NATURAL-KILLER-CELL AND LYMPHOKINE-ACTIVATED KILLER-CELL ACTIVITY AGAINST MELANOCYTES IN VITILIGO

Background: Vitiligo is a common disease of unknown cause. Previous st udies have shown abnormalities in natural killer (NK) cell cytotoxicit y in patients when NK-sensitive erythroleukemic cell lines were used a s target cells. Objective: The purpose of this study was to use melano cytes directly as target cells to determine NK and lymphokine-activate d killer (LAK) cell cytotoxicity in patients with vitiligo and to dete rmine whether NK or LAK cells can be implicated in any destructive mec hanism for melanocyte cytotoxicity in vitro in this disease. Methods: Twenty-one patients with vitiligo were compared with a control group b y studying NK cell activity (NKCA) and LAK cell activity (LAKCA) on se veral target cells. These included K562 cells, neonatal melanocytes, a nd malignant melanoma cells for NKCA and neonatal melanocytes and mali gnant melanoma cells for LAKCA. Cytotoxicity was measured with the sta ndard chromium 51-release assay. Results: No significant differences w ere found between vitiligo patients and control subjects in NKCA again st K562 cells or in NKCA and LAKCA against melanocytes. Conclusion: NK cells and LAK cells are probably not responsible for melanocyte destr uction in vitiligo.