RESUMO
HLA-B*15:04:04 differs from HLA-B*15:04:01 by one nucleotide at codon 238 (gat > gac).
Assuntos
Alelos , Doadores de Sangue , Éxons , Antígeno HLA-B15/genética , Ensaio de Proficiência Laboratorial/normas , Mutação Puntual , Sequência de Bases , Transfusão de Sangue , Brasil , Códon/química , Antígeno HLA-B15/imunologia , Haplótipos , Teste de Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
HLA-A*02:481 differs from HLA-A*02:01:01:01 by one nucleotide and was found in four unrelated Brazilians.
Assuntos
Alelos , Antígeno HLA-A2/genética , Sequência de Bases , Brasil , Feminino , Antígeno HLA-B15/genética , Antígenos HLA-C/genética , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Humanos , Masculino , Dados de Sequência MolecularRESUMO
The aim of this study was to investigate association of human leucocyte antigens (HLA)-DRB1 and DQB1 polymorphisms with hepatitis C virus (HCV) infection and with the occurrence of severe liver fibrosis/cirrhosis in chronically infected patients. Ninety-nine white patients, from southeast Brazil, with confirmed HCV chronic infection were included in the study. Severe fibrosis/cirrhosis (METAVIR scores F3-F4) was present in 49 patients. HLA-DRB1 specificities and DRB1*11 and DQB1* alleles were determined by PCR-SSP, and their frequencies were compared between patients and a control group of 103 healthy white Brazilian individuals. The results confirmed previous reports of the association of DRB1*11 and DQB1*03 with protection from chronic HCV infection, but did not confirm their association with protection from severe fibrosis/cirrhosis. Furthermore, the results suggested that the polymorphic sites on HLA molecules responsible for protection from chronic HCV infection are encoded not only by the DRB1*1101 and DQB1*0301, as suggested in the literature, but also by other DRB1*11 and DQB1*03 alleles. Thus, we hypothesized that the common polymorphic residues shared by different DRB1*11 and/or DQB1*03 alleles might be responsible for selection of viral epitopes for presentation to CD4(+) T cells, leading to an efficient immune response against the virus.
Assuntos
Genes MHC da Classe II , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Hepatite C Crônica/imunologia , Adolescente , Adulto , Idoso , Alelos , Brasil , Linfócitos T CD4-Positivos , Epitopos , Feminino , Cadeias beta de HLA-DQ , Cadeias HLA-DRB1 , Hepatite C Crônica/genética , Hepatite C Crônica/patologia , Humanos , Cirrose Hepática/imunologia , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo GenéticoRESUMO
HLA-B*52:21 differs from the closest, HLA-B*52:01:02, by two nucleotides (CTG â TGG), leading to an amino acid substitution from Leu to Trp at codon 156.
Assuntos
Alelos , Substituição de Aminoácidos , Códon/genética , Antígenos HLA-B/genética , Sequência de Bases , Brasil , Humanos , Dados de Sequência MolecularRESUMO
Human leucocyte antigen (HLA)-B*4509 differs from the closest HLA-B*4502 by three nucleotides that lead to changes of Tyr113His, Asn114Asp and Phe116Ser. HLA-B*5212 differs from HLA-B*520101 by a single nucleotide substitution, leading to a change of Asn114Asp.
Assuntos
Antígenos HLA-B/genética , Alelos , Substituição de Aminoácidos , Sequência de Bases , Brasil , DNA/genética , Primers do DNA/genética , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Homologia de Sequência do Ácido NucleicoRESUMO
It was recently shown that IL-2 gene single nucleotide polymorphism (SNP) at position -330 (G-->T) is related to in vitro cytokine production levels, with the T/T and T/G genotypes being associated with low production and the G/G genotype associated with high production. The objective of this study was to investigate a possible influence of this polymorphism on renal and cardiac allograft outcomes. IL-2 SNP G-T (-330) was determined by PCR-RFLP in 67 recipients of heart allografts and in 63 recipients of renal grafts from HLA-haplo-identical, related donors. A higher frequency of the T/T genotype was observed in renal transplant patients who experienced at least one acute rejection episode during the first 3 months after transplantation than in those without rejection during this period (80% vs 49%, respectively, P <.05). Accordingly, the same genotype tended to be more frequent in renal recipients with a 6-month serum creatinine level above 1.5 mg/dL (median value for the whole group of kidney recipients) than in patients with lower creatinine levels (79% vs 45%, P <.08). Regarding cardiac transplant recipients, no associations were observed concerning acute rejection or graft survival. The finding of the association of T/T but not T/G genotype with acute kidney rejection was unexpected considering that both genotypes were shown to be associated with equal (low) IL-2 in vitro production. Further studies are necessary not only to dissect the nature of IL-2 T/T genotype association with kidney rejection, but also to explain why this genotype does not apparently influence cardiac allograft outcome.
Assuntos
Transplante de Coração/imunologia , Interleucina-2/genética , Transplante de Rim/imunologia , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Doença Aguda , Creatinina/sangue , Genótipo , Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade , Humanos , Fenótipo , Polimorfismo de Fragmento de Restrição , Fatores de Tempo , Resultado do TratamentoAssuntos
Regulação da Expressão Gênica , Transplante de Coração/fisiologia , Teste de Cultura Mista de Linfócitos , Biópsia , Células Cultivadas , Sondas de DNA , Regulação da Expressão Gênica/imunologia , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Transplante de Coração/patologia , Humanos , Linfócitos/imunologia , Análise de RegressãoAssuntos
Rejeição de Enxerto/epidemiologia , Transplante de Coração/imunologia , Proteínas de Membrana/genética , Receptores de Fator de Crescimento Neural/genética , Receptores do Fator de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Adulto , Antígenos CD/genética , Ligante CD27 , Regulação da Expressão Gênica/imunologia , Rejeição de Enxerto/imunologia , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Receptores de Fator de Crescimento Neural/imunologia , Receptores do Fator de Necrose Tumoral/imunologia , Estudos Retrospectivos , Fatores de Risco , Transplante Homólogo/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose TumoralRESUMO
T-cell immune response cDNA 7 (TIRC7) is a recently described T-cell costimulatory molecule that exhibits a central role in T-cell activation in vitro and in vivo. The present study was undertaken to investigate association between intragraft and peripheral blood mononuclear cell (PBMC) TIRC7 mRNA levels and cardiac allograft rejection in humans. TIRC7 gene expression levels were determined by a quantitative-competitive reverse transcriptase-polymerase chain reaction (QC-RT-PCR) in endomyocardial biopsies and in PBMC from cardiac transplant recipients. Biopsies collected during rejection or up to 15 days before rejection showed heightened TIRC7 mRNA expression in comparison with biopsies without rejection. All prerejection and rejection biopsies showed TIRC7 mRNA upregulation, while this was present in only 30% of the biopsies without rejection. Regarding TIRC7 mRNA in PBMC, transplant recipients showed lower levels than healthy individuals and, in contrast to the results obtained in biopsies, the levels were lower during rejection than in rejection-free periods. In summary, TIRC7 mRNA expression levels increase in biopsies and decrease in peripheral blood during acute cardiac rejection. We conclude that intragraft detection of TIRC7 transcripts is a useful tool not only for the diagnosis but also for the prediction of acute heart allograft rejection episodes.