title: The contribution of factor V to the coagulant property of pleural fluid.
abstract: Intrapleural fibrin deposition commonly accompanies pleural injury and may contribute to the organization of exudative pleural effusions, which leads to lung entrapment. Previous investigators have observed an increase in procoagulant proteins in pleural effusions but very little thrombin formation. FVa is the protein cofactor in the prothrombinase complex that dramatically enhances the generation of thrombin from prothrombin by the serine protease fXa. The presence of fVa within the pleural space could influence fibrin formation and pleural scarification. We examined pleural fluids obtained from patients who had lung cancer, CHF, and empyema for the presence of fV/fVa. The fV antigen was increased in exudative pleural fluids, in comparison with transudates. However, the specific activity of fV antigen present in exudates was significantly less than that observed for the lower concentration of antigen present in transudate and could not be activated to the same degree by thrombin. Immunoblots of fV antigen in exudates indicated that fV was partially cleaved and inactivated by unidentified proteases. We conclude that although fV is present in pleural fluid, it may be present in a degraded form, which may partially account for a lack of thrombin-generating capacity in these pleural fluids. The presence of fV does not necessarily correlate with pleural loculation.
authors.affiliation: Department of Medicine, Temple School of Medicine, Philadelphia, PA 19140.
authors.forename: E G
authors.initials: EG
authors.lastname: Wyshock
authors.forename: S
authors.initials: S
authors.lastname: Idell
authors.forename: R W
authors.initials: RW
authors.lastname: Colman
mesh_terms: D001779:Blood Coagulation Factors / Q000378:metabolism; D004653:Empyema / Q000503:physiopathology; D005165:Factor V / Q000032:analysis / Q000737:chemistry / Q000502:physiology*; D005337:Fibrin / Q000378:metabolism; D005341:Fibrinolysin / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D015151:Immunoblotting; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008175:Lung Neoplasms / Q000503:physiopathology; D008970:Molecular Weight; D010996:Pleural Effusion / Q000503:physiopathology*; D013917:Thrombin / Q000378:metabolism
chemical_list: D001779:Blood Coagulation Factors; D005165:Factor V; D005337:Fibrin; D007770:L-Lactate Dehydrogenase; D013917:Thrombin; D005341:Fibrinolysin; D005947:Glucose