Enhanced Apoptosis of Peripheral CD5-Negative B Lymphocytes from Chronically Hepatitis C Virus-Infected Patients: Reversal after Antiviral Treatment

Abstract

ABSTRACT Whereas enhanced peripheral T-cell apoptosis and its association with autoimmunity have recently been reported, the apoptotic status of peripheral B cells in chronic hepatitis C virus (HCV) infection remains ambiguous. We therefore sought to investigate the sensitivity of peripheral B cells to apoptosis and to assess the possible benefits of antiviral treatment in mitigating these effects. Spontaneous apoptosis, the extent of apoptosis rescue, and NF-κB expression in peripheral B cells were studied in patients with chronic HCV infections (group 1), in sustained responders after antiviral treatment (group 2), and in healthy controls (group 3). For group 1, spontaneous B-cell apoptosis was increased (26% ± 4.6%) and apoptosis rescue was altered (39%) compared to group 3 (18% ± 5% and 50%, respectively; P = 0.001). In contrast, apoptosis and apoptosis rescue were similar for groups 2 and 3. Enhanced B-cell apoptosis was associated with decreased NF-κB expression and was found only in CD5-negative (CD5 neg ) B cells, whereas CD5 pos cells were apoptosis resistant. Chronic HCV infection is associated with enhanced peripheral B-cell apoptosis and decreased apoptosis rescue. Successful antiviral treatment reverses these abnormalities to the levels seen in healthy individuals. The relative resistance of the CD5 pos B-cell subpopulation to apoptosis may play a role in HCV-related autoimmunity and lymphoproliferation.