Characterization of proliferative cells in malignant melanomas and their inflammatory infiltrates

Distinct changes in the antigenic phenotypes of mononuclear cells infiltrating primary and metastatic malignant melanomas (MM) have been shown to characterize distinct steps of melanoma progression. The purpose of our study is to establish whether the growth fraction of malignant melanoma cells is related to the mononuclear cell subtypes. Using monoclonal antibody Ki67, the presence of a nuclear antigen in proliferating cells of both tumor and inflammatory infiltrate cells was established in 20 primary recurrent and metastatic cutaneous melanomas. Monoclonal antibodies against lymphocyte and macrophage subsets were also applied in situ. Numerous CD8 and CD4 positive cells and natural killer (NK) cells were detected in all the infiltrates. A low CD4+/CD8+ ratio was observed in most tumors with a high proliferative activity. The presence of positive CD1+ cells seemed also to be correlated with a high activity. Our data suggest a correlation between inflammatory cell subsets and proliferative activity of MM.