[Expression of HLA-class II antigens in malignant melanoma]

Sixteen primary and ten metastatic melanoma lesions were stained in indirect immunoperoxidase with HLA-DR, DP and DQ monoclonal antibodies. In primary lesions, HLA-DR, DQ and DP antigens were much more expressed in nodular melanoma lesions than in acral lentiginous melanoma lesions. In metastatic lesions HLA-DR, DQ and DP antigens were expressed more than in primary lesions, but there were no significant differences between ALM and NM. In primary melanoma, 82%, 75%, and 75% of lesions tested were stained by anti HLA-DR, DP and DQ monoclonal antibodies, respectively. In metastatic melanoma, 90% of the lesions tested were stained by anti HLA-DR, DP and DQ monoclonal antibodies. HLA-class II antigens on melanoma cells were much more expressed in cases of high levels of invasion, high degrees of lymphocyte infiltration, and lower melanin content.