Expression of intercellular adhesion molecule ICAM-1 and cytokeratin as Potential markcrs of disease activity in the Egyptian pattern of chronic hepatitis C

ABSTRACT

Chronic hepatitis C [ch.HCV] and schistosomal hepatic fibrosis or both as a mixed hepatic lesion [MHL] are among the most common causes of endemic chronic hepatic disease in Egypt. Adhesion molecules especially ICAM-1 play an important role in inflammatory and immunological responses of chronic liver disease. Cytokeratin 18 [CK-18], although normally expressed in hepatic tissue, yet it is altered during chronic inflammatory hepatic lesions. This work was planned to study ICAM-1 as expressed in hepatic tissue in the different grades of the disease activity, in relation to its circulating levels in patients sera, and to evaluate the level of CK-18 expression in relation to the different grades of chronic inflammation and stages of fibrosis in the examined liver biopsies. The material for this study comprised 33 patients [17 ch.HCV and 16 MHL]. Seven cases, that proved to have nearly normal serological data and insignificant histopathological hepatic features, were considered as controls. All patients were assessed for HCV serological markers as well as serum levels of soluble ICAM-1 [sICAM-1] by the Enzyme Linked Immunosorbent. Assay [ELISA]. Liver needle biopsy specimens were processed and assessed for the histopathological grade of the disease activity and stage of fibrosis of the hepatic lesion. Tissue expression of ICAM-1 and CK-18 was detected using immunohistochemical techniques. Our results revealed significantly higher levels of serum sICAM-1 in both ch.HCV and MHL groups compared to controls [p<0.01]. Meanwhile, higher levels of sICAM-1 were recorded in the MHL cases relative to ch.HCV cases. ICAM-1 expression was not detected in any of the control cases, while it was positively expressed in all ch. HCV and MHL cases, with a higher score recorded in the later group [P>0.001 compared to the control group]. ICAM-1 expression was detected mainly within the sinusoidal cells [endothelial and Kupffer cells], hepatocytes, mononuclear inflammatory cells and vascular endothehail cells in portal areas. On classifying patients according to their grades of active inflammation and stages of fibrosis, higher scores of ICAM-1 expression within the hepatic tissue were recorded in cases with more active inflammatory grades and higher fibrotic stages. On the other hand, serum of ICAM-1 levels though were significantly elevated in patients with higher grades of inflammatory activity yet, they were decreased in patients with higher fibrotic stages. CK18 expression was mainly detected within hepatocytes of the periportal areas [in a combined membranous and intracytoplasmic pattern], as well as within the bile ducts epithelium in the portal areas. Over expression of CKI 8 was detected in both the ch.HCV and MHL groups [p<0.001 relative to controls], but the expression scores were higher in the MHL group. From these results we may conclude that MHL is a more aggressive and active chronic inflammatory hepatic disease than ch.HCV alone. Also, serum levels of sICAM-1 as well as hepatic expression of both ICAM-1 and CK-18 are related to the degree of disease activity, which may point out to the possibility of using serum sICAM-1 levels as well as the expression scores of hepalic ICAM-1 and CK-18 as efficient tools for monitoring the disease activity in ch. HCV and MHL patients. While ICAM-1 expression in tissue could be used as indicator for the stage of fibrosis in those patients also recommend that both ICAM-1 in serum andhepatic tissue could be used for monitoring the effect of therapy on the studied pattern of chronic hepatitis C