RESUMO
Hepatocellular carcinoma [BCC] represents a major health problem in many developing countries in Asia and africa including Egypt. The role of the immune system especially natural killer [NK] cells had been poorly investigated in this disease. Our study included 67 patients [thirty seven patients with HCC, 25 with liver cirrhosis [LC] both secondary to alcoholic liver disease [ALD] and chronic viral hepatitis [CVH], and 15 patients with intestinal schistosomiasis]. The results were compared with age-and sex-matched healthy controls. Peripheral blood lymphocytes [PBL] were isolated from heparinized blood and NK cell activity was studied by the standard 4-hr Cr51 release assay using erythroleukemia cell line [K562] Results of this study revealed marked suppression of NK cell activity in HCC patients compared to that of the controls. The percent NK cytotoxicity at E: T ratio 100: 1 was 41.4 +/- 21.9 in patients and 67.9 +/- 7.7 in controls. The suppression of NK activity was stage-dependent, being more evident in advanced than earlier stages of the disease. LC patients showed lower NK activity than controls. However, there was no suppression in schistosomiasis patients. We conclude that suppression of NK cyotoxicity in LC might predispose to the development of HCC in these patients, however, with progression of cancer, the degree of suppression increases markedly leading to immune system breakdown