Immunologic function during adjuvant BCG immunotherapy for malignant melanoma: Induction of anergy

Abstract

Serial tests of immunological function were performed on 28 patients participating in a randomized controlled clinical trial of adjuvant Tice-stain BCG immunotherapy administered by tine technique for malignant melanoma. Cryopreserved lymphocyte samples obtained prior to study entry and at 3 and 6 months there-after were tested by mixed lymphocyte culture (MLC), cell-mediated lympholysis (CML), antibody-dependent cell-mediated cytotoxicity (K cell), and natural killing (NK cell) assays, the last two assays being performed with the Chang cell line. Delayed-type hypersensitivity (DTH) skin tests to recall antigens were performed at the same intervals. At entry to the study in vitro lymphocyte reactivity of patients was similar to that of normal controls, and most (75%) of the patients reacted to at least one recall antigen. Serial lymphocyte reactivity measured by the in vitro tests was not different in the BCG and control groups, but BCG treatment was associated with a marked, statistically significant (P<0.01) reduction in DTH skin test reactivity. BCG therapy was not shown to delay recurrence of the disease.