Bcl-2 and Fas expression in peripheral blood leukocytes of patients with alcoholic and autoimmune liver disorders

This article is devoted to the inquiry of three diseases of the liver: alcoholic liver disease (ALD), primary biliary cirrhosis (PBC), and autoimmune hepatitis (AIH). The aim of the study was to assess the changes in populations of circulating lymphocytes expressing antiapoptotic bcl-2 molecule and proapoptotic Fas (cluster of differentiation 95(CD95)) receptor in patients with ALD, AIH, and PBC.

The study population consisted of 110 patients with ALD (n = 50), PBC (n = 30), and AIH (n = 30) and age-matched healthy volunteers (n = 25). Peripheral blood lymphocytes were isolated, stained with monoclonal antibodies against CD4, CD8, and CD19 antigen; intracellular bcl-2; and surface Fas receptor (CD95) antigens, and estimated using the flow cytometric method.

Bcl-2 expression was the highest in CD4+ and CD19+ T lymphocytes in ALD; however, only the differences in median/mean fluorescence intensity values of CD4+bcl-2+ lymphocytes between ALD and PBC group and CD19+bcl-2+ between ALD and PBC groups were statistically significant, indicating the different role of B cells in pathology of ALD and PBC. In contrast to that, statistically significant higher percentage of CD4+, CD8+, and CD19+ bearing Fas receptor in all groups of patients with liver diseases in comparison with the control subjects were estimated. The highest expression of Fas in CD4+ lymphocytes in ALD and in CD8+ cells of PBC and AIH groups were detected.

Low expression of bcl-2 molecule and high expression of Fas in peripheral blood lymphocytes indicate significant dysregulation of apoptotic mechanisms not only in the liver but also in peripheral blood lymphocytes in all examined groups, especially in ALD group.