Effect of intrapleural and/or intraperitoneal lentinan therapy patients with malignant pleural and/or peritoneal effusion

Twenty lesions of sixteen patients with malignant pleural and/or peritoneal effusion were treated with the intrapleural and/or intraperitoneal lentinan therapy (4mg/week×4). And the following results were obtained. Malignant effusion disappeared in six lesions and diminiched in two. In thirteen lesions, the cytological grade decreased. Totally, sixteen lesions (80%) revealed clinical effect. Toxicity caused a high fever in only one case. Subpoplations (CD4^＋, CD8^＋, CD8^＋CD11^＋, CD8^＋CD11^－) of pleural or peritoneal effusion lymphocytes and peripheral blood lymphocytes showed no change during the course of lentinan therapy. NK activites of peripheral blood mononuclear cells (PBM) after this treatment were significantly lower (P＜0.05) than before treatment. However, NK and anti-Daudi activities of pleural or peritoneal effusion mononuclear cells (PEM tended to be augmented and high LAK activities of PEM were maintained by lentinan therapy. Augmentation of cytotoxicity in PEM induced by lentinan may lead to clinical effect. Patients with high NK activitied of PBM before treatment showed clinical effect. Thus, this therapy may be useful even for patients with malignant pleural or peritoneal effusion.