Autoimmune vitiligo: detection of antibodies to melanin-producing cells

Vitiligo, a disorder characterized by the destruction of melanocytes, is often associated with diseases in which there are increased frequencies of autoantibodies. For this reason we investigated two patients with vitiligo, alopecia universalis, mucocutaneous candidiasis, and multiple endocrine insufficiencies for antibodies to melanin-producing cells. Using direct immunofluorescence of normal and vitiliginous skin from both patients and indirect immunofluorescence with both patients' serum, we could not detect these antibodies. However, an immunofluorescent complement-fixation test demonstrated a circulating antibody that bound to melanocytes in human skin, nevus cells and melanoma cells. Specificity of cellular fluorescence for nevus and melanoma cells was shown on serial sections stained with hematoxylin and eosin and was inferred for melanocytes from their distribution in human skin and their presence when the normal but not vitiliginous skin of both patients was used as substrate. This antibody was characterized as an IgG that activated complement via the classical pathway.