Clinical features of autoimmune hepatitis with acute presentation: a Japanese nationwide survey.

Background: Autoimmune hepatitis (AIH) is characterized by progressive inflammation and necrosis of hepatocytes and eventually leads to a variety of phenotypes, including acute liver dysfunction, chronic progressive liver disease, and fulminant hepatic failure. Although the precise mechanisms of AIH are unknown, environmental factors may trigger disease onset in genetically predisposed individuals. Patients with the recently established entity of AIH with acute presentation often display atypical clinical features that mimic those of acute hepatitis forms even though AIH is categorized as a chronic liver disease. The aim of this study was to identify the precise clinical features of AIH with acute presentation.
Methods: Eighty-six AIH patients with acute presentation were retrospectively enrolled from facilities across Japan and analyzed for clinical features, histopathological findings, and disease outcomes.
Results: Seventy-five patients were female and 11 were male. Patient age ranged from adolescent to over 80 years old, with a median age of 55 years. Median alanine transaminase (ALT) was 776 U/L and median immunoglobulin G (IgG) was 1671 mg/dL. There were no significant differences between genders in terms of ALT (P = 0.27) or IgG (P = 0.51). The number of patients without and with histopathological fibrosis was 29 and 57, respectively. The patients with fibrosis were significantly older than those without (P = 0.015), but no other differences in clinical or histopathological findings were observed. Moreover, antinuclear antibody (ANA)-positive (defined as × 40, N = 63) and -negative (N = 23) patients showed no significant differences in clinical or histopathological findings or disease outcomes. Twenty-five patients experienced disease relapse and two patients died during the study period. ALP ≥ 500 U/L [odds ratio (OR) 3.20; 95% confidence interval (CI) 1.12-9.10; P < 0.030] and GGT ≥ 200 U/L (OR 2.98; 95% CI 1.01-8.77; P = 0.047) were identified as independent risk factors of disease relapse.
Conclusions: AIH with acute presentation is a newly recognized disease entity for which diagnostic hallmarks, such as ALT, fibrosis, and ANA, are needed. Further investigation is also required on the mechanisms of this disorder. Clinicians should be mindful of disease relapse during patient care.