Serological and clinical markers of autoimmune disease in HCV-infected subjects with different disease conditions.

Objective To investigate whether the serological markers of autoimmunity and the clinical features of autoimmune disease which occur in hepatitis C virus (HCV)-infected subjects are correlated to each other and/or to the clinical pattern of the disease. Methods Seventeen symptom-free, anti-HCV antibody positive subjects, 17 patients with chronic hepatitis C, 21 patients with mixed cryoglobulinemia (MC), and as controls 17 anti-HCV negative patients with dyspepsia were enrolled in a prospective study. A patient history, clinical examination, self-administered questionnaire and laboratory investigations (hepatic enzyme levels, serum HCV-RNA and anti-HCV antibody testing, and serum autoantibody profile) were performed to detect liver and/or autoimmune disease. Results Serological markers of autoimmunity and clinical findings of autoimmune disease were found to be more frequent in the HCV-infected patients considered as a whole than in controls. However, rheumatoid factor and clinical findings of autoimmune disease were more frequent in MC patients, while anti-smooth muscle antibodies not linked to symptoms or signs of autoimmune disease were detected in all groups of HCV-infected individuals, including healthy carriers and subjects who had recovered from a previous HCV infection. Conclusion Anti-smooth muscle antibodies, a serological marker of autoimmunity, are detectable in HCV-infected subjects whatever their clinical status. Clinical findings of autoimmune disease prevalently occur in patients with mixed cryoglobulinemia.