The evolving phenotype of autoimmune hepatitis across the millennium: The 40-year experience of a referral centre in Italy.

Abstract

During recent years, there have been major insight into the pathogenesis, diagnosis and treatment of autoimmune hepatitis (AIH). We aim to evaluate modifications of the clinical-epidemiological phenotype of AIH patients from 1980 to our days. Single-centre, tertiary care retrospective study on 507 consecutive Italian patients with AIH. Patients were divided into four subgroups according to the decade of diagnosis: 1981-1990, 1991-2000, 2001-2010 and 2011-2020. We assessed clinical, laboratory and histological features at diagnosis, response to treatment and clinical outcomes. Acute presentation is defined as transaminase levels >10-fold the upper limit and/or bilirubin >5 mg/dL. Complete response is defined as the normalization of transaminases and IgG after 12 months. Clinical progression is defined as the development of cirrhosis in non-cirrhotic patients and hepatic decompensation/hepatocellular carcinoma development in compensated cirrhosis. Median age at diagnosis increased across decades (24, 31, 39, 52 years, p < .001). Acute onset became more common (39.6%, 44.4%, 47.7%, 59.5%, p = .019), while cirrhosis at diagnosis became less frequent (36.5%, 16.3%, 10.8%, 8.7%, p < .001). Complete response rates rose (11.1%, 49.4%, 72.7% 76.2%, p < .001) and clinical progression during follow-up decreased (54.3%, 29.9%, 16.9%, 11.2%, p < .001). Anti-nuclear antibodies positivity increased (40.7%, 52.0%, 73.7%, 79.3%, p < .001), while IgG levels/upper limit progressively decreased (1.546, 1.515, 1.252, 1.120, p < .001). Liver-related death and liver transplantation reduced from 17.1% to 2.1% (p < .001). In the new millennium, the typical AIH patient in Italy is older at diagnosis, more often presents with acute hepatitis, cirrhosis is less frequent and response to treatment is more favourable.