Aims: Some cases of acute-onset autoimmune hepatitis (AIH) develop into severe or fulminant forms showing massive/submassive hepatic necrosis, and have a poor prognosis. The pathological features of acute-onset AIH remain uncertain. Ductular (intermediate) hepatocytes after massive/submassive necrosis may serve as hepatic progenitor cells, and could be seen as cytokeratin 7 (CK7)-positive hepatocytes in immunohistochemistry. Therefore, the aim was to examine histological features to obtain a better evaluation of acute-onset AIH.
Methods: The histological features of 27 clinically acute-onset AIH patients were examined by immunohistochemistry using CK7.
Results: On staining for CK7, intermediate hepatocytes were less commonly present (P < 0.001) and ductular reactions were more commonly present (P < 0.001) in severe/fulminant patients than in non-severe ones. In severe and fulminant patients, intermediate hepatocytes and intralobular progenitor cells were more commonly present (P < 0.005 and P < 0.05, respectively) and ductular reactions were less commonly present (P = 0.007) in recovered patients than in dead ones. Severe patients had more clinically and histologically advanced disease.
Conclusions: Immunohistochemical evaluation using CK7 might be a useful tool for evaluating liver regeneration, and intermediate hepatocytes and progenitor cells might play an important role in liver regeneration after massive and submassive necrosis in acute-onset AIH.
© 2011 Blackwell Publishing Limited.