Cell surface antigens of human malignant melanoma. II. Serological typing with immune adherence assays and definition of two new surface antigens.

Immune adherence assays revealed that 10 out of 18 melanoma patients had demonstrable antibody to surface antigens of autologous cultured melanoma cells, with serum titers ranging from 1/4 to 1/160. Autologous fibroblasts showed no reactions with these sera. Antibody from individual patients showed reproducible temperature preference for maximal reactivity. Two new melanoma antigenic systems were defined in this study. The first, BD, was restricted to autologous melanoma and could not be demonstrated in absorption tests on 12 allogeneic melanoma cell lines. The other, AH, was found on 5 of 12 melanomas and represents a class of shared melanoma surface antigens. Neither BD nor AH antigen was found on normal cells from autologous, allogeneic, or xenogeneic sources or on any nonmelanoma tumor cell line. Methods are now available to develop a comprehensive serological classification of the surface antigens of melanoma.