Natural cell-mediated cytotoxicity in cutaneous T-cell lymphomas

Natural cell-mediated cytotoxicity was studied in 24 patients with cutaneous T-cell lymphomas and in 18 age- and sex-matched controls studied concomitantly. Percent cytotoxicity was determined by 4-h ⁵¹Cr release assay using K562 targets at effector to target ratios of 100:1, 50:1, and 25:1. Mean percent cytotoxicity was significantly lower in patients than in controls at an effector to target cell ratio of 100:1. Likewise, decreased cytotoxicity was found at effector to target ratios of 50:1 and 25:1, although this difference was not significant. When natural killer activity was analyzed separately for males and females, cytotoxicity was lower in both, although the decrease was significant only for male patients. Impairment of natural killer activity did not correlate with blood zinc levels, but appeared to correlate with stage of disease.