CD81 expression in peripheral blood lymphocytes before and after treatment with interferon and ribavirin in HIV/HCV coinfected patients

BACKGROUND: CD81 is expressed on lymphocytes and confers HCV viral infectivity support. The aim of our study was to quantify CD81 expression in peripheral blood B- and T-cells of HCV/HIV-coinfected patients and healthy subjects to examine its association with several HCV virological characteristics and the therapeutic responsiveness to HCV antiviral treatment. METHODS: We carried out a cross-sectional study on 122 naïve patients. For a duration of 48 weeks, 24 out of 122 patients underwent HCV antiviral therapy with interferon (IFN)-alpha and ribavirin. T- and B-cell subsets were analysed by flow cytometry. RESULTS: We found that HIV/HCV coinfected patients with HCV-RNA > or =850 000 IU/mL had lower values of %CD19+CD81-CD62L+ and %CD19+CD62L+; and higher values of CD19+CD81+CD62L- and CD19+CD81+ percentages and absolute counts than patients with HCV-RNA <850 000 IU/mL. Similarly, HIV/HCV coinfected patients with the genotype 1 had lower values of %CD19+CD81-CD62L+ and higher values of CD3+CD81+CD62L- and CD3+CD81+ percentages and absolute counts than patients without genotype 1. Moreover, we found that HIV/HCV coinfected patients had higher values of %CD19+HLA-DR+CD25+, %CD19+CD40+CD25+ and %CD19+CD25+ than healthy control patients. When we studied the B- and T-cell subset kinetics of 24 HIV/HCV coinfected patients on HCV antiviral therapy, we found a significant decrease in CD3+CD81+and CD3+CD81+CD62L- subsets and a significant increase in CD3+CD62L+ and CD3+CD81+CD62L+ percentages and absolute counts, but the variation in these markers disappeared several months after stopping the treatment. CONCLUSIONS: We observed a different pattern of CD81 T-cell and B-cell levels in naïve HIV/HCV coinfected patients according to HCV virological status and their subsequent variations during HCV antiviral treatment. CD81 expression might influence HCV pathogenesis and response to HCV antiviral treatment.