Abstract
Objective: To understand the autoimmunity associated with chronic hepatitis C (CHC), we investigated autoantibodies (autoAbs) to CD69. Methods: With this aim, we tested the reactivity of serum samples from patients with CHC and asymptomatic carriers of hepatitis C virus (HCV), as well as from patients with chronic hepatitis B (CHB) and autoimmune hepatitis (AIH), to recombinant CD69 molecules. Results: Frequencies of anti-CD69 autoAbs were 38.7% in CHC, 15.8% in AIH and 12.3% in CHB. None of the tested asymptomatic HCV carriers had autoAbs to CD69. It is important clinically that the presence of anti-CD69 autoAbs was found to be associated with a poor response to interferon-α (IFN-α) therapy. In the epitope analysis, multiple epitopes were mapped on CD69, indicating antigen-driven production of the autoAbs. Conclusion: We evidenced existence of anti-CD69 autoAbs in patients with CHC, and found that the anti-CD69 autoAb may have potential for predicting responses to IFN-α therapy.