Melanoma and Vitiligo Are Associated With Antibody Responses to Similar Antigens on Pigment Cells

BACKGROUND AND DESIGN: Several clinical observations suggest that there is a link between vitiligo and melanoma. We examined whether an immune response to similar antigens on pigment cells could account for this association. We tested 30 patients with melanoma, 29 patients with vitiligo, and 28 patients with unrelated conditions for antibodies to human melanocyte antigens using an immunoprecipitation sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis assay. RESULTS: Antibodies to melanocytes were present in 24 (80%) patients from the melanoma group, 24 (83%) patients from the vitiligo group, and in two (7%) patients from the control group. The antibodies in patients with melanoma or vitiligo were directed to similar antigens with molecular weights of approximately 40 to 45, 75, and 90 kd. The frequency of antibody responses to each of these antigens was similar in both diseases. By sequential immunodepletion, the antigens defined by antibodies in both diseases were similar. These antigens were also expressed on melanoma cells. CONCLUSIONS: Most patients with melanoma or with vitiligo develop antibodies to similar antigens that are present both on melanocytes and on melanoma cells. These findings support the hypothesis that the clinical link between the two diseases results from immune responses to antigens shared by normal and malignant pigment cells.