Phenotypic Analysis of Lymphocytes Involved in Major Histocompatibility Complex Unrestricted Cellular Cytotoxicity in Patients with Alcoholic Cirrhosis

Lymphocyte subpopulations known to exert major histocompatibility complex (MHC) unrestricted cytotoxicity were enumerated in 33 patients with alcoholic cirrhosis and in 10 patients with alcohol-induced fatty changes of the liver. Absolute numbers and percentages of lymphocytes bearing the CD57 (median 12 vs. 20%; p = 0.007) and CD16 (median 12 vs. 19%; p = 0.0027) antigens were significantly reduced in cirrhotic patients as compared to healthy control individuals, whereas no significant change in CD56+ cells (median 13 vs. 13%; n.s.), comprising a subpopulation with a high natural killer activity in normal individuals, was observed. A subset of these cells, cytotoxic T cells coexpressing CD56 and CD3 antigens and capable of MHC-unrestricted cellular cytotoxicity, was significantly increased in patients with alcoholic cirrhosis as compared to healthy control individuals (median 2 vs. 1 %; p = 0.024). Patients with alcohol-induced fatty changes of the liver did not show any deviation of lymphocyte subpopulation from normal. The finding that lymphocyte subsets capable to exert most of the MHC-unrestricted cytotoxic capacity in peripheral blood (CD56+ non-T-cells and CD3 + CD56+ T cells) were unchanged or even increased in number suggests that the reduced natural killer cell activity known to occur in patients with alcoholic liver cirrhosis might be due to a functional defect of these cells. Furthermore, our results indicate that changes in frequency of MHC-unrestricted cytotoxic cells are not found in a similar manner in all subsets of these cells, but are dependent on the particular cell surface marker investigated.