The effects of bleomycin on immunocompetence in man.

Bleomycin was administered to six patients with advanced cancer. Multiple parameters of both antibody- and cell-mediated immunity were followed serially to characterize the effects of bleomycin on immunocompetence in humans. Antibody-mediated immunity, including primary vaccination with keyhole limpet hemocyanin, was not depressed. While there was no significant suppression of cell-mediated immunity, phytohemagglutinin-stimulated lymphocyte blastogenesis was reduced after treatment with bleomycin. The in vitro effects of bleomycin on lymphocyte stimulation were studied, and while thymidine incorporation was significantly inhibited by bleomycin, leucine incorporation was not reduced even at high concentrations of bleomycin. We have concluded that bleomycin does not suppress immunocompetence in man.