Clinicopathological features of acute-onset autoimmune hepatitis.

The clinicopathological features of nine acute-onset autoimmune hepatitis (AIH) patients were compared with those of 29 classical AIH patients. The clinical features of acute-onset AIH showed significantly higher serum ALT levels, lower serum IgG levels and AIH score than those of classical AIH, although the type of auto-antibodies, age and gender were not different between the two groups. Pathological features showed that the stages of acute-onset AIH varied from stage 1 to stage 4 and were less advanced compared with those of classical AIH. One patient showed submassive hepatic necrosis. Both centrilobular necrosis and interface hepatitis were observed in 7 and 8 of 9, respectively. Three stage 1 patients with centrilobular necrosis and one patient with submassive hepatic necrosis were suggestive of acute presentation, while patients with stages 2 and 4 fibrosis were suggestive of acute exacerbation of chronic disease. An immunohistochemical study demonstrated that CD8 T cells were predominant at both interface hepatitis and centrilobular necrosis, while CD79alpha-positive B lineage cells were predominant at interface hepatitis. These results suggest that acute-onset AIH includes both acute presentation and acute exacerbation of chronic disease and that centrilobular necrosis might be a prevailing pathological feature.