ABO-incompatible living-donor pediatric kidney transplantation in Japan.

The Japanese ABO-Incompatible Transplantation Committee officially collected and analyzed data on pediatric ABO-incompatible living-donor kidney transplantation in July 2012. The age of a child was defined as <16 years, and 89 children who had undergone ABO-incompatible living-donor kidney transplantation from 1989 to 2011 were entered in a registry. These data were presented as the Japanese registry of pediatric ABO-incompatible living-donor kidney transplantation at the regional meetings of the International Pediatric Transplantation Association (IPTA) in Nagoya in September 2012 and in Sao Paulo in November 2012.

ABO-incompatible living-donor pediatric kidney transplantation in Japan

The Japanese ABO-Incompatible Transplantation Committee officially collected and analyzed data on pediatric ABO-incompatible living-donor kidney transplantation in July 2012. The age of a child was defined as <16 years, and 89 children who had undergone ABO-incompatible living-donor kidney transplantation from 1989 to 2011 were entered in a registry. These data were presented as the Japanese registry of pediatric ABO-incompatible living-donor kidney transplantation at the regional meetings of the International Pediatric Transplantation Association (IPTA) in Nagoya in September 2012 and in Sao Paulo in November 2012.

Autoantibody formation after alloimmunization inducing bystander immune hemolysis.

The development of RBC autoantibodies resulting from or associated with allogeneic blood transfusions is not an easily determined complication of RBC transfusions. This report discusses one patient who developed RBC autoantibodies in association with an allogeneic blood transfusion and alloimmunization leading to a temporary bystander immune hemolysis. A 72-year-old woman was hospitalized as a result of severe anemia and received two units of ABO- and D-compatible RBCs. She had a history of two pregnancies 40 years before, but no history of RBC transfusion, and her antibody screen was negative. On the tenth day after transfusion her hemoglobin dropped, and alloanti-c was identified in her serum and eluate. At this time she received another two units of compatible blood according to her phenotype (group O, R1R1, K:-1). After 48 hours, she developed joint pain, pyrexia, and hemoglobinuria, and her Hb dropped from 9.2 g/dL to 5.3 g/ dL. The direct antiglobulin test was positive, an IgG autoantibody was present in the eluate, and the antibody investigation revealed the presence of anti-Jk(b) in addition to the previously identified alloanti-c. Her genotype was determined, and, based on the findings, two additional units were selected, found to be compatible, and transfused without incident. Transfusions were discontinued, and she was treated with IVIG and corticosteroids. Her Hb increased to 9.7 g/dL, and the patient made an uneventful recovery. It was concluded that transfusion of incompatible RBCs induced the formation of an autoantibody in this patient, resulting in lysis of bystander RBCs. The need for additional blood transfusion was successfully avoided by treatment with IVIG, steroid therapy, and rituximab.

Sistema ABO e infertilidade / Infertility and blood group ABO system

OBJETIVOS: A incompatibilidade ABO está associada com algumas patologia e estudos sugerem também uma possível associação com a infertilidade. O objetivo deste estudo foi verificar se a incompatibilidade ABO entre os casais pode ser um fator contribuinte para o quadro de infertilidade. MATERIAL E MÉTODOS: Foram analisados 161 casais quanto ao grupo sangüíneo ABO e divididos em dois grupos: Grupo 1 - constituído por 72 casais férteis e grupo 2 - constituído por 89 casais inférteis. Análise estatística foi realizada pelos testes Fischers exact test e chi-square test p menor que 0,05. RESULTADOS: Os resultados mostraram um aumento significativo na incompatibilidade ABO nos casais inférteis 38(42,7%) quando comparado com a dos casais férteis 15(25%). Observamos também uma maior freqüência do grupo sangüíneo O nos homens férteis e do grupo B nos homens inférteis. CONCLUSÕES: Os resultados sugerem que a incompatibilidade ABO pode ser um fator contribuinte para a infertilidade, evidenciado pelo aumento significativo da incidência de casais ABO incompatíveis no grupo de casais inférteis

[Pure red cell aplasia after allogeneic transplantation of ABO incompatible hematopoietic stem cells]. / Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible.

ABO incompatibility in allogeneic bone marrow transplantation may be associated with incomplete or delayed erythroid engraftment, being pure red cell aplasia (PRCA) the most severe complication in this setting. Attempts for the treatment of PRCA have been made with erythropoietin or with plasmapheresis with relative success, and some authors have reported the reversibility of PRCA with antilymphocyte globulin (ALG or ATG), based on the assumption that PRCA might be immunologically mediated. We report herewith a patient with acute leukemia who developed post--BMT pure red cell aplasia. His sibling donor (sister) was HLA identical and ABO incompatible, having low agglutinin titers against donor's blood group. PRCA did not improve after treatment with erythropoietin or a boost of hematopoietic progenitor cells obtained from donor's peripheral blood but the problem was resolved completely after treatment with ALG.

Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible / Pure red cell aplasia after allogeneic transplantation of ABO incompatible hematopoietic stem cells

El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH) con incompatibilidad ABOentre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide de-sarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e in-completo de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han inten-tado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoyetina o plasmaféresis, con relativo éxito. Algunos autores han informado también la utilización de globulina antilinfocitaria, asumiendo que dicha aplasia se-lectiva de la serie roja en la médula ósea trasplantada es mediada por un mecanismo inmune. En este trabajo se describe un paciente portador de una leucemia aguda en quien se realizó un TCPH alogeneico (ABO incompatible con su donante). Teniendo niveles bajos de aglutininas contra el grupo sanguíneo de la donante, desarrolló una aplasia pura de serie roja post - TCPH. La misma no mejoró con tratamiento con eritropoyetina o con un refuerzo de progenitores hematopoyéticos de sangre periférica de la misma donante ( boost), resolviéndose totalmente lue-go de un tratamiento exitoso con globulina antilinfocitaria de origen equino (AU)

[Transplacental alloimmunization against specific platelet antigens: prevalence and features in a Chilean population]. / Aloinmunización transplacentaria por antígenos plaquetarios específicos: prevalencia y características en una población chilena.

BACKGROUND: Neonatal alloimmune thrombocytopenia (NAIT) is a result of fetomaternal incompatibility. Platelet destruction is caused by a maternal antibody directed against a fetal platelet antigen inherited from the father and lacking on the mother's platelets. The incidence and features of transplacental alloimmunization depend on the frequency of expression of platelet specific antigens; which are highly variable among different populations. AIM: To determine the prevalence and characteristics of transplacental alloimmunization in a large group of pregnant women in Chile. MATERIAL AND METHODS: We studied 3,041 samples obtained during the third trimester of gestation. In all samples, anti platelet antibodies were screened by ELISA with platelet membranes fixed to a microtiter plate. Positive samples were further studied for antigenic specificity with the monoclonal antibody specific immobilization of platelet antigens (MAIPA) test. RESULTS: Anti platelet antibodies were found in 261 samples (8.5%). The MAIPA test identified 6 samples with antibodies directed against major platelet membrane glycoproteins, 2 anti GPIb, 2 anti GPIIb/IIIa and 2 anti GPIa/IIa. In four cases, anti HLA antibodies coexisted. Two cases corresponded to well defined platelet antigen systems: one anti HPA-1a and one anti HPA-5b. No clinical evidence of thrombocytopenia of the newborn was detected in all these cases with anti GP antibodies. CONCLUSIONS: A prevalence of platelet specific antibodies of 0.2% with only one anti HPA-1a was detected. These findings are in contrast with those of other populations but in accordance with the low frequency of the HPA-1 b/b phenotype in the Chilean population. The very low incidence of platelet specific antibodies and the lack of association with clinical thrombocytopenia in the newborn, do not support the recommendation of routine antenatal screening to all women in Chile.

Prevalence and lack of clinical significance of blood group incompatibility in mothers with blood type A or B.

PURPOSE: To examine the prevalence and clinical significance of blood group incompatibility in infants whose mothers have blood type A or B. METHODS: We prospectively analyzed cord blood samples from 4996 consecutive love-born infants for blood type, hematocrit, and results of direct antiglobulin (Coombs) test (DAT) and indirect Coombs test (ICT). OUTCOME MEASURES: Erythrocyte sensitization was determined by positive DAT or ICT results. Significant hyperbilirubinemia (> or = 224 mumol/L (12.8 mg/dl) and mean cord hematocrits were compared between mother-infant pairs with ABO incompatibility and positive DAT or ICT results and those with negative Coombs test results. RESULTS: Of all births, 6.9% (343/4996) were of infants who had ABO incompatibility and had been born to mothers with blood type B or A; 44 (13%) of 343 infants had a positive antiglobulin test result, of whom 43 had a positive ICT result only. Type A or B mothers were 5.5 times less likely to have sensitization than type O mothers; A-B, B-A, A-AB, and B-AB mother-infant pairs with a positive antiglobulin test result had mean cord hematocrits and rates of significant hyperbilirubinemia similar to those of corresponding pairs whose antiglobulin tests both showed negative results. Infants with a positive DAT result had lower mean cord hematocrits than infants with negative results on both antiglobulin tests or on a positive ICT result only. Significant hyperbilirubinemia was more frequent in infants with a positive DAT result than in infants with negative results on both antiglobulin tests or a positive ICT result only. CONCLUSION: Sensitization is much rare when the mother has blood type A or B than when she has blood type O, as demonstrated by the antiglobulin test. The incidence of significant hyperbilirubinemia and lower cord hematocrit is not increased by sensitization when the mother has type A or B.

Effects of exchange transfusion on platelet counts.

With the purpose of knowing to what extent thrombocytopenia that occurs in exchange transfusion (ET) can be secondary to the procedure itself or to a generalized infection, blood counts were made in 42 neonates with hyperbilirubinemia due to maternal fetal isoimmunization of the ABO system. Platelets were quantified halfway and immediately after the exchange transfusion procedure as well as 8, 16, 24, 48 and 72 hours after. It was found that prior to ET platelet levels in donor and patient blood was similar and platelet counts were never under 100,000 mm3 (thrombocytopenia). Halfway and at the conclusion of ET, as well as 8 and 16 hours after, a decrease in platelet levels was observed. After 24 hours an increase was observed that reached basal levels prior to ET after 72 hours. In five children thrombocytopenia was observed; in two, halfway of the ET procedure, in one at the end and two more at 8 and 16 hours after ET. From results obtained we can conclude that thrombocytopenia occurring 24 hours after ET can be due to septicemia.

A guide to the use of phototherapy in the management of neonatal hyperbilirubinemia.

Nomograms have been designed to provide rational and consistent guidelines for the use of phototherapy in the management of neonatal hyperbilirubinemia. In the management of 195 neonates in the first week of life, phototherapy, given according to these nomograms, was successful, except in some severe cases of Rhesus incompatability, in controlling hyperbilirubinemia in both premature and term neonates. When compared to the more random use before the introduction of the nomograms, phototherapy was reduced significantly without an increase in the requirement for exchange transfusions.