Transforming growth factor beta(2) induced pleurodesis is not inhibited bycorticosteroids

Background-Talc and tetracyclines induce pleurodesis by directly injuring t he pleura. The injury results in intense inflammation which subsequently le ads to fibrosis. Corticosteroids can inhibit talc pleurodesis by reducing t he inflammatory process. We hypothesised that transforming growth factor be ta (2) (TGF beta (2)), a fibrogenic cytokine with immunomodulatory function s, could induce effective pleurodesis without generating significant pleura l inflammation and therefore remain effective despite coadministration of c orticosteroids. Methods-Thirty rabbits were divided into two groups. Rabbits in the steroid group received weekly intramuscular injections of triamcinolone diacetate (0.8 mg/kg). Ten rabbits in each group were given 5.0 mug TGF beta (2) intr apleurally via a chest tube while the remaining five received 1.7 pg TGF be ta (2). Pleurodesis was graded macroscopically after 14 days from I (none) to 8 (> 50% symphysis). Results-TGF beta (2) produced excellent pleurodesis at both 5.0 mug and 1.7 mug doses. The pleural effusions produced after the injection were low in all inflammatory markers. No significant differences were seen between the steroid group and controls in macroscopic pleurodesis scores (7.2 (1.3) v 7 .1 (1.2)), levels of inflammatory markers in the pleural fluids (leucocyte 1107 (387)/mm(3) v 1376 (581)/mm(3); protein 3.1 (0.3) mg/dl v 2.9 (0.3) mg /dl, and LDH 478 (232) IU/1 v 502 (123) IU/1), and the degree of microscopi c pleural fibrosis and pleural inflammation. Conclusions-TGF beta (2) can induce effective pleurodesis and remains effec tive in the presence of high dose parenteral corticosteroids.