Risk factors for hepatocellular carcinoma in Japanese patients with autoimmune hepatitis type 1

Hepatocellular carcinoma (HCC) is occasionally seen even in patients with autoimmune hepatitis (AIH) without prior infection either with hepatitis C virus (HCV) or hepatitis B virus. The aim of this study was to identify the incidence of and risk factors for HCC with AIH in a large-scale population with a long-term follow-up in Japan.

One hundred and eighty patients diagnosed with AIH were enrolled (F/M = 159/21; mean age, 59.9 years; mean observation period, 80.2 months). Patients with positive HCV antibody/serum HCV RNA and/or positive HBs Ag were excluded. Initial treatment included immunosuppressant therapy (n = 147), other drugs (n = 28), and no drug (n = 5). Patients underwent abdominal ultrasonography at intervals of 3-6 months during observation. Patients' demographic factors, biochemical data, liver histology, medications, response to treatment, and complications were evaluated in relation to HCC.

During the observation period, six patients (3.3%) developed HCC. Univariate analysis showed that risk factors for HCC were cirrhosis at diagnosis with AIH (p = 0.0002), absence of a treatment response (p = 0.033), abnormal alanine aminotransferase (ALT) at the final observation (p = 0.0002), and diabetes (p = 0.0015). Multivariate analysis showed that risk factors for HCC were cirrhosis at diagnosis of AIH (odds ratio 4.08) and abnormal ALT at final observation (odds ratio 3.66).

This retrospective study showed that cirrhosis at diagnosis of AIH and abnormal ALT at final observation were independently associated with HCC development. It is important to pay attention to the presence of cirrhosis at diagnosis of AIH and to normalize ALT.