Serum‐mediated blocking of cell‐mediated anti‐tumor immunity in a melanoma patient: Association with BCG immunotherapy and clinical deterioration

Abstract

Abstract A patient with melanoma was found to have lymphocytes highly cytotoxic for autogenous tumor cells but not for fibroblasts. Autogenous serum did not block the cytotoxicity. He then received an injection of BCG into a small tumor nodule. Three weeks later, in association with accelerated clinical deterioration, his lymphocytes were still cytotoxic, but his serum could now block completely the tumor‐specific lymphocyte reactivity.