Fibrinogen degradation products in pleural effusions.

This study investigates the diagnostic value of fibrinogen degradation products (FDP) in pleural fluid and serum. Thirty patients with pleural effusions due to a variety of causes were investigated. The concentration of FDP in pleural fluid was significantly higher in patients with malignancy, infection and pulmonary embolus than in patients with congestive cardiac failure. The concentration of FDP in serum was not significantly different between any of the groups. We conclude that estimation of the concentration of FDP in pleural fluid, a simple biochemical procedure, has some value in differential diagnosis of pleural effusion and complements existing tests.