Characterization of linear epitope specificity of antibodies potentially contributing to spontaneous clearance of hepatitis C virus.

BACKGROUND: Around 30% of the HCV infected patients can spontaneously clear the virus. Cumulative evidence suggests the role of neutralizing antibodies in such spontaneous resolution. Understanding the epitope specificity of such antibodies will inform the rational vaccine design as such information is limited to date. In addition to conformational epitope targeted antibodies, linear epitope specific antibodies have been identified that are broadly cross reactive against diverse HCV strains. In this study, we have characterized the potential role of three conserved linear epitopes in the spontaneous clearance of HCV. METHODS: We tested the reactivity of sera from chronic patients (CP) and spontaneous resolvers (SR) with linear peptides corresponding to three conserved regions of HCV envelope protein E2 spanning amino acids 412-423, 523-532 and 432-443 using ELISA. Subsequently, we characterized the dependency of HCV neutralization by the reactive serum samples on the antibodies specific for these epitopes using pseudoparticle-based neutralization assay. In ELISA most of the CP sera showed reactivity to multiple peptides while most of the SR samples were reactive to a single peptide suggesting presence of more specific antibodies in the SR sera. In most of the HCVpp neutralizing sera of particular peptide reactivity the neutralization was significantly affected by the presence of respective peptide. HCV neutralization by CP sera was affected by multiple peptides while 75% of the HCVpp neutralizing SR sera were competed by the 432 epitope. CONCLUSIONS: These findings suggest that individuals who spontaneously resolve HCV infection at the acute phase, can produce antibodies specific for conserved linear epitopes, and those antibodies can potentially play a role in the spontaneous viral clearance. The epitope present in the 432-443 region of E2 was identified as the primary neutralizing epitope with potential role in spontaneous viral clearance and this epitope potentiates for the design of immunogen for prophylactic vaccine.

Sofosbuvir Adverse Events Profile in a Subset of Pakistani Population.

OBJECTIVE: To determine frequency and pattern of adverse events reporting in a subset of Pakistani population being treated for chronic hepatitis C with sofosbuvir combination therapy. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Department of Medicine, Gastroenterology Division, Shalamar Hospital, Lahore, from September 2015 to May 2016. METHODOLOGY: Patients who were offered sofosbuvir therapy for treatment of chronic hepatitis C were randomly enrolled. The study subset included both treatment nave as well as retreatment groups. Patients were screened for subjective as well as objective evidence of adverse events at regular intervals. Frequency was determined. RESULTS: Among 196 patients with chronic hepatitis C, 192 patients received dual therapy consisting of ribavirin and sofosbuvir. The most frequent complaints in these subjects were fatigue, fever, myalgias and nausea accounting for 55%, 42%, 44.2% and 50%, respectively. Twenty-seven percent of patients reported with drop in hemoglobin of >2g/dl, while absolute neutropenia and moderate to severe thrombocytopenia was observed in 3% and 5% of patients, respectively. One patient died as a result of severe pancytopenia. Later derangements were all observed in patients with decompensated disease. CONCLUSION: Sofosbuvir showed less severe adverse effects in terms of symptomatology and less frequent neutropenia and thrombocytopenia as compared to previous regimens. Careful monitoring is required, especially in those with decompensated liver disease.

Dramatic response of hepatitis C patients chronically infected with hepatitis C virus genotype 3 to sofosbuvir-based therapies in Punjab, Pakistan: A prospective study.

AIM: To prospectively evaluate the efficacy of sofobuvir (SOF) in hepatitis C patients infected with hepatitis C virus (HCV) genotype 3 in Pakistan. METHODS: The present study was performed with the coordination of gastroenterology and pathology departments of Shalamar Hospital Lahore from August 2014 to May 2016. The total number of patients included in this study was 1375 and all of them were infected with HCV genotype 3. On the basis of drug combinations, all the patients were separated into two groups. The first group of patients was treated for 24 wk with SOF (Sovaldi® by Gilead Sciences) plus ribavirin (RBV) [Ribazol® by Getz Pharma Pakistan (PVT) Ltd], while the patients of the second group were treated with SOF + RBV + pegylated-interferon (pegIFN) alfa-2a (Ropegra by Roach) for 12 wk. HCV genotyping and viral load measurement were performed on fully automated Abbott Real-Time PCR system (Abbott m24sp automated nucleic acid extraction system and Abbott m2000rt amplification system; abbott Molecular, Des Plaines, IL, United States). For the assessment of sustained virological response (SVR), all HCV RNA negative patients were followed for 12 weeks after the treatment completion. Any patient with less than 12 IU/mL viral load after 12 wk of treatment completion was considered as a sustained virological responder (SVR-12). RESULTS: A total of 1375 patients chronically infected with HCV genotype 3 were treated with two drug combinations SOF + RBV and SOF + RBV + pegIFN alfa-2a. On the basis of these drug combinations, patients were divided into two groups (first and second). Overall SVR-12 was excellent in both groups (99.17% and 97.91%). Older patients (> 40 years) of second group showed lower SVR-12 (93.46%) compared to first group older patients (98.79%), while in the younger patients of both groups, the SVR-12 rate was almost the same (99.54% in first group and 99.05% in second group). No such difference regarding SVR-12 rate was seen in males and females of first group patients (99.68% and 98.88%, respectively), while in second group the males were found to be better responders compared to females (98.96% and 95%). The SVR-12 rate in previously treated patients of first group was better (99.34%) than second group (93.70%), while naïve patients of second group were marginally better responders (99.25%) than first group (97.80%). Rapid viral response at week-4 was found to be a very effective predictor for assessing the SVR rate at this stage of therapy in both groups. Headache, anemia and fatigue were common side effects in both groups either treated with SOF + RBV or SOF + RBV + pegIFN alfa-2a, while the overall percentage of the side effects was higher in second group. CONCLUSION: The remarkable SVR response rate of HCV genotype 3 infected patients to SOF provided a new way to look forward to eliminate hepatitis C from our region.