VITILIGO AUTOANTIBODIES ARE EFFECTIVE AGAINST MELANOMA

Background. Vitiligo is a dermatologic disease characterized by local, dispersed, or diffuse white patches on the skin. The disease is defin ed as an autoimmune disorder because autoantibodies against membranal components of melanocytes are found in the patients' sera. The current study examined whether the autoantibodies reacting with the normal me lanocytes could be a potent therapy against melanoma cells. Methods. T he three in vitro assays used to determine the antibody reactivities u sing a mouse melanoma cell line B-16-F10 and M-14 human melanoma cells as targets are as follows: enzyme-linked immunosorbent assay (ELISA), proliferation assay, and morphologic examination in the presence of a ntibodies purified from sera of patients with vitiligo. In the in vivo studies, experimental melanoma was intravenously induced in C57BL/6J mice, and the mice were treated by daily intraperitoneal injections wi th purified immunoglobulin G (IgG) fraction derived either from patien ts with vitiligo or from healthy subjects. Results. The binding of IgG derived from patients with vitiligo was demonstrated by ELISA. Exposu re of melanoma cells to the vitiligo autoantibodies was followed by in hibition of their proliferation capacity. In addition, morphologic alt erations exemplified by detachment of the cells from their solid suppo rt associated with melanin release were observed in the B-16-F10 cells . Less metastatic foci developed in the lungs of the mice treated with the purified IgG fraction from the sera of patients with vitiligo com pared with those treated with purified IgG fraction from healthy subje cts. Conclusions. The results of this study point to the presence of a nti-melanoma autoantibodies in the sera of patients with localized and diffuse vitiligo. These antibodies have a destructive effect on melan oma cells in vitro and in vivo.