RESUMO
The reduction of hepatic microsomal transfer protein (MTP) activity results in fatty liver, worsening hepatic steatosis and fibrosis in chronic hepatitis C (CHC). The G allele of the MTP gene promoter, -493G/T, has been associated with lower transcriptional activity than the T allele. We investigated this association with metabolic and histological variables in patients with CHC. A total of 174 untreated patients with CHC were genotyped for MTP -493G/T by direct sequencing using PCR. All patients were negative for markers of Wilson’s disease, hemochromatosis and autoimmune diseases and had current and past daily alcohol intake lower than 100 g/week. The sample distribution was in Hardy-Weinberg equilibrium. Among subjects with genotype 1, 56.8 percent of the patients with fibrosis grade 3+4 presented at least one G allele versus 34.3 percent of the patients with fibrosis grade 1+2 (OR = 1.8; 95 percentCI = 1.3-2.3). Logistic regression analysis with steatosis as the dependent variable identified genotypes GG+GT as independent protective factors against steatosis (OR = 0.4, 95 percentCI = 0.2-0.8; P = 0.01). The results suggest that the presence of the G allele of MTP -493G/T associated with lower hepatic MTP expression protects against steatosis in our CHC patients.
Assuntos
Adulto , Feminino , Humanos , Proteínas de Transporte/genética , Fígado Gorduroso/genética , Hepatite C Crônica/genética , Polimorfismo Genético/genética , Progressão da Doença , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Predisposição Genética para Doença , Genótipo , Hepatite C Crônica/metabolismo , Hepatite C Crônica/patologia , Reação em Cadeia da PolimeraseRESUMO
Brazil is a country of continental dimension with a population of different ethnic backgrounds. Thus, a wide variation in the frequencies of hepatitis C virus (HCV) genotypes is expected to occur. To address this point, 1,688 sequential samples from chronic HCV patients were analyzed. HCV-RNA was amplified by the RT-PCR from blood samples collected from 1995 to 2000 at different laboratories located in different cities from all Brazilian States. Samples were collected in tubes containing a gel separator, centrifuged in the site of collection and sent by express mail in a refrigerated container to Laboratório Bioquímico Jardim Paulista, São Paulo, SP, Brazil. HCV- RNA was extracted from serum and submitted to RT and nested PCR using standard procedures. Nested PCR products were submitted to cycle sequencing reactions without prior purification. Sequences were analyzed for genotype determination and the following frequencies were found: 64.9 percent (1,095) for genotype 1, 4.6 percent (78) for genotype 2, 30.2 percent (510) for genotype 3, 0.2 percent (3) for genotype 4, and 0.1 percent (2) for genotype 5. The frequencies of HCV genotypes were statistically different among Brazilian regions (P = 0.00017). In all regions, genotype 1 was the most frequent (51.7 to 74.1 percent), reaching the highest value in the North; genotype 2 was more prevalent in the Center-West region (11.4 percent), especially in Mato Grosso State (25.8 percent), while genotype 3 was more common in the South (43.2 percent). Genotypes 4 and 5 were rarely found and only in the Southeast, in São Paulo State. The present data indicate the need for careful epidemiological surveys throughout Brazil since knowing the frequency and distribution of the genotypes would provide key information for understanding the spread of HCV.
Assuntos
Humanos , Hepacivirus/genética , Hepatite C Crônica/virologia , RNA Viral/genética , /genética , Sequência de Bases , Brasil/epidemiologia , Genótipo , Hepatite C Crônica/epidemiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas do Envelope Viral/genéticaRESUMO
Patients with sickle-cell anemia submitted to frequent blood transfusions are at risk of contamination with hepatitis C virus (HCV). Determination of HCV RNA and genotype characterization are parameters that are relevant for the treatment of the viral infection. The objective of the present study was to determine the frequency of HCV infection and the positivity for HCV RNA and to identify the HCV genotype in patients with sickle-cell anemia with a history of blood transfusion who had been treated at the Hospital of the HEMOPE Foundation. Sera from 291 patients were tested for anti-HCV antibodies by ELISA 3.0 and RIBA 3.0 Chiron and for the presence of HCV RNA by RT-PCR. HCV genotyping was performed in 19 serum samples. Forty-one of 291 patients (14.1 percent) were anti-HCV positive by ELISA and RIBA. Both univariate and multivariate analysis showed a greater risk of anti-HCV positivity in those who had started a transfusion regime before 1992 and received more than 10 units of blood. Thirty-four of the anti-HCV-positive patients (34/41, 82.9 percent) were also HCV RNA positive. Univariate analysis, used to compare HCV RNA-negative and -positive patients, did not indicate a higher risk of HCV RNA positivity for any of the variables evaluated. The genotypes identified were 1b (63 percent), 1a (21 percent) and 3a (16 percent). A high prevalence of HCV infection was observed in our patients with sickle-cell anemia (14.1 percent) compared to the population in general (3 percent). In the literature, the frequency of HCV infection in sickle-cell anemia ranges from 2 to 30 percent. The serological screening for anti-HCV at blood banks after 1992 has contributed to a better control of the dissemination of HCV infection. Because of the predominance of genotype 1, these patients belong to a group requiring special treatment, with a probable indication of new therapeutic options against HCV