ABEL DA COSTA NETO
Índice h a partir de 2011
3
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- Prevalence and laboratorial determinants of the clinical relevance of antibodies of undetermined specificity(2019) CONRADO, Marina Cavalcanti de Albuquerque da Veiga; CARDOSO, Regina A.; DEZAN, Marcia Regina; OLIVEIRA, Valeria Brito; NETO, Abel da Costa; ZIZA, Karen Chinoca; KRIEGER, Jose Eduardo; PEREIRA, Alexandre Costa; SABINO, Ester Cerdeira; ROCHA, Vanderson; MENDRONE-JUNIOR, Alfredo; DINARDO, Carla LuanaBackground and Objectives Antibodies of unknown specificity (AUS) are frequently identified in the pre-transfusion testing. These antibodies can be insignificant or potentially cause post-transfusion haemolysis. Information about the prevalence of clinically relevant AUS is still lacking. Our aim was to predict the potential clinical relevance of AUS using the monocyte monolayer assay (MMA) and to identify the clinical and laboratorial determinants of AUS' significance. Materials and Methods Antibodies of unknown specificity identified at a single institution from 2015-2017 were evaluated through MMA. A monocyte index (MI) of more than 5% was predictive of potential post-transfusion haemolysis. Results Thirty-two patients with AUS were included in the study. Of the studied AUS, 37 center dot 5% (12/32) presented with a monocyte index (MI) more than 5%. In the group of significant AUS, 41 center dot 7% of the patients presented with sickle cell disease (SCD) and the AUS were associated with Rh antibodies in 75% of the cases. In the group of insignificant AUS, only 10% of the patients had SCD and the association with Rh antibodies was detected in 20% of the cases. The presence of Rh antibodies was independently associated with the AUS clinical relevance (P = 0 center dot 012). Conclusion More than one-third of the AUS are potentially clinically relevant, and the association with Rh antibodies is predictive of AUS relevance. Services must honour AUS in the pre-transfusion process in order to ensure transfusion safety.
- Fc gamma R2B B2.4 haplotype predicts increased risk of red blood cell alloimmunization in sickle cell disease patients(2020) COSTA NETO, Abel; SANTOS, Flavia; RIBEIRO, Ingrid; OLIVEIRA, Valeria; DEZAN, Marcia; KASHIMA, Simone; COVAS, Dimas; PEREIRA, Alexandre; FONSECA, Guilherme; MOREIRA, Frederico; KRIEGER, Jose; GUALANDRO, Sandra; ROCHA, Vanderson; MENDRONE JR., Alfredo; DINARDO, Carla L.BACKGROUND Red blood cell (RBC) alloimmunization is an important transfusion complication which is prevalent among sickle cell disease (SCD) patients. Autoimmune diseases are a known risk factor for RBC alloimmunization, suggesting that autoimmunity and post-transfusion alloantibody development occur through similar physiopathological pathways. Polymorphisms in the Fc gamma R2B gene have already been associated with several autoimmune disorders and hypothetically could be associated with RBC alloimmunization. Our goal was to evaluate if important polymorphisms of Fc gamma R2B have an impact on the risk of RBC alloimmunization among SCD patients. STUDY DESIGN AND METHODS This was a case-control study in which alloimmunized and non-alloimmunized SCD patients were compared in terms of the genotype frequency of the Fc gamma R2B polymorphisms -386G/C, -120 T/A, and 695C/T, genotyped through direct Sanger sequencing. RESULTS A total of 237 patients met the eligibility criteria, 120 cases (alloimmunized) and 117 controls (non-alloimmunized). RBC alloimmunization was associated with female sex (p < 0.001), lifetime number of RBC units transfused (p = 0.002) and 120 T/A Fc gamma R2B genotype (p = 0.031). The Fc gamma R2B promoter region haplotype 2B.4 (386C120A) was positively associated with RBC alloimunization (p = 0.045). The logistic regression (LR) model identified female sex (OR 10.03, CI 95% 5.16-19.49; p < 0.001) and Fc gamma R2B 2B.4 haplotype (OR 4.55, CI95% 1.1118.65; p = 0.035) as independent predictors of RBC alloimmunization in SCD patients. CONCLUSION SCD patients with the Fc gamma R2B 2B.4 haplotype had over a fourfold higher risk for RBC alloimmunization. This highlights the role played by Fc gamma R2B on RBC alloimmunization and may be helpful in identifying the immune responders.
- SMIM1 intron 2 gene variations leading to variability in Vel antigen expression among Brazilian blood donors(2019) DEZAN, Marcia Regina; COSTA-NETO, Abel; GOMES, Carolina Nunes; RIBEIRO, Ingrid Helena; OLIVEIRA, Valeria Brito; V, Marina C. A. Conrado; OLIVEIRA, Theo Gremen M.; CARVALHO, Mariana L. P.; ARANHA, Aline Fernanda; BOSI, Silvia R. A.; SALLES, Nanci A.; KRIEGER, Jose Eduardo; PEREIRA, Alexandre Costa; SABINO, Ester Cerdeira; ROCHA, Vanderson; MENDRONE-JUNIOR, Alfredo; DINARDO, Carla Luana; LEVI, Jose EduardoBackground: There is a significant inter-individual heterogeneity of Vel antigen expression which can lead to inaccuracies on Vel phenotyping of blood donors and, potentially, to hemolytic post-transfusion reactions. Our aim was to evaluate the impact of genetic variants in the SMIM1 intron 2 on the expression of Vel antigen among Brazilian blood donors harboring the c.64_80del17 deletion in heterozygosity. Methods: Donors presenting the SMIM1 c.64_80del17 in heterozygosity were included in the study and subjected to SMIM1 intron 2 direct sequencing aiming to genotype the following polymorphisms: rs143702418, rs1181893, rs191041962, rs6673829, rs1175550 and rs9424296. Results: SMIM1 intron 2 sequencing was performed on two hundred donors presenting one c.64_80del17 allele. The rs1175550 polymorphism significantly impacted on Vel antigen expression. Variations in the strength of agglutination on Vel phenotyping were also observed according to the rs6673829 genotype, but this difference did not persist with statistical relevance after multivariate analysis. Conclusion: The presence of the rs1175550A allele of SMIM1 is significantly and independently associated with a decrease in Vel antigen expression. Even though the population in Brazil is intensely mixed, the allele frequencies obtained in the current study were very similar to that reported for Europeans.
- FCGR2B B2.4 Haplotype Predicts Increased Risk of Red Blood Cell Alloimmunization in Sickle Cell Disease Patients(2018) NETO, Abel Costa; SANTOS, Flavia Leite; RIBEIRO, Ingrid Helena; OLIVEIRA, Valeria Brito; DEZAN, Marcia Regina; KASHIMA, Simone; COVAS, Dimas Tadeu; PEREIRA, Alexandre Costa; FONSECA, Guilherme Henrique Hencklain; MOREIRA, Frederico; KRIEGER, Jose Eduardo; GUALANDRO, Sandra Fatima Menosi; ROCHA, Vanderson; MENDRONE JR., Alfredo; DINARDO, Carla Luana