Proinflammatory Cytokines, Transforming Growth Factor-β1, and Fibrinolytic Enzymes in Loculated and Free-Flowing Pleural Exudates

Compared with free-flowing effusions, fibrinolytic activity was depressed in loculated effusions. A higher intensity of pleural inflammation in loculated effusions may enhance the release of TNF-α, IL-1β, and TGF-β1, which may subsequently increase the levels of PAI-1. The imbalance of PAI-1 and tPA in pleural spaces may lead to fibrin deposition and loculation of pleural effusions