Evaluation of ferritin, interleukin-6, interleukin-8 and tumor necrosis factor alpha in the differentiation of exudates and transudates in pleural effusions

In an attempt to define diagnostic criteria for the differentiation of pleu ral exudates from transudates, we measured ferritin (FER), interleukin-6 (I L-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) in p leural effusions and blood serum in 84 consecutive patients with pleural ef fusions of various etiologies. Concentrations of FER, IL-8 and TNF-alpha we re significantly higher in serum and pleural effusion in patients with exud ates than in patients with transudates. Serum concentrations of IL-6 were n ot significantly increased in pleural exudate patients (9.78 +/- 17.12 fmol /L) compared to transudate patients (4.05 +/- 2.33 fmol/L), while significa nt differences were found between pleural exudates and transudates (p<0.001 ). Increased levels of FER were found in serum and pleural effusion of canc er patients in comparison to non cancer patients (p<0.001 and p<0.001, resp ectively). Serum concentrations of IL-6, IL-8, and TNF-alpha were not signi ficantly ina eased in cancel compared to non-cancel patients, while increas ed concentrations of IL-6 and IL-8 were found in pleural fluid of patients with cancer in comparison to non-cancer patients. Finally/ no statistically significant differences were found in serum and pleural TNF-alpha concentr ations among patients with cancer and patients with non-cancer effusion. We conclude that FER, IL-6, IL-8 and TNF-alpha concentrations in pleural effu sions are useful markers in differentiating exudates from transudates.