Sequential in vitro reactivity of lymphocytes from melanoma patients receiving immunotherapy compared with the reactivity of lymphocytes from healthy donors.

A microcytotoxicity technique was used to determine the sequential in vitro reactivity against melanoma cells of lymphocytes from melanoma patients receiving immunotherapy and from healthy donors. Lymphocytes were collected 2 weeks for 2-3 months and were stored in liquid nitrogen until use. Preliminary studies had indicated that freezing did not effect the reactivity of lymphocytes. Lymphocytes from 10 healthy donors tested against melanoma cells exhibited substantial reactivity which showed no consistent pattern over time. Lymphocytes from 9 melanoma patients exhibited increased reactivity after immunotherapy. Patterns of reactivity against melanoma cells and against bladder carcinoma cells were similar, indicating lack of specificity for melanoma antigens. Correlations with clinical course of the disease were not apparent.