Significance of prenatal joint detection of ABO antibody titers and irregular antibodies in pregnant women with type O blood

OBJECTIVE

To investigate the effects of blood transfusion and number of pregnancies on ABO antibody titers and irregular antibodies in pregnant women with type O blood.

MATERIALS AND METHODS

The study included 4,200 pregnant women with type O blood (their husbands were with non-O type blood) that were divided into transfusion group and non-transfusion group, according to whether they had a history of blood transfusion. The both groups were respectively divided into three subgroups (the number of pregnancies was one, two, and > or = three). The ABO antibody titers and irregular antibodies were detected at the same time. The effects ofABO antibody titers and irregular antibodies on hemolytic disease of the newborn (HDN) were discussed.

RESULTS

There was no consistency of ABO antibody titers and existence of irregular antibody. The positive rates of irregular antibody of transfusion group and of the subgroup (number of pregnancies > or = three) were far higher than that of non-transfusion group and of the subgroups (number of pregnancies < three), respectively. All pregnant women with positive irregular antibody in non-transfusion group were with HDN.

CONCLUSIONS

For pregnant women with number of pregnancies > or = three or with history of blood transfusion, the prenatal joint detection of ABO antibody titers and irregular antibodies is helpful for accurately reflecting the in vivo antibody type and level.

Anti-red blood cell antibodies, free light chains, and antiphospholipid antibodies in intravenous immunoglobulin preparations

BACKGROUND

Anti-red blood cell antibodies, free light chains (FLC) and prothrombotic proteins (PTP) may co-elute with intact immunoglobulin (IgG), and may be the cause of adverse reactions to intravenous immunoglobulin preparations (IVIG).

OBJECTIVES

To investigate the presence of residual amounts of these components in IVIG and their effects on ABO blood group agglutination.

METHODS

Iso-agglutinin anti-A and anti-B activity was determined with a direct hemagglutination assay of red blood cell (RBC) suspensions from 1% of 46 blood donors together with the serial dilutions of five IVIG (IV1, IV2, IV3, IV4, IV5). Anti-A1 monoclonal antibody was used to confirm reactivity with the A1-reference RBC. The selected IVIG were diluted to a final concentration of 25 mg/ml in 0.15 M NaCI and 0.01 M phosphate-buffered saline, pH 7.4, with or without a further twofold dilution in a low ionic strength solution.

RESULTS

A variation up to fivefold in the titer strength of anti-A/B activity was observed between the IVIG preparations. A2-type RBC required higher IVIG inputs when tested in 0.15 M NaCl. The differences in FLC kappa and lambda concentrations were as high as > 400 mg/L among the various IVIG. Only IV1 had a significantly high level of antiphospholipid IgG antibodies (18 U/ml). We demonstrated the presence of anti-RBC antibodies, FLC and PTP in IVIG preparations.

CONCLUSIONS

Our findings provide clear evidence that IVIG may harbor pathophysiological substrates with a potential risk for adverse effects such as iatrogenic hemolysis, FLC-associated disorders, and thromboembolism.

Cancer risk after ABO-incompatible living-donor kidney transplantation

BACKGROUND

Recipients of ABO-incompatible (ABOi) living-donor kidney transplants often undergo more intense immunosuppression than their ABO-compatible counterparts. It is unknown if this difference leads to higher cancer risk after transplantation. Single-center studies are too small and lack adequate duration of follow-up to answer this question.

METHODS

We identified 318 ABOi recipients in the Transplant Cancer Match Study, a national linkage between the Scientific Registry of Transplant Recipients and population-based U.S. cancer registries. Seven cancers (non-Hodgkin lymphoma, Merkel cell carcinoma, gastric adenocarcinoma, hepatocellular carcinoma, thyroid cancer, pancreatic cancer, and testicular cancer) were identified among ABOi recipients. We then matched ABOi recipients to ABO-compatible controls by age, gender, race, human leukocyte antigen mismatch, retransplantation, and transplant year.

RESULTS

There was no demonstrable association between ABOi and cancer in unadjusted (incidence rate ratio, 0.83; 95% confidence interval, 0.33-1.71; P=0.3) or matched control (incidence rate ratio, 0.99; 95% confidence interval, 0.38-2.23; P=0.5) analyses.

CONCLUSION

To the extent that could be determined in this registry study, current desensitization protocols are not associated with increased risk of cancer after transplantation.

Clinical features and risk factors of pure red cell aplasia following major ABO-incompatible allogeneic hematopoietic stem cell transplantation

The objective of this paper was to study the incidence, risk factors, clinical outcome, management and prevention of pure red cell aplasia (PRCA) following major ABO-incompatible allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed 11 cases of PRCA from a series of 42 patients undergoing major ABO-incompatible allo-HSCT from April 1997 to December 2005. Eleven out of the 42 patients developed PRCA (26.1%). All the 11 cases of PRCA were in blood group O recipients of grafts from blood group A donor (n = 9) or blood group B donor (n = 2). The following factors were associated with an increased risk of PRCA: (1) blood group O recipient; (2) blood group A donor; and (3) blood group O/A in recipient/donor pair. Only blood group O/A in recipient/donor pair was identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Six patients who received donor-type plasma exchange did not develop PRCA and among them 5 cases were the blood group O recipients. Eight patients obtained spontaneous remission and in the remaining 3 patients 2 with long-lasting PRCA were successfully treated with plasma exchange with donor-type plasma replacement and the other one who was also complicated by EBV-associated lymphoproliferative disorder (EBV-PTLD) responded rapidly to anti-CD20 monoclonal antibody and achieved complete resolution of clinical finding and symptom of both EBV-PTLD and PRCA. We conclude that blood group A/O in donor/recipient pair is identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Donor-type plasma exchange and anti-CD20 monoclonal antibody is an effective approach for the treatment of PRCA. PRCA could be prevented by plasma exchange prior to transplantation.

Impact of CD31 mismatches on the outcome of hematopoeitic stem cell transplant of HLA-identical sibling

Graft-versus host disease (GVHD) complicating allogeneic hematopoeitic stem cell transplantation (HSCT) is often attributed to mismatching of minor histocompatibility antigens (mHags), which are poorly defined in humans. CD31 is a candidate human mHag relevant to acute GVHD (aGVHD), but reports disagree about its level of significance. Therefore, we examined the impact of CD31-matching on the outcome of HSCT in different hematological and immunological diseases. About 60 patients receiving HSC from their respective HLA-ABCDR and DQ-identical sibling were studied. DNA was used to study the CD31 allele polymorphism at the codon 125 (LL, LV or VV) in the patient-donor pairs using the principle of allele-specific PCR amplification. Four primer were used; two primers (forward and reverse) for the L allele and another two for the V allele. The CD31 identity was tested for correlation with HSCT outcome measures of aGVHD, chronic GVHD, and relapse. The gene frequency of CD31 alleles (LL, VV and LV) was 28.3, 20 and 51.7%, respectively. CD31 identity was found in 31 pairs (51.7%) versus 29 pairs (48.3%) for nonidentity. The CD31 noncompatibility showed statistical non-significant relation with aGVHD (G 0-I, and G II-IV) and chronic GVHD (De-novo and chronic on acute) (p = 0.59, p = 0.62, p = 036 and p = 0.83, respectively). The CD31 nonidentity had statistical significant relation with aGVHD versus no aGVHD (p = 0.008 and OR = 4.46). The CD31 nonidentity showed statistical significant relation with aGVHD (II-IV) versus no aGVHD (p = 0.012 and OR = 7.14) and also, aGVHD (0-I) versus the no aGVHD (p = 0.03, OR = 3.13, respectively). A statistical significant relation was found between CD31 nonidentity in patient-donor pairs and relapse (p = 0.014 and OR = 4.21). In conclusion, the donor-recipient CD31 nonidentity is a significant risk factor for aGVHD and relapse in HLA-identical sibling.

[Time course of morphological changes in humoral renal allograft rejection in ABO incompatibility between donor and recipient]

One hundred and five biopsy specimens taken in different periods after 34 ABO-incompatible mismatched related kidney transplantations were examined to establish the patterns of humoral activity from the morphological changes and expression of C4d deposits in the peritubular capillaries. Severe reversible forms of acute humoral rejection (AHR) (2 patients) and minimal morphological manifestations (13 patients) were observed in the biopsy specimens taken as long as 2 months later in Group 1 (C4d+). In the early period, the minimal manifestations of AHR did not cause organ dysfunction; but in the late period, 5 of them developed chronic humoral rejection in persistent humoral activity; 4 grafts were removed 531,720, 1019, and 1252 days later. Group 2 (C4d-) (n = 19) showed no graft losses or significant chronic changes; the late minimal manifestations of AHR had no impact on the duration of organ function in 3 recipients. The timely detection of early humoral activity and minimal manifestations of AHR is needed for the measures taken to reduce a risk for late function loss of the grafted organ.

Maximising living donation with paediatric blood-group-incompatible renal transplantation

Long-term outcomes for paediatric renal transplant recipients have improved over the last 20 years, with better patient and renal allograft survival. As paediatric renal transplantation programmes have increased over this timeframe, living donation has become the favoured modality for renal replacement therapy and is advocated pre-emptively in as many cases as possible. However, one of the main barriers historically to living donation has been ABO blood-group incompatibility, with the result that patients were listed to be on call for a deceased donor renal transplant. The clinical scenario has now changed so that donors and recipients for renal transplantation can be worked up and listed for paired exchange and/or living-related ABO blood-group-incompatible renal transplantation (ABOi). There is extensive data in adult practice, and increasing evidence in paediatric practice that the short- and medium-term outcomes for both patient and renal allograft survival for ABOi is equivalent to that of blood-group-compatible renal transplantation.

[Identification and genotyping of difficult blood groups in the patients with phymatosis]

In part of the patients with blood disease or malignant tumors, especially those with leukemia and multiple myeloma, the disease state and unsuitable treatment often resulted in the inconsistence between positive and negative ABO blood group, displaying attenuation of the antigen or antibody of ABO blood group. This study was purposed to analyze the course of inconsistence between positive and negative ABO blood group and to perform the correct typing of erythrocytes and genes. The serology, absorption and elution test were used to examine the 12 tumor patient of the inconsistence between positive and negative typing. The 6th, 7th exon and 5-7th introns were amplified by PCR for questionable samples, and the gene sequencing of exon was performed. The results showed that 9 specimens were determined as 6 of A group, 2 of O group, 1 of B group, 3 cases were identified as O46, B108, and A102 group, respectively, by the serology, absorption and elution typing. The genotype of 2 cases among them was not identified because of the erroneous PCR amplified result or the contradicted sequencing results, failing to determine the ABO genotype. It is concluded that the serological method for blood grouping, genotyping, absorption and elution method can be used for the blood samples unable to typing because of the inconsistence between positive and negative typing of ABO group, therefore, guaranteeing the safety and effectiveness.

Changes in sex and non-sex hormones and distribution of erythrocyte antigens in reproductive age women with tumors of body of uterus in Adjara

The aim the research was to study the hormonal state of reproductive age women with tumors of body of uterus. The quantitative changes of sex steroid hormones: progesterone (P), estradiol (E), testosterone (T), gonadotropine -Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) were investigated. Distribution of ABO blood group antigens and Rh-Hr systems genetic variants in the blood of women living in Adjara Region was also studied. For study was used reproductive age women's blood with benign (fibromioma) and malignant (endometrial cancer) tumors of body of uterus (the middle age was 20-45 years). The determination of hormones was made by the enzymatic analysis method (ELAIZA). For the research of blood groups, were used the immunoserologic methods. The study have revealed that in blood of reproductive age women with benign and malignant tumors of body of uterus, level of estradiol was increased while levels of progesterone and testosterone were sharply reduced. Amount of Follicle-stimulating hormone and Luteinizing hormone were also increased. It's significant that, both hormones were sharply increased in case of cancer of body of uterus, in comparison with control group and benign tumor. According to distribution of ABO blood group phenotypes - O (I) phenotypic group of ABO system has its highest frequency in blood of women with cancer of body of uterus. Cancer of body of uterus is associated with O (I) phenotypic groups; benign tumor of body of uterus - with A(II) and AB(IV) phenotypic groups. Women with cc and EE genetic variants of Rh-Hr system have sensitivity to the development of benign and malignant tumors of body of uterus; women with ee genetic variant have lower sensitivity towards body of uterus cancer and sharply expressed sensitivity to uterus benign tumors. In women with malignant tumors of body of uterus the frequency of distribution of Rh-Hr system CC genetic variant was sharply reduced.

IgE production to α-gal is accompanied by elevated levels of specific IgG1 antibodies and low amounts of IgE to blood group B

IgE antibodies to gal-α-1,3-gal-β-1,4-GlcNAc (α-gal) can mediate a novel form of delayed anaphylaxis to red meat. Although IgG antibodies to α-gal (anti-α-gal or anti-Gal) are widely expressed in humans, IgE anti-α-gal is not. We explored the relationship between the IgG and IgE responses to both α-gal and the related blood group B antigen. Contradicting previous reports, antibodies to α-gal were found to be significantly less abundant in individuals with blood group B or AB. Importantly, we established a connection between IgE and IgG responses to α-gal: elevated titers of IgG anti-α-gal were found in IgE-positive subjects. In particular, proportionally more IgG1 anti-α-gal was found in IgE-positive subjects against a background of IgG2 production specific for α-gal. Thus, two types of immune response to α-gal epitopes can be distinguished: a ‘typical’ IgG2 response, presumably in response to gut bacteria, and an ‘atypical’, Th2-like response leading to IgG1 and IgE in addition to IgG2. These results suggest that IgE to a carbohydrate antigen can be formed (probably as part of a glycoprotein or glycolipid) even against a background of bacterial immune stimulation with essentially the same antigen.

[Kidney allotransplantation from the AB0-incompatible donors]

The experience of 28 kidney allotransplantations from the AB0-incompatible donors was analyzed. The comparative group consisted of 38 patients, who received the AB0-compatible organ. The results were assessed using the following parameters: renal function, morphology of the biopsy samples of the transplanted kidney and actuary survival of the recipients with functioning transplants in both groups. The comparative analysis showed no significant difference between the two groups, giving the right to consider the kidney allotransplantation from the AB0-incompatible donors safe and effective.

ABO-incompatible kidney transplantation: long-term outcomes

In the past 20 years, over 2,000 cases of ABO-incompatible living kidney transplantation (ABO-ILKT) have been performed in Japan, expanding the donor pool and overcoming the serious shortage of organ donors. Overall long-term outcomes (>20 years) have been excellent and almost identical to the outcomes of ABO-compatible living kidney transplantation (ABO-CLKT). In the last decade, ABO-ILKT has become accepted as a therapeutic alternative for end-stage renal failure. Recently, approximately 30% of all living donor kidney transplantations in Japan have been ABO-ILKT. In the 1990s, desensitization included preoperative plasmapheresis, splenectomy, and heavy immunosuppression that caused surgical and medical stress on patients and a higher cost than that needed for ABO-CLKT for the preoperative conditioning. However, since 2000, rituximab has replaced splenectomy making ABO-ILKT much easier. It is also less stressful for patients. In the last decade, outcomes have improved significantly and 5- and 10-year graft survival have reached 95% and 90%, respectively-identical to, or even better than outcomes of ABO-CLKT. Our current preconditioning includes plasmapheresis 0-2 times, rituximab injection, and regular immunosuppression. Neither intravenous immunoglobulin nor prophylactic plasmapheresis is used after transplantation. ABO-ILKT is a standard option for kidney transplantation requiring minimal preconditioning and regular immunosuppression after transplantation. It now provides an excellent long-term (>20 years) outcome.

Anti-H can trigger apoptosis and down-regulate FUT1 expression in erythroid differentiated K562 cells without complement mediation

The reason why delayed RBC engraftment and pure red cell aplasia (PRCA) develop only in some but not all recipients of major ABO-incompatible hematopoietic stem cell transplantation (HSCT) remains elusive and the underlying mechanisms are not fully understood. Understanding how incompatible erythroid blood group antibodies (Abs) interact with ABH antigens (Ags) of grafts, and investigating how to induce artificially accommodation of grafts are of obvious importance in transplantation immunology. The effects of anti-H on proliferation, apoptosis, and α-(1,2)-fucosyltransferase gene (FUT1) expression in erythroid differentiated K562 cells were analyzed by the MTT assay, Annexin V/PI staining, and quantitative RT-PCR method. The growth of erythroid differentiated K562 cells was significantly suppressed when anti-H dilution was ≤ 1:8 (P<0.001, as compared with 1:16). Under the complement-free culture conditions, the apoptotic ratio of erythroid differentiated K562 cells was significantly increased when anti-H dilution was ≤ 1:16 (P<0.05, as compared with 1:32). The apoptosis was not only closely associated with anti-H dilution (F=138.991, P<0.001), but also correlated with treated time (F=583.249, P<0.001), which indicated typical dose- and time-dependent effects. Under the complement-free culture conditions, the FUT1 mRNA expression level was also suppressed when anti-H dilution was ≤ 1:16 (P<0.05, as compared with 1:32), which also manifested in typical dose-dependent (F=130.356, P<0.001) and time-dependent (F=1432.00, P<0.001) effects. The results confirm that anti-H can trigger apoptosis and down-regulate FUT1 expression in erythroid differentiated K562 cells without complement mediation. The findings suggest that anti-H could accommodate grafts through triggering apoptosis and down-regulating Fut1 expression to reduce ABH antigens.

Incidence and pattern of hemolytic anemia after minor ABO-mismatched living-donor lobar lung transplantation

PURPOSE

Living-donor lobar lung transplantation (LDLLT) has been successfully performed in Japan. In LDLLT, the recipient usually receives one lower lobe from each of two donors; however, finding two ABO-matched donors is often difficult. Solid organ transplants from donors with minor ABO-mismatches can be complicated by hemolysis. We investigated the incidence of de novo anti-ABO antibody production and hemolysis in patients receiving LDLLT across minor ABO-mismatches.

METHODS

We evaluated 23 patients who underwent LDLLT between June 2008 and December 2011, including 11 patients who underwent minor ABO-mismatched transplantation. We measured the anti-A/B antibody serum titers, hemoglobin concentrations and indirect bilirubin levels.

RESULTS

None of the patients showed any clinical signs of hemolytic anemia (mean follow-up period; 16 months). Two of the 11 patients (18 %) receiving minor ABO-mismatched LDLLTs showed a small amount of de novo anti-B antibodies for a transient period. These patients showed gradual progression of anemia, and weak de novo anti-A/B antibodies were detected with column agglutination technology. The patients received only 2 U of washed type O red blood cells; thereafter, the hemolytic anemia did not develop further in either case.

CONCLUSION

LDLLT across minor ABO-mismatches results in the transient appearance of weak de novo anti-A/B antibodies with a low incidence; thus, this procedure can be a safe treatment.

New Zealand's first two-pair kidney transplant chain

Kidney transplantation is the treatment of choice for end-stage renal disease, providing better quality and quantity of life compared with dialysis. Living donor transplantation is being increasingly utilised to match the demand, however it is limited by HLA antigens or ABO blood group incompatibility between the donor and recipient. Organising a kidney transplant chain can overcome such incompatibilities through recipients 'exchanging' incompatible for compatible donors. We have reported New Zealand's first two-pair kidney transplant chain, outlining the reasons for this new technique, its benefits and some of its limitations.

ABO blood groups influence macrophage-mediated phagocytosis of Plasmodium falciparum-infected erythrocytes

Erythrocyte polymorphisms associated with a survival advantage to Plasmodium falciparum infection have undergone positive selection. There is a predominance of blood group O in malaria-endemic regions, and several lines of evidence suggest that ABO blood groups may influence the outcome of P. falciparum infection. Based on the hypothesis that enhanced innate clearance of infected polymorphic erythrocytes is associated with protection from severe malaria, we investigated whether P. falciparum-infected O erythrocytes are more efficiently cleared by macrophages than infected A and B erythrocytes. We show that human macrophages in vitro and mouse monocytes in vivo phagocytose P. falciparum-infected O erythrocytes more avidly than infected A and B erythrocytes and that uptake is associated with increased hemichrome deposition and high molecular weight band 3 aggregates in infected O erythrocytes. Using infected A₁, A₂, and O erythrocytes, we demonstrate an inverse association of phagocytic capacity with the amount of A antigen on the surface of infected erythrocytes. Finally, we report that enzymatic conversion of B erythrocytes to type as O before infection significantly enhances their uptake by macrophages to observed level comparable to that with infected O wild-type erythrocytes. These data provide the first evidence that ABO blood group antigens influence macrophage clearance of P. falciparum-infected erythrocytes and suggest an additional mechanism by which blood group O may confer resistance to severe malaria.

Plasmodium falciparum malaria is considered to be one of the strongest forces for evolutionary selection pressure on the human genome. Different red blood cell variants associated with a survival advantage to P. falciparum infection have undergone positive selection. Blood group O is found more frequently in malaria-endemic regions and has been associated with protection against severe malaria and death. However the biological basis of protection remains unclear. In this study, we investigated innate immune clearance of P. falciparum-infected erythrocytes by macrophages as a possible mode of protection. We show that macrophages clear P. falciparum-infected O erythrocytes more avidly than infected A and B erythrocytes. We also report that enzymatic conversion of infected blood group B red cells to type as “O” like erythrocytes significantly enhances their uptake by macrophages to a level comparable to that observed with infected O wild type erythrocytes. These data provide the first evidence that clearance of P. falciparum-infected erythrocytes is influenced by human ABO blood groups and suggest a new mechanism by which blood group O may contribute to protection against severe malaria.

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

BACKGROUND

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.

STUDY DESIGN AND METHODS

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.

RESULTS

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%).

CONCLUSION

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.

Relationship between ABO blood group and ABH secretor status in Kano, north-western Nigeria

BACKGROUND

The determination of ABO Blood groups and ABH secretor status in blood and body fluid antigens respectively may have certain structural and disease related genetic linkages, hence the need to establish relationship between blood group and secretor status in the population.

METHOD

A total of 256 subjects comprised of blood donors and healthy pregnant women at Aminu Kano Teaching Hospital, Kano were studied. Their ABO Blood groups and secretor status were determined by standard tile/tube and haemaglutination inhibition methods respectively.

RESULTS

The result of this study shows that blood group B had the highest percentage ofsecretors (85.33%) followed by blood group AB (83.33%). Blood group O had a value of 64.18% while blood group A had the lowest prevalence of secretors of 61.9% in Kano metropolis.

CONCLUSION

Blood groups A and O have lower prevalence of secretors compared to blood group B and AB, in Kano metropolis. There is need for further study to identify risk predisposition of these groups to cancer of the stomach and duodenal ulcer disease respectively; as reported in other parts of the world.

No red cell alloimmunization or change of clinical outcome after using fresh frozen cancellous allograft bone for acetabular reconstruction in revision hip arthroplasty: a follow up study

BACKGROUND

Possible immunization to blood group or other antigens and subsequent inhibition of remodeling or incorporation after use of untreated human bone allograft was described previously. This study presents the immunological, clinical and radiological results of 30 patients with acetabular revisions using fresh frozen non-irradiated bone allograft.

METHODS

AB0-incompatible (donor-recipient) bone transplantation was performed in 22 cases, Rh(D) incompatible transplantation in 6 cases. The mean follow up of 23 months included measuring Harris hip score and radiological examination with evaluation of remodeling of the bone graft, implant migration and heterotopic ossification. In addition, all patients were screened for alloimmunization to Rh blood group antigens.

RESULTS

Compared to the whole study group, there were no differences in clinical or radiological measurements for the groups with AB0- or Rh(D)-incompatible bone transplantation. The mean Harris Hip Score was 80.6. X-rays confirmed total remodeling of all allografts with no acetabular loosening. At follow up, blood tests revealed no alloimmunization to Rh blood group donor antigens.

CONCLUSIONS

The use of fresh frozen non-irradiated bone allograft in acetabular revision is a reliable supplement to reconstruction. The risk of alloimmunization to donor-blood group antigens after AB0- or Rh-incompatible allograft transplantation with a negative long-term influence on bone-remodeling or the clinical outcome is negligible.

Serological characteristic and molecular basis of A2 subgroup in the Chinese population

BACKGROUND

A2 phenotype is a common subgroup of blood group A, but the serological characteristic and genetics basis of A2 phenotype currently was rare reported in the Chinese Han population. Here, a large scale study of the serology and genetics of A2 and A2B phenotypes was performed.

METHODS/MATERIALS

11263 Chinese individuals with group A and AB phenotypes were determined for A2 antigen with the standard serological method. The full coding region of the ABO gene was sequenced in the individuals with A2 and A2B phenotypes. Some samples including each ABO genotypes were chosen for determining the activity of glycosyltransferase A (GTA) in plasma.

RESULTS

134 individuals were assigned as A2 and A2B phenotypes in 11263 individuals. There was imbalance in A2 and A2B phenotypes and the proportion of A2B among AB samples was significantly higher than that of A2 in group A samples. All samples of the A2 and A2B phenotypes were classified into A2-related allele group, A1-related allele group and the other group based on kind of the ABO genotype. Four novel A2-related alleles (A217, A218, A219, A220) were identified. The individuals with same genotype showed different agglutination strength with anti-A1 and anti-H on their RBCs. The plasma from individuals with A2-related allele had almost no GTA activity, while plasma from individuals with A1-related allele had some GTA activity.

CONCLUSION

A2 and A2B phenotypes could derive from different genotypes and the serological characteristic may be heterogeneity in the Chinese Han population.

Transfusion medicine problems and solutions for the pediatric hematologist/oncologist

Blood component transfusion is an integral part of the care of children with oncologic and hematologic conditions. The complexity of transfusion medicine may however lead to challenges for pediatric hematologists/oncologists. In this review, three commonly encountered areas of transfusion medicine are explored. The approach to the investigation and management of suspected platelet refractoriness is reviewed. The unique transfusion related challenges encountered by children undergoing stem cell transplantation are also discussed. Finally, issues arising out of the care of children with hemoglobinopathies are explored, with an emphasis on the incidence of allo- and autoimmunization.

[ABO incompatible renal transplantation]

ABO-incompatible living donor renal transplantation began in 1982. It may provide a significant source of organs. One dose of rituximab is given four weeks pre-operatively and oral triple immunosuppressive regimen is introduced 7 days pre-operatively. Anti A/B titres are lowered to less than 1:8 by specific immunoadsorption with Glycosorb column. During the first 15 days post-transplant, accommodation state is acquired. Thereafter, graft and patient survivals, and acute humoral rejection rates are the same as those of ABO identical renal transplantations.

Morbidity of ABO haemolytic disease in the newborn

BACKGROUND

Better understanding of the clinical characteristics of ABO haemolytic disease in neonates helps optimise care.

OBJECTIVE

To assess the morbidity associated with maternal-neonatal ABO incompatibility.

METHODS

Neonates with blood groups A or B born to mothers with blood group O with simultaneous rhesus blood factor compatibility were studied prospectively. Maternal and neonatal details, direct Coomb's test (DCT) on the cord blood, onset and progression of jaundice, and requirement and duration of phototherapy were studied. Neonates requiring phototherapy were considered to have significant hyperbilirubinaemia, and peripheral smear, reticulocyte count and haematocrit values were obtained. ABO haemolytic disease of the newborn (ABO HDN) is defined as a newborn with a positive DCT and/or laboratory evidence of haemolysis such as reticulocytosis and spherocytes on blood smear.

RESULTS

Of 878 deliveries, 151 (17.3%) neonates were ABO incompatible with their mothers. The proportions who were O-A and O-B incompatible were 50.4% and 49.6%, respectively. Forty-six (30.4%) had significant hyperbilirubinaemia (119.7-256.5 mmol/L) and required phototherapy, 26 (34.2%) of them in the O-A group and 20 (26.6%) in the O-B group. None required exchange transfusion. Jaundice was detected within the first 24 hours in 47.8%. Of 46 newborns who required phototherapy, 25 (54.3%) had laboratory evidence of haemolysis. DCT was positive in 1.9% of ABO-incompatible newborns. There was no significant difference in the incidence and severity of haemolysis between the O-A and O-B-incompatible neonates. Neonates with haemolysis required phototherapy significantly earlier and for longer than neonates without haemolysis (P<0.001).

CONCLUSIONS

ABO incompatibility was observed in 17.3% of pregnancies with almost equal O-A and O-B frequency. About a third of infants had significant hyperbilirubinaemia. There was no difference in severity between those with O-A and O-B HDN.

The efficacy of EBER in situ hybridization (ISH) stain in PTLD (malignant diffuse large B-cell lymphoma) about 4 years after ABO-incompatible kidney transplantation: a case report

Post-transplant lymphoproliferative disease (PTLD) is a well-known late complication of organ transplantation which incidence has increased after the introduction of more powerful immunosuppressive agents. A 58-year-old man performed ABO-incompatible living kidney transplantation in June, 2008. At 3 years and 9 months after the transplantation, the patient complained of general fatigue and dyspnea and was hospitalized with renal dysfunction. The clinical data in hospital showed acute rejection, but soluble IL-II exceeded 21700U/ml, and HE staining kidney graft showed a massive infiltration of atypical lymphocytes. Atypical lymphocytes were positive for L-26 and negative for CD3 immunochemical stein, and the EBER in situ hybridization stain for EBV was negative in renal graft. We diagnosed diffuse large B-cell lymphoma in the kidney graft. However, he died due to multiple organ failure (MOF). We described a fatal case of diffuse large B-cell lymphoma without EBV infection occurring 3 years 9 months after ABO-incompatible kidney transplantation. Unfortunately, post-mortem autopsy using EBER-ISH stain does not show whether EB virus infection was a cause.

State of pediatric kidney transplantation in 2011

Fifty years ago children with renal failure died due to the lack of adequate therapy. Today, the implementation of dialysis procedures, such as peritoneal dialysis and hemodialysis as well as kidney transplantation, has become almost standard care for pediatric patients. Even infants can now be dialyzed or receive transplants. A kidney transplant allows for a 20-year patient survival in >90% of patients and almost age-appropriate mental and physical development. A better transplant survival is achieved with a living organ donation than with a post-mortem donation. It has been shown that kidneys from deceased juvenile and young adult donors should be allocated primarily to children as they obtain significantly better transplant function in the short and medium term than adults. Unfortunately, the problem of a long waiting period for a postmortem donated kidneys for children in the Eurotransplant area remains. Although, the allocation system for children was amended in December 2010, it remains to be seen whether this change will positively influence waiting times. New immunosuppressive regimens have resulted in significantly improved long-term transplant function and transplant survival. The main challenge, however, concerns chronic humoral transplant rejection, therapy for recurrence of the underlying disease, and the execution of AB0 incompatible transplantations.

Outcomes of ABO-incompatible kidney transplantation in the United States

BACKGROUND

ABO incompatible (ABOi) kidney transplantation is an important modality to facilitate living donor transplant for incompatible pairs. To date, reports of the outcomes from this practice in the United States have been limited to single-center studies.

METHODS

Using the Scientific Registry of Transplant Recipients, we identified 738 patients who underwent live-donor ABOi kidney transplantation between January 1, 1995, and March 31, 2010. These were compared with matched controls that underwent ABO compatible live-donor kidney transplantation. Subgroup analyses among ABOi recipients were performed according to donor blood type, recipient blood type, and transplant center ABOi volume.

RESULTS

When compared with ABO compatible-matched controls, long-term patient survival of ABOi recipients was not significantly different between the cohorts (P=0.2). However, graft loss was significantly higher, particularly in the first 14 days posttransplant (subhazard ratio, 2.34; 95% confidence interval, 1.43-3.84; P=0.001), with little to no difference beyond day 14 (subhazard ratio, 1.28; 95% confidence interval, 0.99-1.54; P=0.058). In subgroup analyses among ABOi recipients, no differences in survival were seen by donor blood type, recipient blood type, or transplant center ABOi volume.

CONCLUSIONS

These results support the use and dissemination of ABOi transplantation when a compatible live donor is not available, but caution that the highest period of risk is immediately posttransplant.

Erythrocyte group antigens and women's reproductive system organs

The aim of this study is to investigate the presence of a possible association between breast and uterus cancer with blood ABO groups in women of reproductive, menopausal and post-menopausal age. Following information was recorded: patient age, stage of cancer, ABO blood group. In diseased population (120 subject) was investigated for ABO red cell blood groups antigens. Immunoserological methods have been used to identify the antigens. The obtained results were statistically processed. High frequency of A antigen is found in uterus cancer diseased, on the thirst stage, in the reproduction age (65±10,6%). High frequency of O antigen was found on the first stage, of the aid in the post-reproductive (55±11,1%) and in the postmenopausal periods (60±10,9%). ABO blood group antigens have been studied in breast cancer diseased, on the second and third stages, postmenopausal women, in which high frequency of A antigen is found.

Outcomes after major or bidirectional ABO-mismatched allogeneic hematopoietic progenitor cell transplantation after pretransplant isoagglutinin reduction with donor-type secretor plasma with or without plasma exchange

BACKGROUND

Major ABO mismatch in hematopoietic progenitor cell transplantation (HPCT) is associated with a range of immunohematologic consequences including progenitor cell infusion (PCI)-related hemolysis, delayed red blood cell engraftment, and pure red cell aplasia (PRCA). Although pretransplant (recipient) isoagglutinin reduction may be associated with decreased immunohematologic complications in this setting, there is no consensus with respect to strategies for isoagglutinin reduction.

STUDY DESIGN AND METHODS

This observational study assessed the efficacy of a standardized pretransplant isoagglutinin reduction strategy incorporating donor-type secretor plasma infusions with or without plasma exchange to prevent PCI-associated hemolysis and PRCA in major or bidirectional ABO-mismatched peripheral blood HPCT. All major or bidirectional ABO-mismatched HPCTs performed between 1999 and 2010 were identified from an institutional database. Immunohematologic outcomes were determined retrospectively by review of individual medical records.

RESULTS

In total 110 major or bidirectional ABO-mismatched HPCTs had been performed. No patient developed hemolysis after PCI. With respect to PRCA incidence, 16 patients (15%) were excluded due to early mortality and three (3%) due to incomplete data; of the remaining 91 patients, five (5%) developed PRCA. Patients with PRCA had significantly higher pretransplant isoagglutinin titers (p = 0.0001) compared to those who did not develop PRCA.

CONCLUSIONS

Use of a standardized pretransplant isoagglutinin reduction strategy including donor-type secretor plasma infusions is both safe and efficient in preventing PCI-associated hemolysis and is associated with low rates of posttransplant PRCA.

[Apheresis in ABO-incompatible kidney transplant]

Living donor kidney transplantation is the preferred therapeutic option for patients with end stage renal disease. Unfortunately, about 20-30% of potential living kidney donors are rejected because of incompatible immunological barriers such as ABO incompatibility. The newest desensitization protocols based on therapeutic apheresis and perioperative immunosuppressive drugs have allowed to overcome antibody barriers. The aim of these protocols is to wash out and suppress as many anti-A or anti-B antibodies as possible and to prevent rebound phenomena after transplantation. Standard plasmapheresis, double-filtration plasmapheresis, and selective immunoadsorption are among the most common apheresis modalities applied in ABO-incompatible transplantation. Selective immunoadsorption appears to be much safer and to have markedly increased efficacy compared with plasmapheresis, as it eliminates almost exclusively blood-group antibodies, thus avoiding plasma and coagulation abnormalities. According to the literature, long-term patient and graft survival rates are similar to those achieved with ABO-compatible kidney transplants. We have used selective immunoadsorption in two ABO-incompatible kidney transplants performed at our institution. No acute rejection was observed at 12 and 32 months' follow-up and both grafts are functioning well. Despite the widespread use of ABO-incompatible kidney transplant, however, the mechanisms of accommodation, the best desensitization protocol, the upper baseline and perioperative isoagglutinin titer limit, and the most accurate isoagglutinin measurement assay are still to be defined.

[The kidney transplantation from the ABO-incompatible donors]

The experience of 28 allotransplantations of ABO-incompatible kidneys was compared with the treatment results of 38 ABO-compatible renal transplantations. The transplanted kidney function, morphological changes of the transplanted kidney and the comparative analysis of actuary survival in both groups showed no significant difference. The results of the study prove the validity of the kidney transplantation from the ABO-incompatible donors.

Seroprevalence of unexpected red blood cell antibodies among pregnant women in Uganda

We conducted a population-based, cross-sectional study among pregnant women in Kampala, Uganda, to determine ABO and D blood types and to determine the percentage who have unexpected red blood cell (RBC) antibodies and their specificities. De-identified blood samples from routine testing of 1001 pregnant women at the Mulago Hospital antenatal clinics in Kampala were typed for ABO and D and screened for the presence of unexpected RBC antibodies with confirmation and subsequent antibody identification. Of the 1001 blood samples tested, 48.9 percent, 26.4 percent, 21.0 percent, and 3.8 percent tested positive for blood groups 0, A, B, and AB, respectively. Of these samples, 23 (2.3%)were negative forD, and 55 (5.5%) showed initial reactivity with at least one screening RBC. The RBC antibody screen was repeated on these 55 samples, and antibody identification was performed at the Johns Hopkins Hospital Blood Bank in Baltimore, Maryland. Twenty-one of the 55 samples were confirmed to have evidence of agglutination. Nine of the 21 samples demonstrated the presence of clinically significant RBC antibodies with anti-S being the most common, 8 samples demonstrated the presence of benign or naturally occurring antibodies, and 4 had only inconclusive reactivity. This study revealed a relatively high frequency of D and a low frequency of demonstrable clinically significant alloantibodies that may cause hemolytic disease of the newborn or hemolytic transfusion reactions among pregnant women in Kampala, with anti-S being the most frequent antibody specificity.

Comparison of printed glycan array, suspension array and ELISA in the detection of human anti-glycan antibodies

Anti-glycan antibodies represent a vast and yet insufficiently investigated subpopulation of naturally occurring and adaptive antibodies in humans. Recently, a variety of glycan-based microarrays emerged, allowing high-throughput profiling of a large repertoire of antibodies. As there are no direct approaches for comparison and evaluation of multi-glycan assays we compared three glycan-based immunoassays, namely printed glycan array (PGA), fluorescent microsphere-based suspension array (SA) and ELISA for their efficacy and selectivity in profiling anti-glycan antibodies in a cohort of 48 patients with and without ovarian cancer. The ABO blood group glycan antigens were selected as well recognized ligands for sensitivity and specificity assessments. As another ligand we selected P(1), a member of the P blood group system recently identified by PGA as a potential ovarian cancer biomarker. All three glyco-immunoassays reflected the known ABO blood groups with high performance. In contrast, anti-P(1) antibody binding profiles displayed much lower concordance. Whilst anti-P(1) antibody levels between benign controls and ovarian cancer patients were significantly discriminated using PGA (p=0.004), we got only similar results using SA (p=0.03) but not for ELISA. Our findings demonstrate that whilst assays were largely positively correlated, each presents unique characteristic features and should be validated by an independent patient cohort rather than another array technique. The variety between methods presumably reflects the differences in glycan presentation and the antigen/antibody ratio, assay conditions and detection technique. This indicates that the glycan-antibody interaction of interest has to guide the assay selection.

Anti-A/B antibody depletion by semiselective versus ABO blood group-specific immunoadsorption

BACKGROUND

Recipient desensitization using blood group (BG)-specific immunoadsorption (ABO-IA) has proven to enable successful kidney transplantation across major ABO barriers. In this context, the efficiency of non-antigen-specific (semiselective) IA adsorbers has not yet been established. The objective of our study was to quantify anti-A/B antibody depletion by protein A-, peptide ligand- and anti-human immunoglobulin-based semiselective IA in comparison to ABO-IA.

METHODS

Eight ABO-IA-treated transplant candidates and 39 patients subjected to semiselective IA for a variety of different indications outside the context of ABO-incompatible transplantation were included. Antibody patterns (IgG, IgG1-4 subclasses, IgM, C4d-fixing reactivities) were analysed applying conventional agglutination testing and flow cytometry.

RESULTS

As assessed by sensitive flow cytometric antibody detection, ABO-IA-based desensitization led to a profound even though often incomplete reduction of anti-A/B reactivities. Persistent complement- or non-complement-fixing reactivities, however, were not associated with transplant rejection or capillary C4d deposition. Single sessions of semiselective IA turned out to be more effective than ABO-IA in decreasing levels of anti-A/B IgG [median reduction to 28 versus 59% (ABO-IA) of baseline values, P < 0.001). In contrast, BG-specific IgM (74 versus 30%, P < 0.001) and IgG3 (72 versus 42%, P < 0.05) were reduced to a lesser extent, without differences between tested adsorber types. Analysis of four consecutive IA sessions revealed that inferior efficiency could not be overcome by serial treatment.

CONCLUSION

Our observation of limited adsorption capacities regarding distinct BG-specific Ig (sub)classes suggests caution in applying semiselective IA techniques in ABO-incompatible kidney transplantation.

FUT2 nonsecretor status links type 1 diabetes susceptibility and resistance to infection

OBJECTIVE

FUT2 encodes the α(1,2) fucosyltransferase that determines blood group secretor status. Homozygotes (A/A) for the common nonsense mutation rs601338A>G (W143X) are nonsecretors and are unable to express histo-blood group antigens in secretions and on mucosal surfaces. This mutation has been reported to provide resistance to Norovirus and susceptibility to Crohn's disease, and hence we aimed to determine if it also affects risk of type 1 diabetes.

RESEARCH DESIGN AND METHODS

rs601338A>G was genotyped in 8,344 patients with type 1 diabetes, 10,008 control subjects, and 3,360 type 1 diabetic families. Logistic regression models were used to analyze the case-control collection, and conditional logistic regression was used to analyze the family collection. RESULTS The nonsecretor A/A genotype of rs601338A>G was found to confer susceptibility to type 1 diabetes in both the case-control and family collections (odds ratio for AA 1.29 [95% CI 1.20-1.37] and relative risk for AA 1.22 [95% CI = 1.12-1.32]; combined P = 4.3 × 10(-18)), based on a recessive effects model.

CONCLUSIONS

Our findings linking FUT2 and type 1 diabetes highlight the intriguing relationship between host resistance to infections and susceptibility to autoimmune disease.

[Peripheral blood stem cell collection from ABO incompatible allogeneic donors and its effect in hematopoietic stem cell transplantation]

The study was aimed to evaluate the yield of the COBE Spectra blood cell separator with auto-peripheral blood stem cell program for collection of peripheral blood hematopoietic stem cells (PBHSC) from HLA-matched ABO-incompatible allogeneic PBHSC donor, and observe the safety and effect of allogeneic peripheral blood hematopoietic stem cell transplantation (allo-PBHSCT) without removal of erythrocytes and plasma. PBHSC from 28 allogeneic donors were collected by COBE Spectra blood cell separator with auto-peripheral blood hematopoiEtic stem cell (auto-PBHSCT) program. Control group included 15 HLA-matched patients who received allo-PBHSCT with ABO-compatible grafts. The amount of PBHSC was harvested and the parameter was modified according to the hematocrit and mononuclear cell (MNC) counts of donors. The nucleated cell count, proportion of MNC, number of CD34(+) cells were detected, and reconstitution status of hematopoietic function and time for change into donor's blood group were observed. The results showed that the nucleated cell count proportion of MNC and number of CD34(+) cells showed no significant difference between groups of ABO incompatible and compatible (p > 0.05). All their hematopoietic functions were reconstituted. Between the ABO incompatibility and the compatible groups, the time of neutrophil and platelet recovery was not significantly different (p > 0.05), In ABO blood major incompatible and the compatible groups, the recovery of erythropoiesis were significantly delayed (p < 0.01). The blood type of 18 patients in ABO incompatible group was turned into donor's blood type successfully at 35-139 days after transplantation. It is concluded that major ABO incompatibility did not affect the erythropoiesis reconstitution in HLA matched allo-HSCT. the major incompatibility may be a main reason of erythropoietic delay.

Significance of complement split product C4d in ABO-compatible liver allograft: diagnosing utility in acute antibody mediated rejection

Diagnosis of liver allograft antibody-mediated rejection (AMR) is difficult and requires a constellation of clinical, laboratory and histologic features that support the disease and exclude other causes. Histologic features of AMR may intermix with those of biliary obstruction, preservation/reperfusion injury, and graft ischemia. Tissue examination for complement degradation product 4d (C4d) has been proved to support this diagnosis in other allografts. For this reason, we conducted a retrospective review of all ABO compatible/identical re-transplanted liver patients with primary focus on identifying AMR as a possible cause of graft failure and to investigate the utility of C4d in liver allograft specimens. We reviewed 193 liver samples obtained from 53 consecutive ABO-compatible re-transplant patients. 142 specimens were stained with C4d. Anti-donor antibody screening and identification was determined by Luminex100 flow cytometry. For the study analysis, patients were stratified into 3 groups according to time to graft failure: group A, patients with graft failure within 0-7 days (n=7), group B within 8-90 days (n=13) and C >90 days (n=33). Two patients (3.7%) met the diagnostic criteria of acute AMR. Both patients experienced rapid decline of graft function with presence of donor specific antibodies (DSA), morphologic evidence of humoral rejection and C4d deposition in liver specimens. C4d-positive staining was identified in different medical liver conditions i.e., acute cellular rejection (52%), chronic ductopenic rejection (50%), recurrent liver disease (48%), preservation injury (18%), and hepatic necrosis (54%). Univariate analysis showed no significant difference of C4d-positive staining among the 3 patients groups, or patients with DSA (P>.05). In conclusion, AMR after ABO-compatible liver transplantation is an uncommon cause of graft failure. Unlike other solid organ allografts, C4d-positive staining is not a rugged indicator of humoral rejection, thus, interpretation should be done with caution to avoid diagnostic dilemmas.

Incidence and risk factors for the development of prolonged severe intrahepatic cholestasis after pediatric living-donor liver transplantation

The aim of this study is to evaluate the incidence, etiology, and risk facrors for prolonged severe intrahepatic cholestasis (PSIC) after 129 pediatric living-donor liver transplantations (LDLT). The incidence of PSIC was 25.6% (n = 33). Twenty-eight (84.8%) versus 5 (15.2%) children experienced early versus late PSIC, respectively. Among these 33 children with PSIC, 8 (24.2%) received a donor liver with mild to moderate fatty change, 4 (12.1%) with low graft-body weight ratios, and 4 (12.1%) with ABO incompatibility. The predominant etiologies were acute rejection (n = 15; 45.5%), chronic rejection (n = 6; 18.2%), virus (n = 3; 9.1%), vascular complications (n = 4; 12.1%), and initial graft dysfunction (n = 10; 30.3%). ABO incompatibility (P = .032; odds ratio [OR] 3.25), chronic rejection (P = .012; OR 4.76), and vascular complications (P = .046; OR 1.82) were significant variables associated with PSIC. Donor selection with ABO compatibility as well as early detection and management of chronic rejection and vascular complications may be important to prevet PSIC in LDLT.

Subgrouping of A and AB blood groups in Indian blood centres: is it required?

Anti A1 antibody in the serum of A2 and A2B individuals is rare but when present can have laboratory and clinical significance. Routine subgrouping of all A and AB blood groups in blood centres in India is difficult due to economic constraints and has always been a point of debate. This study thus brings out the prevalence of anti A1 antibody and the clinical significance related to its presence. The results of the study showed a low prevalence of anti A1 antibody and when present, it had a low thermal amplitude and titre. Further, no blood group discrepancy or problems during compatibility testing were encountered with these (A1 antibody positive) blood units. Thus, it may be concluded that in India and other developing countries where resources are scarce, routine subgrouping of A and AB may not be really worthwhile unless there is a group discrepancy, problem during compatibility testing or history of a transfusion reaction.

[Errors in the AB0-blood group determination as a cause of hemolytic complications after incompatible hemotransfusion]

According to literature data and results of own investigations there was established, that the causes of frequent mistakes occurrence while performing the blood investigation, causing hemolytic complications, are the blood groups antigens determination according to AB0 system using the direct method only, without isohemoagglutinins alpha, beta identification; constitutes the direct transduction of written information from medical and other documentation or immediately from the speaking patient.

[Kidney transplantation from an ABO-incompatible living donor]

Living donor kidney transplantation is the preferred therapeutic option for patients with end stage renal disease because it provides a superior immunological compatibility, it lessens the preservation-mediated graft injury and it shortens waiting time on dialysis. Unfortunately, about 30-35% of potential living kidney donors are rejected because of incompatible immunological barriers such as ABO-incompatibility or a positive crossmatch. The newest desensitization protocols based on both therapeutic apheresis and perioperative immunosuppressive drugs allowed to overcome antibodies barriers. The aim of those protocols is to wash-out and suppress as much anti-A or anti-B antibodies as possible and to prevent the rebound phenomena after transplantation. Standard plasmapheresis, double-filtration plasmapheresis and selective immunoadsorption are among the most common apheretic modalities applied in ABO-incompatible transplantation. Furthermore, selective immunoadsorption appears to be much safer and to have markedly increased efficacy comparing with plasmapheresis being able to eliminate almost exclusively blood-group antibodies avoiding plasma and coagulation abnormalities. According to literature, long-term patient and graft survival rates are similar to those achieved by ABO-compatible kidney transplants. The comparable outcome seems related to more effective desensitization protocols as well as the protective immune mechanisms of "accommodation". We have been using selective immunoadsorption in the two ABO-incompatible kidney transplants performed in our institution. No acute rejection was experienced at 6 and 26 month follow-up and both grafts are functioning well. Despite the ABO-incompatible kidney transplant widespread use, the best desensitization protocol, the upper baseline and perioperative isoagglutinin titer limit and the most accurate isoagglutinin measurement assay are still to define.

[C742T mutation of α1, 3 N-acetyl-D-galactosaminyltransferase gene is responsible for A2 subgroup]

The objective of this study was to analyze the molecular genetic basis for 2 individuals with A2B phenotype of ABO subtype. The ABO group antigens on red blood cells were identified by monoclonal antibodies and the ABO antibodies in serum were detected by the standard A, B, O cells. The exon 5 to exon 7 coding region of ABO gene was amplified by polymerase chain reaction (PCR) and the PCR product was sequenced directly after the enzymes digested. The amplified product was also cloned by TOPO TA cloning sequencing kit to split the 2 alleles apart and chosen colonies were sequencing bidirectionally for exon 6 to 7 of ABO gene. The results showed that both A and B antigen were identified on red blood cells of the individuals and there was anti-A1 antibody in their serum. There was no 261G deletion and showed 297A/G, 467C/T, 526C/G, 657C/T, 703G/A, 742C/T, 796C/A, 803G/C, 930G/A heterozygotes by direct DNA sequencing. After cloning and sequencing, it was obtained the B101 and one novel A allele. The novel allele has one nucleotide change at 742 position C to T compared with A102, which results in an amino acid Arg to Cys at 248 position and was nominated as A213. It is concluded that C742T mutation of the α1, 3 N-acetyl-D-galactosaminyl-transferase gene can lead to A2 phenotype and with anti-A1 antibody in serum.

Effects of the ABO-mismatch between donor and recipient of cryopreserved arterial homografts

AIM

Cryopreserved arterial homograft (CAH) is a well-established substitute material for in situ reconstruction of vascular infections. However, their degeneration remains serious complication. Although several studies propose ABO-mismatching between CAH-donor and -recipient as the main reason, the results are controversial. We compared the outcome between ABO-compatible and ABO-incompatible CAH recipients to evaluate the contribution of ABO-mismatching.

METHODS

Between January 2004 and December 2007, a retrospective review in 32 patients who underwent CAH-implantation was performed. The patients were divided in ABO-incompatible (group A: 17/32 patients; 53%) and ABO-compatible (group B: 15/32 patients; 47%) to CAH donor. Leucocytes, platelets and C-reactive protein (CRP) levels were recorded during the in-hospital stay. These were correlated with the surface of implanted homograft (SIH). Mid-term survival- and freedom-from-reoperation (FFR) rates were also calculated.

RESULTS

In both groups, peak of leucocytes and CRP was recorded on third postoperative day (POD3) and regarding platelets lowest values on POD1. Interestingly, a second CRP-peak was reported on POD8 in group A (A: 172±104mg/L vs. B: 75±55mg/L, P=0.01). No relationship between second CRP-peak and SIH was found. After 27 months median follow-up (range, 5-49 months), survival- (65% vs. 84%, P=0.28) and FFR-rates (94% vs. 93%, P=0.98) remained comparable.

CONCLUSION

We consider that the second CRP-peak expresses an early cytoimmunologic response of ABO-incompatible recipients against CAH. However, we did not find any relationship between ABO-incompatibility and poor mid-term outcome in terms of reoperation or mortality. Longer surveillance of our patients is mandatory.

[Effect of ABO-incompatible allogeneic stem cell transplantation on erythroid lineage hematopoiesis]

This study was purposed to investigate the effect of ABO-incompatible allogeneic hematopoietic stem cell transplantation (allo-HSCT) on erythroid lineage hematopoiesis. The changes of ABO group, IgM and IgG antibody in 16 patients received ABO-incompatible allo-HSCT were detected. The results showed that ABO-incompatible allo-HSCT were successfully engrafted in 16 patients, and there was no difference in reconstitution of platelets and neutrophils between ABO-incompatible and ABO-compatible transplantation (p > 0.05). The time of erythroid lineage reconstitution was prolonged (p < 0.05), the disappearance time of isoagglutinins against donor-type RBC in major and bidirectional ABO-incompatible recipients was correlated with the time of erythroid lineage reconstitution. It is concluded that ABO-incompatible allo-HSCT may lead to prolong recovery of erythroid lineage hematopoiesis. Before transplantation, the removal of anti-donor isoagglutinins by plasmapheresis or transfusion of donor's erythrocytes for neutralizing the isoagglutinins against donor's erythrocytes in the recipients may facilitate RBC engraftment and reduce erythrocyte transfusion.

Clearance of maternal isohemagglutinins from infant circulation (CME)

BACKGROUND

Non-group O neonates require testing for passively acquired maternal isohemagglutinins for them to receive type-specific red blood cells (RBCs), according to the latest edition of the AABB Standards. A neonate is defined as an infant up to 4 months old in the AABB Standards, and many blood banks tend to stop testing for maternal anti-A and/or anti-B after 4 months of age. In lieu of such testing, group O RBCs are usually transfused to infants up to 4 months of age. This practice can limit the overall supply of group O RBCs available to other patients.

STUDY DESIGN AND METHODS

A retrospective study of 1309 infants up to 4 months of age was performed, to assess the age by which passively acquired maternal isohemagglutinins are cleared from infant circulation. Detection of isohemagglutinins was performed by mixing sample sera and observing agglutination, followed by incubation and addition of anti-immunoglobulin anti-human globulin (antiglobulin test phase).

RESULTS

The data show that 6.4% of infants up to 1 month of age had maternal isohemagglutinins, while none of the infants ranging from 2 to 4 months of age had maternal isohemagglutinins in their sera.

CONCLUSIONS

Maternal isohemagglutinins are rare after the first month of life and patients who are at least 2 months old can safely receive ABO type-compatible RBC units without testing for passively acquired maternal anti-A and/or anti-B.