A single intrapleural injection of transforming growth factor-beta(2) produces an excellent pleurodesis in rabbits

The purpose of the present study was to determine whether the intrapleural injection of transforming growth factor beta(2) (TCF-beta(2)) would produce a pleurodesis in rabbits. Single intrapleural injections of TGF-beta(2) at doses of 5.00 mu g (n = 12), 1.67 mu g (n = 10), 0.50 tig (n = 10), or 0.1 67 mu g (n = 4), or of the parenteral buffer alone (n = 5) were given in a volume of 2 mi to New Zealand white rabbits. Chest tubes were left in place for at least 72 h. pleural fluid was aspirated at 24-h intervals and was m easured and subjected to chemical analysis. The animals were killed 14 d af ter the injection. The intrapleural injection of TGF-beta(2) resulted in a dose-dependent pleurodesis (on a scale of 0 to 4, where 0 = no pleurodesis and 4 = complete pleurodesis) with mean scores of 3.6, 2.6, 1.5, 0.7, and 0 .3 for the groups that received 5.0, 1.67, 0.50, and 0.167 mu g of TGF-beta 2 and buffer alone, respectively. Intrapleural injection of the larger dos es of TGF-beta(2) resulted in the formation of a large amount of pleural fl uid. The fluid had a significantly lower white blood cell (WBC) count and l actate dehydrogenase (LDH) level than did the fluid that results from the i ntrapleural injection of 10 mg/kg doxycycline or 400 mg/kg talc slurry. On the basis of this study we conclude that a single intrapleural injection of TCF-beta(2) induces pleurodesis in a dose-dependent manner. A dose of 5.0 mu g produced satisfactory pleurodesis in almost all of the rabbits so trea ted. Larger doses of TGF-beta(2) induced larger pleural effusions with rela tively low pleural fluid WBC counts and LDH levels. The ability of TGF-beta to produce a pleurodesis in patients with recurrent pleural effusions or p neumothorax should be investigated. A single intrapleural injection of TGF- beta, may produce a pleurodesis both safely and painlessly.