Detection of Antibodies to Human Melanoma Cells in Vitiligo and Alopecia Areata by Western Blot Analysis

Antibody reactivity to human melanoma cells (SK-Mel-23) was investigated in 48 patients with vitiligo, 14 with alopecia areata (AA), and 35 normal control individuals by Western blot analysis. Antibodies to SK-Mel-23 were found in 44 (92%) of the patients with vitiligo, in 7 (50%) of the patients with AA, and in 14 (40%) of the normal control individuals. Significant differences between patients with vitiligo and normal controls were found in the incidence and distribution of antibodies, but no significant differences were found between patients with AA and normal controls. The antibodies were predominantly directed to one or more antigens of approximately 110 KD, 103 KD, 88 KD, 70 KD, 56 KD, 46 DK, or 41 KD. The most common responses were to 110 KD, 88KD, and 70 KD antigens. These antibodies were present in 60%, 60%, and 73% of the patients with vitiligo; 7%, 14% and 35% of the patients with AA; and 11%, 11% and 40% of normal control individuals, respectively. There were no statistical differences in the incidence of antibodies to pigment cells between segmental and non-segmental vitiligo. These findings suggest that autoreactivity to pigment cells occurs mostly in patients with vitiligo and might be a secondary immune reaction to destroyed pigment cells.