Tumor necrosis factor alpha and high sensitivity C-reactive protein in diagnosis of exudative pleural effusion

Differentiation between exudative and transudative pleural effusions is the initial step in assessment of pleural effusion. The aim of this study was to determine whether high sensitivity C-reactive protein (hsCRP) and tumor necrosis factor α (TNFα) are diagnostic utilities for exudative pleural effusion. This experimental study assessed 79 patients with pleural effusion who underwent diagnostic evaluations at Imam Reza hospital, Mashhad, Iran in 2009-2010. The complete biochemical analysis of pleural fluid, pleural fluid culture, and pathological examination of pleural fluid and tissue were performed. Moreover, hsCRP and TNFα concentrations were measured in pleural fluid samples. The data was analyzed by student's t-test and Mann-Whitney test. According to Light's criteria, 50 patients (63.30%) had exudative effusions while 29 subjects (36.70%) had transudative effusion. The pleural fluid concentrations of hsCRP and TNFα were significantly higher in the exudative group than the transudative group (p < 0.05). At a cutoff value of 5 mg/L for hsCRP, the results showed 94% sensitivity and 96.6% specificity. Regarding TNFα, a cutoff value of 12.9 ng/dl represented 96% sensitivity and 93% specificity. HsCRP and TNFα levels may be considered as beneficial diagnostic factors for detecting exudative effusion in patients with pleural effusion.