Genetic variability of hepatitis B and C viruses in Brazilian patients with and without hepatocellular carcinoma.

Most cases of hepatocellular carcinoma (HCC) are due to chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection worldwide. The aim of this study was to determine the viral genotypes and frequency of 17 mutations (15 for HBV and 2 for HCV), described previously as able to influence the course of chronic liver disease, in patients with and without HCC. This transversal study included 157 Brazilian patients with chronic hepatitis B (n = 51) and C (n = 106). Of these, 12 and 40 patients had HBV- and HCV-related HCC, respectively. Nucleotide sequencing of core promoter, pre-core, and pre-S/S regions of HBV and core region of HCV strains was performed to determine their genotypes and the frequency of the respective mutations. Among the HBV isolates, subgenotype A1 was the most prevalent in both patients with (90%) and without (61%) HCC. Fourteen out of the 15 mutations under study, as well as five different pre-S deletions, were identified. Core promoter T1753V, A1762T, and G1764A mutations were more frequent in patients with HCC than in those without, although with no statistical difference. However, a significant correlation was observed between T1753V mutation and elevation of transaminases levels (P < 0.05). As for HCV, mutation at residue 70 in the core protein of genotype 1b strains was significantly more frequent in patients with cirrhosis (56.3%) than in those without (9.1%) (P = 0.018). The detection of some key mutations in the genomes of HBV and HCV might be helpful to predict the clinical outcome of patients with chronic liver disease.

Identification of novel recombinants of hepatitis B virus genotypes F and G in human immunodeficiency virus-positive patients from Argentina and Brazil.

Hepatitis B virus (HBV) genotype G (HBV/G) infection is almost always detected along with a co-infecting HBV strain that can supply HBeAg, typically HBV/A2. In this study we describe, in two human immunodeficiency virus (HIV)-positive patients from Argentina and Brazil, the first report of HBV/G infection in Argentina and co-circulation of HBV/G, HBV/F and G/F recombinants in the American continent. HBV isolates carrying the 36 bp insertion of HBV/G were the most prevalent in both patients, with >99 % of colonies hybridizing to a probe specific for this insertion. Phylogenetic analyses of full-length genomes and precore/core fragments revealed that F4 and F1b were the co-infecting subgenotypes in the Brazilian and Argentinian patients, respectively. Bootscanning analysis provided evidence of recombination in several clones from both patients, with recombination breakpoints located mainly at the precore/core region. These data should encourage further investigations on the clinical implications of HBV/G recombinants in HBV/HIV co-infected patients.

Evaluation of saliva specimens as an alternative sampling method to detect hepatitis B surface antigen.

In this study, a modified enzyme immunoassay (EIA) was evaluated for the Hepatitis B surface antigen (HBsAg) among whole saliva and oral fluid samples. Specimens were collected from 115 individuals who gave serum and oral fluid using Salivette (Sarstedt, Nümbrecht, Germany) and whole saliva. Saliva specimens were tested following a modified ELISA, and the results were compared with paired serum specimens that were tested according to the supplier's instructions. Transport buffer for the oral fluids, sample volume for assay, incubation period of sample with conjugate as well as cut-off values were evaluated to optimize the assay. The highest sensitivity and specificity were obtained by increasing the incubation of sample and conjugate to 16 hr and using the area under the receiver operating characteristic curve to calculate cut-off values. HBsAg was detected in 40 oral fluids and 44 whole saliva samples out of 47 paired positive serum specimens and not detected in 64 oral fluids and 63 whole saliva samples out of 68 matched negative sera samples by the ELISA assay. There was excellent agreement between the results for the serum and saliva specimens kappa value (κ): 0.80 for oral fluid and κ: 0.87 for whole saliva and there was excellent reproducibility. Using an optimized protocol, the sensitivities of whole saliva and oral fluid were 93.6 and 85.1%, respectively, whereas specificities of whole saliva and oral fluid were 92.6 and 94.1%, respectively. Our data showed a significant promise for the use of whole saliva and oral fluid together with the modified commercial EIA for Hepatitis B virus infection surveillance.

Is the rapid virologic response a positive predictive factor of sustained virologic response in all pretreatment status genotype 1 hepatitis c patients treated with peginterferon-alpha2b and ribavirin?

INTRODUCTION: Currently it is not yet defined if the rapid virologic response (RVR) can predict a sustained virologic response (SVR) in relapsers and nonresponders. OBJECTIVE: To evaluate treatment-RVR as a predictive factor of SVR in genotype 1 hepatitis C treatment naive, relapsers, and nonresponder patients treated with pegylated interferon-alpha (PEG-IFN-alpha2b) and ribavirin. METHODS: One hundred sixty-seven genotype 1 hepatitis C patients who were treated with PEG-IFN-alpha2b and ribavirin and had SVR assessed were included. Hepatitis C virus RNA analysis at the fourth week of treatment was performed in all patients. The exclusion criteria were hepatitis B virus and/or HIV co-infection. A comparative analysis was performed between the groups with and without RVR and a logistic regression model was applied. RESULTS: One hundred sixty-seven patients were analyzed, 103 (62%) were naives, 22 (13%) relapsers, and 42 (25%) nonresponders. The SVR rates were 44% in naives, 68% in relapsers, and 12% in nonresponders. RVR was attained in 51/167 (31%) patients and in this group the SVR was higher than in those without RVR (75% vs. 23%; P<0.001). This difference was also observed in all subgroups: naives (71% vs. 29%; P=0.001), relapsers (92% vs. 40%; P=0.02), and nonresponders (50% vs. 8%; P=0.06). A stepwise logistic regression model identified RVR and absence of cirrhosis as the factors independently associated to SVR. CONCLUSIONS: RVR and absence of cirrhosis are the strongest predictive factors of SVR in HCV genotype 1 patients. Assessment of RVR is very useful in all pretreatment status patients in predicting SVR and provides information for individualizing therapy.

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates.

BACKGROUND: Hepatitis B virus (HBV) isolates have been classified in eight genotypes, A to H, which exhibit distinct geographical distributions. Genotypes A, D and F are predominant in Brazil, a country formed by a miscegenated population, where the proportion of individuals from Caucasian, Amerindian and African origins varies by region. Genotype F, which is the most divergent, is considered indigenous to the Americas. A systematic molecular characterization of HBV isolates from different parts of the world would be invaluable in establishing HBV evolutionary origins and dispersion patterns. A large-scale study is needed to map the region-by-region distribution of the HBV genotypes in Brazil. RESULTS: Genotyping by PCR-RFLP of 303 HBV isolates from HBsAg-positive blood donors showed that at least two of the three genotypes, A, D, and F, co-circulate in each of the five geographic regions of Brazil. No other genotypes were identified. Overall, genotype A was most prevalent (48.5%), and most of these isolates were classified as subgenotype A1 (138/153; 90.2%). Genotype D was the most common genotype in the South (84.2%) and Central (47.6%) regions. The prevalence of genotype F was low (13%) countrywide. Nucleotide sequencing of the S gene and a phylogenetic analysis of 32 HBV genotype F isolates showed that a great majority (28/32; 87.5%) belonged to subgenotype F2, cluster II. The deduced serotype of 31 of 32 F isolates was adw4. The remaining isolate showed a leucine-to-isoleucine substitution at position 127. CONCLUSION: The presence of genotypes A, D and F, and the absence of other genotypes in a large cohort of HBV infected individuals may reflect the ethnic origins of the Brazilian population. The high prevalence of isolates from subgenotype A1 (of African origin) indicates that the African influx during the colonial slavery period had a major impact on the circulation of HBV genotype A currently found in Brazil. Although most genotype F isolates belonged to cluster II, the presence of some isolates belonging to clusters I (subgroup Ib) and IV suggests the existence of two or more founder viral populations of genotype F in Brazil.