The antibody response against MART-1 differs in patients with melanoma-associated leucoderma and vitiligo

Patients with melanoma may develop skin depigmentation spontaneously or following therapy, referred to as melanoma-associated leucoderma (MAL). As clinical presentation of MAL may precede primary/metastatic melanoma detection, recognition of MAL is important to prevent its misdiagnosis as vitiligo and the subsequent application of immunosuppressive treatment. To reveal the immunity involved in MAL development, we investigated the presence of antibody and T-cell immune responses directed against the melanocyte-differentiation-antigens MART-1 (Melan-A), tyrosinase and gp100 in patients with MAL, as compared to patients with vitiligo. Autoantibodies to gp100 and tyrosinase were commonly found in both diseases. Interestingly, MART-1 antibodies were only present in patients with MAL. Melanocyte antigen-specific T cells were found in all patients, with relatively more specific T cells in patients with active vitiligo. Although MAL and vitiligo may appear clinically similar, our results indicate that the humoral immune responses against MART-1 differ between these diseases, which can help to differentiate MAL from vitiligo.