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.