Augmentation of the generation of lymphokine-activated killer cells after a single dose of mitomycin C in cancer patients.

The effect of mitomycin C administration on the generation of cytotoxic cells, induced by in vitro activation of peripheral blood mononuclear cells (PBM) with interleukin-2, was studied in patients with various carcinomas. The ability of PBM to generate lymphokine-activated killer (LAK) cell activity against Raji cell targets was significantly augmented 5 and 7 days after a single intravenous dose of 12 mg/m2 mitomycin C, when compared to that of PBM obtained before mitomycin C injection. Further, LAK cell activity against autologous tumor cells was also significantly increased after the drug administration. The distribution of lymphocyte subsets exhibited a significant increase in the percentage of CD3+ cells after injection, with the elevation of the CD4/CD8 ratio. Furthermore, the proportion of the CD4+ Leu8+ subpopulation, which identifies inducers of suppression, was significantly reduced. Thus, the decrease in the proportion of suppressor-inducer subsets of PBM might be at least partially, responsible for the augmented generation of LAK cells after mitomycin C administration.