OK-432 Induces Production of Neutrophil Chemotactic Factors in Malignant Pleural Effusion

We investigated the changes in cellular components and neutrophil chemotactic factors in pleural fluid from 19 lung cancer patients who received intrapleural injection of OK-432 to treat malignant pleurisy. Not only neutrophil chemotactic activity (NCA) but also neutrophil count and percentage were increased significantly at 6 hours after OK-432 injection. The neutrophil count was significantly correlated with NCA level. The levels of C5a and IL-8 in pleural fluid were increased significantly after OK-432 injection. The increased IL-8 level was associated with a increase of both NCA and neutrophil count. OK-432 treatment also induced a marked increase of IL-1 beta and IL-6 in pleural fluid. Thus, intrapleural injection of OK-432 induced production of neutrophil chemotactic factors (IL-8 and C5a) and cytokines (IL-1 beta and IL-6), which eventually attracted neutrophils into the pleural space. These observations suggest that neutrophil migration mediated by these factors and cytokines may contribute to the sclerosing effects of OK-432 treatment.