Transforming growth factor-beta(2) induces pleurodesis significantly faster than talc

Transforming growth factor-beta (2) (TGF-beta (2)) has recently been shown to produce effective pleurodesis in rabbits. Conventional pleurodesing agen ts such as talc act by inducing pleural injury, which results in acute infl ammation and fibrosis. TGF-beta (2) is a profibrotic cytokine capable of pr oducing fibrosis without inducing significant pleural inflammation. We hypo thesize that intrapleural administration of TGF-beta (2) would (1) produce an effective pleurodesis faster; (2) stimulate more collagen deposition, an d (3) induce less inflammation when compared with intrapleural injection of talc. Thirty rabbits were divided into two groups and given either TGF-bet a (2) (7.7 mug) or talc slurry (400 mg/kg) via a chest tube. Five rabbits f rom each group were killed at Days 1, 4, and 7. Cross pleurodesis was grade d from 1 (none) to 8 (complete symphysis). The microscopic pleural inflamma tion and fibrosis were graded from 0 to 4, Pleural thickening and the total area of collagen deposition were compared. intrapleural injection of TGF-b eta (2) produced effective pleurodesis within 7 d (median pleurodesis score = 7 at Day 7). At Day 7, TGF-beta (2) induced significantly more collagen deposition (19.4 +/- 19.6% versus 4.6 +/- 2.9% of total area of pleura at D ay 7), higher pleural fibrosis score (3.0 +/- 1.0 versus 1.8 +/- 0.5), and pleural thickness (286 +/- 191 versus 85 +/- 37 mum) than did talc. There w as no difference in the degree of pleural inflammation between the two grou ps at Day 7 (2.6 +/- 0.9 for TGF-beta (2) versus 2.4 +/- 0.6 for talc) or a t any other time points. In conclusion, the intrapleural administration of TGF-beta (2) produced excellent pleurodesis in rabbits at a rate faster tha n talc slurry and all other pleurodesing agents investigated before. TGF-be ta (2) stimulated more collagen deposition without inducing excess inflamma tion when compared with talc slurry. TGF-beta (2) may have advantages over talc slurry in the management of recurrent pleural effusion and pneumothora x.