Navegando por Palavras-chave "alloimmunization"
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- ItemSomente MetadadadosApplication of noninvasive phagocytic cellular assays using autologous monocytes to assess red cell alloantibodies in sickle cell patients(Elsevier B.V., 2004-08-01) Fabron, A.; Baleotti, W.; Mello, A. B. de; Chiba, A. K.; Kuwano, S.; Figueiredo, M. S.; Bordin, J. O.; Universidade Federal de São Paulo (UNIFESP); Fac Med MariliaWe investigated red cell (RBC) alloantibodies in 125 sickle cell anemia (SCA) patients using tube indirect antiglobulin test (PEG, LISS or enzyme) and gel centrifugation test (LISS or enzyme). Prediction of clinical significance of alloantibodies was evaluated by the monocyte monolayer assay (MMA) and the chemiluminescence test (CLT) using autologous monocytes. the alloimmunization rate was 20.8% and the gel test detected a higher number of alloantibodies than the tube test (26 v 21, p = 0.02). We observed 58.3% and 69.2% positive MMA and CLT results, respectively. Eighteen (69.2%) antibodies exhibited clinical relevance, 14 (58.3%) antibodies reacted by both MMA and CLT, while 4 (15.4%) antibodies reacted only by CLT. in conclusion, the application of phagocytic cellular assays using autologous monocytes defined clinical significance of about 70% of RBC alloantibodies detected in SCA patients. the data also suggest that the CLT may be more valuable than the MMA as a noninvasive test for predicting hemolysis after transfusion of incompatible blood in SCA patients. (C) 2004 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosGene frequencies of the HPA-15 (Gov) platelet alloantigen system in Brazilians(Blackwell Publishing Ltd, 2004-12-01) Cardone, JDB; Chiba, A. K.; Boturao-Neto, E.; Vieira, JPB; Bordin, J. O.; Universidade Federal de São Paulo (UNIFESP)The HPA-15 (Gov) alloantigen is a biallelic co-dominant system on human platelets, and its allele HPA-15a and HPA-15b differ by an A-->C single nucleotide polymorphism at nucleotide 2108 of the coding sequence resulting in a Tyr682Ser substitution in the mature CD109 glycoprotein.Employing the polymerase chain reaction-restriction fragment length polymorphism technique, we determined the HPA-15 gene frequencies among 276 subjects of distinct Brazilian ethnic groups including, 15 Caucasians, 15 African Brazilians, 15 Orientals, 106 Amazon Xikrin Indians, 31 Amazon Gavioes Indians and 94 blood donors.The calculated HPA-15a and HPA-15b allele frequencies found in Caucasians (0.53/0.47), African Brazilians (0.57/0.43), Orientals (0.57/0.43) and Brazilian blood donors (0.52/0.48) did not differ significantly. However, the HPA-15a and HPA-15b gene frequencies of Xikrin Indians (0.78/0.22) were significantly different from that of all other groups (P < 0.01). the HPA-15a/a, HPA-15a/b and HPA-15b/b genotype frequencies observed in Gavioes Indians were significantly different from those seen in African Brazilians (P = 0.04) and blood donors (P = 0.017).The present data showed that the distribution of the HPA-15 (Gov) system alleles observed among the Brazilian population is quite similar to the distributions already reported among Asian, Canadian and European populations. Moreover, the data indicated differences in the frequency of the HPA-15 system between Amazon Indians and other distinct Brazilian ethnic groups suggesting that Amerindians would be at higher risk of HPA-15 alloimmunization in the need of receiving blood components collected from blood donors of other ethnic groups.
- ItemAcesso aberto (Open Access)Human neutrophil alloantigens systems(Academia Brasileira de Ciências, 2009-09-01) Moritz, Elyse [UNIFESP]; Norcia, Ângela M. M. I. [UNIFESP]; Cardone, José D. B. [UNIFESP]; Kuwano, Sachie T. [UNIFESP]; Chiba, Akemi Kuroda [UNIFESP]; Yamamoto, Mihoko [UNIFESP]; Bordin, Jose Orlando [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Neutrophil alloantigens are involved in a variety of clinical conditions including immune neutropenias, transfusion-related acute lung injury (TRALI), refractoriness to granulocyte transfusions and febrile transfusion reactions. In the last decade, considerable progress has been made in the characterization of the implicated antigens. Currently, seven antigens are assigned to five human neutrophil antigen (HNA) systems. The HNA-1a, HNA-1b and HNA-1c antigens have been identified as polymorphic forms of the neutrophil Fcγ receptor IIIb (CD16b), encoded by three alleles. Recently, the primary structure of the HNA-2a antigen was elucidated and the HNA-2a-bearing glycoprotein was identified as a member of the Ly-6/uPAR superfamily, which has been clustered as CD177. The HNA-3a antigen is located on a 70-95 kDa glycoprotein; however, its molecular basis is still unknown. Finally, the HNA-4a and HNA-5a antigens were found to be caused by single nucleotide mutations in the αM (CD11b) and αL (CD11a) subunits of the leucocyte adhesion molecules (β2 integrins). Molecular and biochemical characterization of neutrophil antigenshave expanded our diagnostic tools by the introduction of genotyping techniques and immunoassays for antibody identification. Further studies in the field of neutrophil immunology will facilitate the prevention and management of transfusion reactions and immune diseases caused by neutrophil antibodies.
- ItemSomente MetadadadosRed blood cell alloimmunization in sickle cell disease: the influence of racial and antigenic pattern differences between donors and recipients in Brazil(Wiley-Blackwell, 1996-07-01) Moreira Junior, Gilberto [UNIFESP]; Bordin, Jose Orlando [UNIFESP]; Kuroda, Akemi [UNIFESP]; Kerbauy, José [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Red blood cell (RBC) transfusions are widely used in the management of patients with sickle cell disease (SCD). However, repeated RBC transfusions are often complicated by RBC alloimmunization. To investigate whether the frequency of RBC alloimmunization could be accounted for by racial and RBC phenotype differences between donors and recipients in Brazil, in this study we compared the RBC phenotype of 100 SCD patients with that observed in 120 randomly selected blood donors. A comparison of the RBC phenotype between the two groups revealed a statistically significant increase in the frequency of the C antigen in the donor population (P < 0.01), but no significant difference was observed for the A, B, D, c, E, e, K, k, Fy(a), M, N, S, s, and Jk(a) antigens. Using standard techniques (indirect antiglobulin test, enzyme treatment, and low-ionic-strength solution) we observed an RBC alloimmunization rate of 12.9% (11/85) in the SCD patients. Fifteen alloantibodies were detected in 11 patients, and most (80%) involved antigens in the Rhesus and Kelt systems. This observed RBC alloimmunization rate in SCD patients in Brazil is lower than that reported by studies from North America, suggesting that the requirement for extended antigen-matched RBC transfusion for SCD patients in the setting of a RBC phenotype concordant donor-recipient population may not be cost-effective in some countries. (C) 1996 Wiley-Liss, Inc.