[Effect of immunotherapy using the non-specific immunopotentiator OK-432 in malignant ovarian tumors--selecting...

Immunotherapy for malignant ovarian tumors has been discussed in a number of recent studies. However, the effects of this therapy are produced by an indirect mechanism, and are, therefore, difficult to evaluated. In order to select appropriate cases for immunotherapy using OK-432 against malignant ovarian tumors, clinical and experimental studies were carried out. Clinically patients with ovarian cancer were divided into two groups; OK-432 treated group and no immunotherapy groups. As a parameter of immunoresponse to OK-432, PHA and Su-PS skin tests were performed periodically. Natural killer (NK) cell activity was also measured before and after administration of OK-432. Peripheral blood lymphocyte subsets were analysed by using monoclonal antibody and a laser flow cytometer. Finally tumor growth velocity was evaluated in tumor transplanted nude mice. The survival rate was used as an index for evaluation. The survival rate of the OK-432 treated groups was better than the control groups in advanced cases, but a statistically significant difference was found between the two groups. Among fundamental studies which were carried out to select appropriate cases, Su-PS skin test, the NK response of OK-432 seemed to be actually utilized.