title: Association between inflammatory mediators and the fibrinolysis system in infectious pleural effusions.
abstract: The response of the fibrinolytic system to inflammatory mediators in empyema and complicated parapneumonic pleural effusions is still uncertain. We prospectively analysed 100 patients with pleural effusion: 25 with empyema or complicated parapneumonic effusion, 22 with tuberculous effusion, 28 with malignant effusion and 25 with transudate effusion. Inflammatory mediators, tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and polymorphonuclear elastase, were measured in serum and pleural fluid. Fibrinolytic system parameters, plasminogen, tissue-type plasminogen activator (t-PA) and urokinase PA, PA inhibitor type 1 (PAI 1) and PAI type 2 concentrations and PAI 1 activity, were quantified in plasma and pleural fluid. The Wilcoxon signed-rank test was used to compare plasma and pleural values and to compare pleural values according to the aetiology of the effusion. The Pearson correlation coefficient was used to assess the relationship between fibrinolytic and inflammatory markers in pleural fluid. Significant differences were found between pleural and plasma fibrinolytic system levels. Pleural fluid exudates had higher fibrinolytic levels than transudates. Among exudates, tuberculous, empyema and complicated parapneumonic effusions demonstrated higher pleural PAI levels than malignant effusions, whereas t-PA was lowest in empyema and complicated parapneumonic pleural effusions. PAI concentrations correlated with TNF-alpha, IL-8 and polymorphonuclear elastase when all exudative effusions were analysed, but the association was not maintained in empyema and complicated parapneumonic effusions. A negative association found between t-PA and both IL-8 and polymorphonuclear elastase in exudative effusions was strongest in empyema and complicated parapneumonic effusions. Blockage of fibrin clearance in empyema and complicated parapneumonic effusions was associated with both enhanced levels of PAIs and decreased levels of t-PA.
authors.affiliation: Department of Internal Medicine, Vall d'Hebron University Hospital, Barcelona, Spain. 29261cal@comb.es
authors.forename: Carmen
authors.initials: C
authors.lastname: Alemán
authors.forename: José
authors.initials: J
authors.lastname: Alegre
authors.forename: Jasone
authors.initials: J
authors.lastname: Monasterio
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Segura
authors.forename: Lluís
authors.initials: L
authors.lastname: Armadans
authors.forename: Ana
authors.initials: A
authors.lastname: Anglés
authors.forename: Encarna
authors.initials: E
authors.lastname: Varela
authors.forename: Eva
authors.initials: E
authors.lastname: Ruiz
authors.forename: Tomás
authors.initials: T
authors.lastname: Fernández de Sevilla
mesh_terms: D016724:Empyema, Pleural / Q000276:immunology / Q000378:metabolism*; D005122:Exudates and Transudates / Q000737:chemistry; D005342:Fibrinolysis; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood / Q000378:metabolism*; D016209:Interleukin-8 / Q000032:analysis / Q000097:blood; D019272:Leukocyte Elastase / Q000032:analysis / Q000097:blood; D010958:Plasminogen / Q000032:analysis; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis; D017396:Plasminogen Activator Inhibitor 2 / Q000032:analysis; D010996:Pleural Effusion / Q000097:blood / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000097:blood / Q000378:metabolism; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D010959:Tissue Plasminogen Activator / Q000032:analysis; D014396:Tuberculosis, Pleural / Q000097:blood / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D014568:Urokinase-Type Plasminogen Activator / Q000032:analysis
chemical_list: D018836:Inflammation Mediators; D016209:Interleukin-8; D017395:Plasminogen Activator Inhibitor 1; D017396:Plasminogen Activator Inhibitor 2; D014409:Tumor Necrosis Factor-alpha; D010958:Plasminogen; D019272:Leukocyte Elastase; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator