Clinical studies on cell-mediated immunity in patients with malignant disease. I. Effect of immunotherapy with OK-432 on lymphocyte subpopulation and phytomitogen responsiveness in vitro.

Immunotherapy with daily intradermal injections of OK-432, penicillin- and heat-treated lyophilized powder of Su-strain of streptococcus pyogens A3, for over a period of four weeks resulted in quantitative and qualitative effectiveness on impaired cell-mediated immunity even in many patients with far advanced cancer of the stomach or lung. In vitro lymphocyte studies following immunotherapy with OK-432 demonstrated restoration of circulating lymphocyte counts to more than 1,500/microliters, a level associated with normalized subpopulation constitution and increases of phytomitogen blastogenesis. Furthermore, a delayed hypersensitivity skin reaction to PPD was boosted or converted into a positive reaction in some cases. There was, however, no detectable, definite effect on humoral immunity after the therapy. Survival rates at three and six months after the initiation of immunochemotherapy using OK-432 and another chemotherapeutic agent, 5-fluorouracil, in 40 patients with cancer were significantly longer than those of matched control patients given chemotherapy alone.