title: Pleural fluid transforming growth factor-beta1 correlates with pleural fibrosis in experimental empyema.
abstract: Transforming growth factor-beta1 (TGF-beta1) is a growth factor that is implicated in fibrosis of many organs. The purpose of this study was to determine the sequential levels of TGF-beta1 in the pleural fluid of rabbits that had undergone empyema induction, as fibrosis of the pleural space develops. Thirty-seven rabbits underwent empyema induction. Rabbits were sacrificed on Days 1, 2, 3, 4, 5, 6, and 8. Pleural fluid and viscera pleura specimens were collected at autopsy. TGF-beta1 levels were measured in pleural fluid using a commercially available ELISA kit, and pathologic specimens were scored for evidence of fibrosis (pleural thickness and number of fibroblasts). The median levels of pleural fluid TGF-beta1 increased from 8,100 pg/ml (Days 1 and 2) to 39,600 pg/ml (Day 8). Pleural fluid TGF-beta1 levels closely correlated with microscopic pleural thickness (r = 0.7, p < 0.001) and number of fibroblasts present in the visceral pleura (r = 0.68, p < 0.001). The first increase in pleural fluid levels of TGF-beta1 (Day 3) occurred before the increase in pleural thickness (Day 4) and before the increase in number of fibroblasts (Day 4). In conclusion, pleural fluid levels of TGF-beta1 rise in experimental empyema as pleural fibrosis develops. The rise in empyemic pleural fluid TGF-beta1 levels correlates with markers of pleural space fibrosis.
authors.affiliation: Section of Pulmonary and Critical Care, Department of Medicine, Pathology and Laboratory Medicine Services, Long Beach Veterans Affairs Medical Center, Long Beach, California, USA. scott.sasse@med.va.gov
authors.forename: Scott A
authors.initials: SA
authors.lastname: Sasse
authors.forename: Martin R
authors.initials: MR
authors.lastname: Jadus
authors.forename: Gary D
authors.initials: GD
authors.lastname: Kukes
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004653:Empyema / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005355:Fibrosis / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D010995:Pleural Diseases / Q000378:metabolism / Q000473:pathology*; D010996:Pleural Effusion / Q000737:chemistry*; D011336:Probability; D011817:Rabbits; D012680:Sensitivity and Specificity; D016212:Transforming Growth Factor beta / Q000032:analysis*; D053773:Transforming Growth Factor beta1
chemical_list: D015415:Biomarkers; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1