Anti cyclic citrullinated peptide antibodies (anti-CCP) in type 1 autoimmune hepatitis (AIH-1)

Objectives. Besides the autoantibodies included in the diagnostic criteria of type 1 autoimmune hepatitis (AIH-1), many other autoantibodies have been described in this condition. Recently, antibodies against cyclic citrullinated peptide (anti-CCP) have been validated as specific diagnostic and prognostic markers of rheumatoid arthritis (RA). We aimed to assess whether these antibodies are part of the autoantibody repertoire of AIH-1 and correlate with rheumatologic manifestations. Methods. Anti-CCP were tested by a commercially available ELISA. Results. The antibodies were found in 12 out of 133 (9%) AIH-1, 2 of 49 (4%) primary biliary cirrhosis, 1 of 80 (1%) hepatitis C virus-related chronic liver disease, 53 of 89 (60%) RA sera. High titres were found only in RA and AIH-1. No clinical (in particular rheumatologic manifestations), biochemical or immunoserological differences were detectable between anti-CCP positive and negative AIH-1 sera, with the exception of rheumatoid factor, always negative in the positive ones. Conclusions. Anti-CCP can be detected in a subgroup of patients with AIH-1. They might be part of the wide range autoantibody production characteristic of this condition and/or, less probably, be predictive of future RA development. It is conceivable that the characterization of the target antigen will allow to clarify their significance.