Transforming growth factor β2 induced pleurodesis is not inhibited by corticosteroids
- aDepartments of Pulmonary Medicine, St Thomas Hospital and Vanderbilt University, Nashville, Tennessee, USA, bDepartment of Medicine, University of Western Australia, Perth, Australia, cDivision of Respiratory Diseases, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
- Dr Y C G Lee , Department of Pulmonary Medicine, St Thomas Hospital, 4220 Harding Road, Nashville, TN 37202, USAycgarylee{at}hotmail.com
- Received 6 September 2000
- Revision requested 18 December 2000
- Revised 24 January 2001
- Accepted 9 May 2001
Abstract
BACKGROUND Talc and tetracyclines induce pleurodesis by directly injuring the pleura. The injury results in intense inflammation which subsequently leads to fibrosis. Corticosteroids can inhibit talc pleurodesis by reducing the inflammatory process. We hypothesised that transforming growth factor β2 (TGFβ2), a fibrogenic cytokine with immunomodulatory functions, could induce effective pleurodesis without generating significant pleural inflammation and therefore remain effective despite co-administration of corticosteroids.
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 μg TGFβ2 intrapleurally via a chest tube while the remaining five received 1.7 μg TGFβ2. Pleurodesis was graded macroscopically after 14 days from 1 (none) to 8 (>50% symphysis).
RESULTS TGFβ2produced excellent pleurodesis at both 5.0 μg and 1.7 μg 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)/mm3 v 1376 (581)/mm3; protein 3.1 (0.3) mg/dl v 2.9 (0.3) mg/dl, and LDH 478 (232) IU/l v 502 (123) IU/l), and the degree of microscopic pleural fibrosis and pleural inflammation.
CONCLUSIONS TGFβ2can induce effective pleurodesis and remains effective in the presence of high dose parenteral corticosteroids.
