[Experimental and clinical studies on intrapleural instillations of interleukin-2 (IL-2) in patients with malignant pleural effusion].

The author investigated the anti-tumor effect of lymphokine-activated killer (LAK) cell induced by culture in IL-2 and performed intrapleural instillation of IL-2 in patients with malignant pleural effusion on the original protocol. The original protocol had been designed to keep high concentration of IL-2 in the effusion. The mean LAK activity in advanced esophageal cancer patients was not depressed as compared with other disease of patients and normal individuals. LAK cells expressed the surface markers of OKIa1, Leu7, and OKT8. Clinically pleural effusions and malignant cells in the effusion disappeared in all of the 12 pleural cavities in 10 patients. Therefore the validity of this therapy was 100% (CR: 3 cases, PR: 7 cases). Mean survival time from the initial administration of IL-2 was 9.0 months. Fever and eosinophilia were the main side effects of instillation of IL-2, but the symptoms were temporary and not so serious. The results suggested that intrapleural instillations of IL-2 should be highly recommended for patients with malignant pleural effusion. It seems that cytotoxic LAK cells derived from Tumor Infiltrating Lymphocytes (TIL) in the effusion with high concentration of IL-2 might be effective to eliminated malignant cells.