Relationship between natural killer activity and development of hepatocellular carcinoma in patients with cirrhosis of the liver.

Natural killer (NK) activities of peripheral blood lymphocytes (PBL) in 50 patients with non-alcoholic liver cirrhosis (LC) were prospectively studied in order to clarify the relation between the development of hepatocellular carcinoma (HCC) and impaired NK activities. Patients were divided into two groups according to their NK activities at the beginning of the study, namely, Group A with normal NK activity (n = 21) and Group B with decreased NK activity (n = 29). NK activities were serially determined in each patient for up to 40 months. During the observation period, the occurrence of HCC was identified in 12 patients (four to 36 months). Of the patients who developed HCCs, two belonged to Group A (9.5%) and 10 belonged to Group B (34.5%). These results suggest decreased NK activity in LC patients to be one of the critical factors increasing their risk of developing HCC, and serial determinations of NK activities to be important in predicting the occurrence of HCCs in following the clinical course of LC patients.