The role of immunohistochemical staining with ck7 in the differential diagnosis of autoimmune hepatitis

Abstract

INTRODUCTION: Although the immunohistochemical staining with cytokeratin 7 (CK7) is an adjuvant method for identifying various components of the intrahepatic biliary system, the expression of CK7 does not occur in hepatocytes. In the literature, some studies suggest that a group of cells having dual morphologic and immunophenotypic characteristics of bile duct epithelium and hepatocytes, referred to as progenitor stem cells, was stained positive with CK7.MATERIALS AND METHODS: In this study, we examined a total of 219 cases diagnosed with autoimmune hepatitis, chronic hepatitis B, chronic hepatitis C, and primary biliary cholangitis between 2005 and 2017 in Uludag University, Faculty of Medicine, Department of Medical Pathology.RESULTS: The comparisons of AIH cases with HepB, HepC and PBC cases demonstrated that the immunoreactivity to CK7 was significantly higher in the AIH group (p < 0.005) compared to the groups of HepB and HepC, whereas no significant differences were found between the AIH and PBC groups.CONCLUSIONS: In our study, it was concluded that the immunoreactivity to CK7 could be used as an adjuvant treatment to the clinicopathologic assessment in distinguishing between the AIH cases and chronic viral hepatitis. However, since CK7 immunoreactive hepatocytes were widely detected also in patients with chronic viral hepatitis, and there was no statistically significant difference between the PBC and AIH cases, it has been established that the inclusion of CK7 immunoreactivity into the diagnostic histopathological criteria for AIH would not be convenient (Tab. 1, Fig. 1, Ref. 22).