior group B recipients uncovered a case of acute hemolysis that was not recognized at the time. The solubilized probiotic inhibited anti-B in vitro. Non-group O PLT donors can have high-titer anti-A or anti-B that might mediate HTRs, and probiotic ingestion in blood donors represents a novel mechanism of stimulating high-titer anti-B.

International collaborative study to evaluate candidate reference reagents to standardize haemagglutination testing for anti‐A and anti‐B in normal intravenous immunoglobulin products

The aim of the study was to evaluate, in an international collaboration, three lyophilized intravenous immunoglobulin (IVIG) preparations for their suitability to standardize and control haemagglutination testing for anti-A and anti-B in IVIG products. Twenty-three laboratories tested candidate IVIG reference reagents consisting of a Positive control (07/306), a Negative control (07/308), and a specifically formulated Limit preparation (07/310) to define the maximum (e.g. pharmacopoeial) limits of anti-A and anti-B in IVIG products, where limits are applicable. Laboratories performed direct haemagglutination using papain-treated erythrocytes and/or indirect antiglobulin tests. For both methods, there was up to 16-fold variation in anti-A and anti-B titres, although there was good agreement over a two-fold titre range for anti-A and anti-B between laboratories for both 07/306 and 07/310 using the direct method. Comparative titration data for 07/306 and 07/310 indicated that the use of a 'Limit' reference reagent would facilitate identification of higher titre batches when the direct haemagglutination method is used. The establishment of preparations 07/306, 07/308 and 07/310 as reference reagents by the World Health Organization will facilitate global standardization of haemagglutination tests for anti-A and anti-B, ensure that such tests are sufficiently sensitive and specific, and facilitate identification of batches that exceed maximum recommended levels of anti-A and anti-B. The Commission of the European Pharmacopoeia and the United States Food and Drug Administration have adopted the same reference reagents including the maximal specifications defined by preparation 07/310.

The critical role of plasmapheresis in ABO‐incompatible renal transplantation

Thousands of patients with chronic renal failure die yearly and are unable to have a kidney transplant due to the severe shortage of donors. Therapeutic plasma exchange (TPE) is performed to remove ABO antibodies and permit ABO-incompatible (ABO-I) kidney transplants, but there is only limited research within this area and a lack of standardized protocols for TPE. This article reviews the literature to provide a historical perspective of TPE for ABO-I kidney transplantation and also provides the Johns Hopkins Hospital protocol with a focus on both titers and TPE. The TPE treatment plan is based on ABO titers with the goal of a titer of 16 or less at the anti-human globulin (AHG) phase before surgery. Pretransplant therapy consists of every-other-day TPE followed immediately by cytomegalovirus hyperimmune globulin. ABO antibody titers are closely monitored before and after transplantation. After transplantation, TPE therapy is performed for all patients to prevent rebound of anti-A and anti-B titers until tolerance or accommodation occurs. TPE is discontinued and reinstituted based on the clinical criteria of creatinine levels, biopsy results, and ABO titer. Fifty-three ABO-I kidney transplants have been completed with no episodes of hyperacute antibody-mediated rejection (AMR) and only three episodes of AMR. One-year death-censored graft survival is 100 percent and patient survival is 97.6 percent. While randomized clinical trials are needed to evaluate the optimal method and protocol to remove ABO antibodies, the current literature and our results indicate a critical role for TPE in ABO-I renal transplantation.

Anti‐A and anti‐B titers in pooled group O platelets are comparable to apheresis platelets

Although uncommon, acute hemolytic transfusion reactions (AHTRs) have been reported after transfusion of group O single-donor apheresis platelets (SDPs) to group A, B, and AB recipients. Current methods for identifying "high-titer" SDPs include tube and gel methods. The risk of a high-titer unit is considered low with group O, poststorage, pooled platelet concentrates (PPLTs); however, data regarding anti-A and anti-B titers in PPLTs are lacking. Anti-A and anti-B titers were determined in 185 PPLTs by direct agglutination using manual gel and tube methods. PPLTs tested included 124 group O PPLTs, 25 group A PPLTs, 26 group B PPLTs, and 10 PPLTs containing a mix of either groups O plus A or groups O plus B (mixed PPLTs). The reciprocal of the highest dilution giving macroscopic agglutination was considered the agglutinin titer. Mean anti-A and anti-B titers in group O PPLTs were, respectively, 16 and 8 by tube and 64 and 32 by gel (p < 0.0001). Gel titers were one to two dilutions higher than tube and sensitive to reagent red cell lots. With the use of at least 64 as a critical titer, 60 percent of group O PPLTs tested by gel would be considered high-titer. In mixed PPLTs, the addition of one non-group O PLT significantly decreased or neutralized the corresponding anti-A or anti-B (p < 0.0001). Anti-A and anti-B titers in group O PPLTs are comparable to those reported in group O SDPs and significantly lower than titers reported in AHTR. A critical direct agglutinin titer of 64 for identifying high-titer units by gel is too low and should be increased to 128 or higher.

Thrombotic Microangiopathy After ABO-Incompatible Living Donor Liver Transplantation: A Case Report

Thrombotic microangiopathy (TMA) has rarely been reported in the setting of liver transplantation. Herein we have reported a successful case of TMA after ABO-incompatible living donor liver transplantation (LDLT) treated with plasma exchange and high-dose intravenous gamma-globulin infusion. A 50-year-old woman was diagnosed with hepatitis C virus-related cirrhosis. We performed an ABO-incompatible LDLT (group B to O) with preoperative plasma exchange to reduce the anti-B hemagglutinin titers to 1:8. The immunosuppressants consisted of tacrolimus, mycophenolate mofetil, and steroid. On postoperative day (POD) 8, her anti-B hemagglutinin titer suddenly increased to 1:64. The serum lactate dehydrogenase (LDH) level was grossly elevated (1518 IU/L). On POD 13, we suspected infection of an intra-abdominal hematoma ( Serratia marcescens) which was drained surgically. On day 5 after the reoperation, thrombocytopenia developed with a platelet count of 3×10 4/mm 3. A peripheral blood film showed severe red blood cell (RBC) fragmentation. Thus, we made a clinical diagnosis of TMA and reduced the tacrolimus dose. We started intensive daily plasma exchange (4 L/d) with fresh frozen plasma and high-dose intravenous gamma-globulin infusions. One week thereafter, thrombocytopenia improved with reduced transfusion requirements. The peripheral blood film showed normal RBC morphology. The serum LDH returned to baseline levels. Four factors were considered to have caused TMA in this case: the prescription of tacrolimus, ABO-incompatible liver transplantation, bacterial infection, and surgical stress. These factors may have all contributed by causing significant endothelial injury and TMA.

Haemolytic disease of fetus and newborn caused by ABO antibodies in a cisAB offspring

ABO hemolytic disease of fetus and newborn (ABO-HDFN) occurs almost exclusively in infants of blood group A or B who are born to group O mothers because IgG anti-A or -B occurs more commonly in group O than in group A or B individuals. We report a case of clinically significant ABO-HDFN where the mother was blood group O with elevated IgG anti-A and anti-B titers and delivered a child with an A 2B phenotype. This unusual ABO constellation between mother and infant was based on the inheritance of a rare ABO allele encoding for a glycosyltransferase capable of synthesizing both A and B antigens. Because both anti-A and anti-B antibodies may have been involved in hemolysis in this case, it may be relevant to consider the cisAB phenomenon when monitoring ABO-incompatible pregnancies and births.

Properties of a concentrated minipool solvent‐detergent treated cryoprecipitate processed in single‐use bag systems

Cryoprecipitate is still used to treat factor VIII (FVIII), von Willebrand factor (VWF) and/or fibrinogen deficiency. Recently a solvent-detergent (S/D) process of minipools of cryoprecipitate performed in a closed bag system has been designed to improve its viral safety. Still, cryoprecipitate has other drawbacks, including low concentration in active proteins, and presence of haemolytic isoagglutinins. We report here the biochemical evaluation of S/D-treated minipools of cryoprecipitates depleted of cryo-poor plasma. Cryoprecipitates were solubilized by 8 mL of a sterile glucose/saline solution, pooled in batches of 40 donations and subjected to S/D treatment in a plastic bag system using either 2% TnBP or 1% TnBP-1%Triton X-45, followed by oil extractions (n = 10). Mean (+/-SD) FVIII and fibrinogen content was 8.86 (+/-1.29) IU mL(-1) and 16.02 (+/-1.98) mg mL(-1), and 8.92 (+/-1.05) IU mL(-1) in cryoprecipitate minipools treated with 2% TnBP, and 17.26 (+/-1.71) mg mL(-1), in those treated by TnBP-Triton X-45, respectively. The WWF antigen, ristocetin cofactor and collagen binding activities were close to 10, 7 and 8 IU mL(-1), respectively, and were not affected by either SD treatment. VWF multimeric pattern of SD-treated cryoprecipitates were similar to that of normal plasma, and the >15 mers and >10 mers content was identical to that of the starting cryoprecipitates. The anti-A and anti-B titre was 0-1 and 0-1/8, respectively. Therefore, it is possible to prepare virally inactivated cryoprecipitate minipools depleted of isoagglutinins and enriched in functional FVIII, VWF and clottable fibrinogen.

Delayed intravascular haemolysis following multiple asymptomatic ABO-incompatible red blood cell transfusions in a patient with hepatic failure

ABO-incompatible red blood cell (RBC) transfusions have rarely been associated with delayed haemolysis. However, we report the case of a 75-year-old man (blood type O) with hepatic disease, who received 5 units of incompatible type B RBCs over 8 days. The patient did not develop symptomatic or biochemical evidence of haemolysis until 7-8 days after the first incompatible RBC unit. The patient had a low anti-B antibody titre (1 : 64) prior to the first transfusion. The onset of haemolysis was temporally associated with an increase in anti-B and the infusion of fresh-frozen plasma. In conclusion, a patient with hepatic failure experienced a delayed haemolytic transfusion reaction after receiving multiple ABO-incompatible RBC transfusions that were initially well-tolerated. We speculate that the delayed haemolysis may have resulted from an anamnestic antibody response to the initial incompatible transfusion, or possibly as a result of the transfusion of fresh-frozen plasma, which might have repleted low complement levels.

Investigation of Intragam® P Haemolysis Adverse Events

Aim To understand the underlying cause of a cluster of haemolysis-type adverse event (AE) reports received by CSL/ARCBS in patients receiving Intragam® P. Method The cluster of AE reports were analysed with respect to patient factors (clinical indication, dose, blood group, concomitant medications and blood products, bone marrow reserve), product factors (batch results, production records) and changes in clinical practice (administration protocols, infusion kits). All Intragam P haemolysis related AEs from clinical trials and post-marketing exposure were reviewed, as well as international literature on this subject. Result Sixteen haemolysis type cases were reported to ARCBS/CSL over a 3 month period, ranging from abnormal laboratory test results (positive Coombs test) to clinical symptoms requiring transfusion. Ten of these reports were received in 4 days from 2 Victorian hospitals following the detection of 2 cases, which precipitated a retrospective review that identified additional similar cases. All patients received high dose (doses exceeding 400–600 mg/kg given every 3–4 weeks either in frequency or quantity) and all but one (where evidence suggested an underlying disorder) were of blood group A or AB. Eight patients were recipients of bone marrow transplants. No product or batch related factors or processes likely to have contributed to the haemolysis type AEs were identified. Anti-A and Anti-B titres of all Intragam P batches were investigated and confirmed to be within regulatory approved release specifications and pharmacopoeial limits. Conclusion Haemolysis type adverse events are a recognised consequence of IVIG administration and are widely discussed in the literature. This investigation has confirmed the association of high dose IVIG in recipients of blood group A or AB and increased risk of haemolysis type adverse events. It also highlighted the possibility of accentuating any consequent anaemia in patients with diminished bone marrow reserve (eg post bone marrow transplant patients). Pre-infusion ABO blood groups should be determined in patients receiving high dose IVIG and their haemoglobin levels monitored in the days following therapy.

Differences in ABO antibody levels among blood donors: a comparison between past and present Japanese, Laotian, and Thai populations

Abstract Passively transfused blood group antibodies cause clinical problems. High titers of anti-A and anti-B seem to be one reason for hemolytic transfusion reactions and for ABO HDN. In Japan, anti-A and anti-B titers notably decreased in the 15 years between 1986 and 2001. At present, titers of more than 100, as measured using the saline method, are rare. Differences in the level of anti-A and anti-B among ethnic populations have been reported; these differences were found to be the result of environmental factors rather than hereditary factors. In the present study, the anti-A and anti-B titers of random donors in three Asian populations are compared. In Thailand, the IgM anti-A and anti-B titers are low and are similar to the Japanese titers reported in 2001, but the IgG anti-A and anti-B titers are high and are similar to the Japanese titers reported in 1986. In the Lao People’s Democratic Republic, both the IgM and the IgG anti-A and anti-B titers are high and are similar to those reported in Japan in 1986. In addition, anti-A and anti-B titers of different sex donors and of various age groups were also compared. High titers were found in 8.8 percent of the female donors in the younger than 30 age group and in 36.7 percent of the female donors in the older than 50 age group. Immunohematology 2007;23:38–41.

Development of a Novel ELISA for Detection of Anti-A and Anti-B Antibodies in Recipients of ABO-Incompatible Living Donor Liver Grafts

The survival rate in ABO-incompatible (ABO-I) liver transplantation was much lower than that in ABO-compatible recipients for the early experiences. It is therefore essential to develop the precise and fast measurement of anti-A and anti-B antibodies (Abs) to prevent humoral rejection in ABO-I liver transplantation. Agglutination titer has been the standard method to measure these Abs, but the interpretation of the results is subject to bias. Here, we have developed an objective and quantitative enzyme-linked immunosorbent assay (ELISA) to measure anti-A and anti-B Abs. This test requires only a small amount (10 microl) of recipient's serum. We applied the newly developed ELISA to monitor living donor liver transplant recipients and investigated the correlation between ELISA and agglutination titer. The Spearman's correlation coefficient for Abs ranged from 0.461 to 0.812. Moreover, in one case of humoral rejection, the increase of Abs was detected by ELISA one day earlier than by the agglutination titer. In conclusion, our ELISA method proved useful to detect an increase of anti-A and anti-B Abs titers at an early stage, thereby contributing to a prompt treatment of humoral rejection due to ABO-I.

Experience With Laparoscopic Splenectomy for ABO-Incompatible Living Renal Transplantation Without Plasmapheresis

A 25-year-old male, blood type A, was admitted to our hospital for renal transplantation from his father of AB blood type. Before transplant, we performed laparoscopic splenectomy. The serum anti-B antibody titer fell from 1:8 to 1:2. Therefore, plasmapheresis was not performed. The total ischemic time was 80 minutes. Five immunosuppressive agents, including tacrolimus, mycophenolate mofetil, prednisolone, basiliximab, and deoxyspergualine, were administered in the initial period. On the 47th day, value of cytomegalovirus antibody, which was routinely measured, became positive. Hence, we administered ganciclovir, with a fall in antibody. Sixty-five days after transplant, he was discharged with a serum creatinine of 1.0 mg/dL. We concluded that it was possible to perform ABO-incompatible renal transplantation with no need for plasmapheresis or rituximab.

Resolution of ABO Discrepancies by ABO Genotyping

Before a blood transfusion, both red cell and serum typing need to be matched for ABO tests on the donor and patient (recipient). When a mismatch exists in the tests, additional ABO genotyping and serological tests are required for the resolution of the discrepancy. We performed ABO genotyping on a series of blood donors and patients with ABO discrepancies to assist in resolving their blood groups. We examined 46 samples with ABO discrepancies from a random pool of donors recruited at Gwangju-Chonnam Red Cross Blood Center and from patients at Chonnam National University Hospital between May 2004 and July 2005. ABO genotyping was performed on all samples with an allele specific polymerase chain reaction for differentiation of A, B,O, cis-AB, A(var) (784 G>A), and B(var) (547 G>A) alleles; routine serologic tests were also performed. Exon 6 and 7 of ABO gene from five samples were sequenced. The genotypes of 18 donors/patients with weakened A or B antigen expressions consisted of 4 cases of cis-AB/O (3 A(2)B(3), 1 A(2)B); 5 cases of cis-AB/A (5 A(1)B(x or el)); 2 cases of A/O (1 O, 1 A(m or x)); 1 case of B/O (1 B(m or x)); 4 cases of A/B (1 A(2)B , 1 A(1)B(x or el), 2 A(1)B(3)); and 2 cases of A(var)/B (2 A(w)B). On the other hand, the genotypes of 28 samples with unexpected serum reactions included 18 cases of A/O (16 A(1), 2 A(int)); 7 cases of A/A (5 A(1), 1 A(1)B(x or el), 1 A(1)B(w)); and 3 cases of O/O (1 O, 2 B(w)). ABO genotyping is useful for differentiating the ABO discrepancies that were difficult to resolve by serological tests. The most frequent unusual red cell reactions were weak A and B antigen expressions, which were resulted from the ABO subgroup alleles including cis-AB allele, whereas the most frequent unusual serum reactions were caused by decreased anti-B titers.

First two ABO‐incompatible living renal transplantations using splenectomy, rituximab, plasmapheresis and IVIG as a preconditioning regimen: a single center experience in the Balkans

Due to the growing organ shortage in the Balkans and still underdeveloped cadaver transplantation, we started accepting living expanded criteria renal donors including elderly, marginal and unrelated donors (spouses, etc). The ABO-incompatible renal transplantation was initiated last year. The first two successful cases are presented. A 40-yr-old mother (blood group A1B) and a 57-yr-old husband (blood group B) were considered as suitable donors for an 18-yr-old daughter (blood group B) and a 52-yr-old wife (blood group O). Both the recipients had a relatively long dialysis treatment before the surgery. The anti-A1 and anti-B titer of isoaglutinins was 1 : 64 in both the recipients before the procedure. A routine laparoscopic splenectomy was performed 40 and 45 days before the transplantation, without any complications. In the 10 days pre-conditioning period, rituximab was administered in a single dose of 375 mg/m2. At the same time four to five plasmaphereses were performed to reduce the isoaglutinins to below 1 : 4. On the last night before the surgery intravenous immunoglobulin (IVIG) in a dose of 0.5 g/kg/bw was administered. Standard induction and maintenance therapy was introduced (Dacllizumab, CyA-Neoral, MMF and steroids) according to the accepted policy in our transplant center. The routine plasmaphereses were performed in the first 2 weeks after transplantation to keep the isoaglutinins titer below 1 : 8. Ten and 6 months after the surgery both recipients are doing well. Their graft function remains stable (actual serum creatinin 140 and 230 microm/L, respectively). In the 1 month protocol biopsy a subclinical cellular and mild vascular rejection occurred, and both recipients were treated by steroid pulse therapy. One to two additional plasmaphereses were performed. The regularly monitored anti-A1 and anti-B isoaglutinins titer was kept below 1 : 8 during a period of follow-up. The first short-term results fully justify the ABO-incompatible living renal transplantation. The authors consider ABO-incompatible transplantation as a safe and promising procedure which may, together with expanded criteria living donors, ameliorate the actual donor shortage in the region.