Loss of hepatitis B surface antigen in a real-life clinical cohort of patients with chronic hepatitis B virus infection.

BACKGROUND & AIMS: Hepatitis B surface antigen (HBsAg) clearance is the main indicator of viral cure in patients infected with the hepatitis B virus (HBV). We sought to identify the parameters associated with HBsAg loss in a well-characterized real-life clinical cohort of chronically HBV-infected patients. METHODS: Patients with chronic HBV infection were prospectively included, classified according to the disease stage, and followed up to determine parameters associated with HBsAg clearance. RESULTS: In total, 315 patients were followed up for a mean of almost 6 years. At study entry, 109 (34.6%) were inactive HBsAg carriers, 204 (64.8%) had chronic active hepatitis (CAH), and two (0.6%) were immune-tolerant carriers. During follow-up, 128 (62.7%) of the 204 patients with CAH received antiviral therapy. Sixty-nine had HBeAg-positive CAH: 55 (79.7%) were treated and 14 (20.3%) untreated. One hundred thirty-five had HBeAg-negative CAH: 73 (54.1%) were treated and 62 (45.9%) untreated. Inactive carriers showed an annual HBsAg clearance incidence rate of 23.4 cases per 1000 persons-years, which was higher than that of CAH groups. The clearance incidence rates (in cases per 1000 persons-years) of CAH groups were: treated HBeAg-positive (20.7), untreated HBeAg-positive (19.1), treated HBeAg-negative (10.1), and untreated HBeAg-negative (8.1). Older age (P = 0.001) and inactive carrier status (P = 0.019) were independent predictors of HBsAg clearance. CONCLUSION: In a well-characterized real-life clinical cohort of chronically HBV-infected patients in various disease phases, older age, and inactive HBsAg carrier status were the only predictors of HBsAg clearance, whereas anti-HBV therapy only marginally increased annual incidence of HBsAg loss.

Hepatitis C virus envelope glycoprotein signatures are associated with treatment failure and modulation of viral entry and neutralization.

BACKGROUND: A major challenge for antiviral treatment of hepatitis C virus (HCV) infection is viral resistance, potentially resulting from the high variability of HCV envelope glycoproteins and subsequent selection of strains with enhanced infectivity and/or immune escape. METHODS: We used a bioinformatics and functional approach to investigate whether E1/E2 envelope glycoprotein structure and function were associated with treatment failure in 92 patients infected with HCV genotype 1. RESULTS: Bioinformatics analysis identified 1 sustain virological response (R)-related residue in E1 (219T) and 2 non-SVR (NR)-related molecular signatures in E2 (431A and 642V) in HCV genotype 1a. Two of these positions also appeared in minimal networks separating NR patients from R patients. HCV pseudoparticles (HCVpp) expressing 431A and 642V resulted in a decrease in antibody-mediated neutralization by pretreatment sera. 431A/HCVpp entry into Huh7.5 cells increased with overexpression of CD81 and SR-BI. Moreover, an association of envelope glycoprotein signatures with treatment failure was confirmed in an independent cohort (Virahep-C). CONCLUSIONS: Combined in silico and functional analyses demonstrate that envelope glycoprotein signatures associated with treatment failure result in an alteration of host cell entry factor use and escape from neutralizing antibodies, suggesting that virus-host interactions during viral entry contribute to treatment failure.

Genotype 1 hepatitis C virus envelope features that determine antiviral response assessed through optimal covariance networks.

The poor response to the combined antiviral therapy of pegylated alfa-interferon and ribavarin for hepatitis C virus (HCV) infection may be linked to mutations in the viral envelope gene E1E2 (env), which can result in escape from the immune response and higher efficacy of viral entry. Mutations that result in failure of therapy most likely require compensatory mutations to achieve sufficient change in envelope structure and function. Compensatory mutations were investigated by determining positions in the E1E2 gene where amino acids (aa) covaried across groups of individuals. We assessed networks of covarying positions in E1E2 sequences that differentiated sustained virological response (SVR) from non-response (NR) in 43 genotype 1a (17 SVR), and 49 genotype 1b (25 SVR) chronically HCV-infected individuals. Binary integer programming over covariance networks was used to extract aa combinations that differed between response groups. Genotype 1a E1E2 sequences exhibited higher degrees of covariance and clustered into 3 main groups while 1b sequences exhibited no clustering. Between 5 and 9 aa pairs were required to separate SVR from NR in each genotype. aa in hypervariable region 1 were 6 times more likely than chance to occur in the optimal networks. The pair 531-626 (EI) appeared frequently in the optimal networks and was present in 6 of 9 NR in one of the 1a clusters. The most frequent pairs representing SVR were 431-481 (EE), 500-522 (QA) in 1a, and 407-434 (AQ) in 1b. Optimal networks based on covarying aa pairs in HCV envelope can indicate features that are associated with failure or success to antiviral therapy.