P77 An anti-viral role for CD4+ T cells is observed in only a minority of patients successfully treated for hepatitis C virus

Introduction CD4+ T cells are thought to play an important role in the control and elimination of non-cytopathic viral infections such as HCV. However their role in patients being treated with type I IFNs is not clear. Aim To assess the role of HCV-specific CD4+ T cells in patients being treated for HCV infection. Method 33 consecutive viraemic patients undergoing treatment had ex vivo (IFNg-producing) and cultured anti-viral CD4+ T cells intensively measured at multiple time points along with viral loads, alanine transaminase and serum cytokines (IL-2, -4, -5, -6, IL-10, TNFa and IFNg). Results The patients could be divided almost equally into four groups depending on long term virus eradication or treatment failure and the magnitude of CD4+ cell responses: group 1: treatment failure, group 2–4 treatment success with group 2: no T cell responses, group 3: extremely weak transient T cell responses and group 4: strong robust responses. Early proliferation but not an ex vivo response was associated with rapid (k1 > 2 day-1) initial viral clearance and patients with robust early proliferation demonstrated reduced serum IL-10 compared to group 1 (p Conclusion Anti-viral CD4+ T cells may only have a role in a selected small group of patients in controlling viraemia, and in most patients the mechanisms of viral elimination awaits further studies.