EFFECTS OF BRANCHED-CHAIN AMINO ACID-ENRICHED NUTRIENT MIXTURE ON NATURAL-KILLER-CELL ACTIVITY IN VIRAL CIRRHOSIS

A controlled study was performed in 18 viral cirrhosis patients to eva luate whether immune function, as indicated by natural killer (NK) cel l activity, was improved by a branched-chain amino acid-enriched nutri ent mixture (nutrient-mixture), Aminoleban EN. Five patients received the nutrient-mixture (100 g/day) for 2 to 6 weeks preceded by control periods. Five additional patients received the nutrient-mixture for 2 to 4 weeks, and the remaining 8 patients did not receive the nutrient- mixture. NK cell activity, CD16, CD8, CD11b, and amino acids were assa yed before and after the administration of the drug in the nutrient-mi xture-supplemented group, and two times with 1 to 6 month intervals in the control group. In the nutrient-mixture-supplemented group (n = 10 ), increasing NK cell activity, expressed as the ratio of values of po st-treatment to that of baseline (ratio > 1.25) was detected in 7 (70% ) patients, whereas in the control group (n = 13), it was detected in only 1 (7.7%) (p < 0.01). While in the affected group (NK cell activit y ratio > 1.25, n = 7), all patients had compensated liver cirrhosis, in the unaffected group (NK cell activity ratio < 1.25, n = 3), 2 of 3 patients had decompensated liver cirrhosis (p < 0.02). Laboratory dat a, indicating severity of liver cirrhosis, such as total bilirubin and albumin, showed better values (p < 0.01, p < 0.05 respectively), and baseline NK cell activity was low (8.7 +/- 7.2% vs 33.3 +/- 13.0%, p < 0.05) in the affected group than unaffected group. NK cell subpopulat ions such as CD16 (%), CD11b (%) and one of the populations of T cell such as CD8 (%) showed no significant change throughout the study. As for amino acids analysis, Fischer's ratio was increased in the nutrien t-mixture-supplemented group compared to the control group (p < 0.05), but none of the amino acids showed significant change. Thus the chang es in NK cell activity were not explained by increase in NK cell subpo pulations nor changes of amino acids. These results suggest that the b ranched-chain amino acid-enriched nutrient mixture increases NK cell a ctivity moderately in patients who have compensated liver cirrhosis an d shows lower values of baseline NK cell activity.