Antimitochondrial antibodies (AMAs) are the serological hallmark for primary biliary cirrhosis (PBC). When AMAs are detected in patients with chronic hepatitis, they negatively impact on the autoimmune hepatitis (AIH) scoring system. The purpose of this study was to determine if AMAs detected in the sera of patients with overt AIH have clinical or pathological significance. All patients with a clinicopathologic diagnosis of AIH from one center were reviewed. Only those meeting the criteria for probable or definite AIH according to the International Autoimmune Hepatitis Group were included. Patients found to be consistently AMA-positive via enzyme-linked immunosorbent assay (ELISA) for pyruvate dehydrogenase complex E2 subunit were reviewed in detail. Fifteen of 126 patients with typical features of AIH (pretreatment AIH score >10) had detectable AMAs in serum. None had any histologic features suggestive of PBC. None had detectable anti-liver-kidney-microsomal antibodies. Of these 15 patients, all have remained persistently AMA-positive via ELISA. All 15 patients have been followed long-term, and their clinical course remained typical for AIH. No bile duct damage typical of PBC was seen on initial or follow-up liver biopsies.
Conclusion: Patients with overt AIH who test positive for AMAs at initial presentation and are treated with corticosteroid therapy have shown no clinical or histologic evidence of PBC despite the continued detection of AMAs over a follow-up of up to 27 years.