Diagnostic value of procalcitonin and C-reactive protein in differentiation between some benign and malignant pleural effusions

Pleural effusion is relatively common clinical condition that requires differential diagnosis. It is defined as collection of fluid in pleural space. Pleural effusion is often diagnostic dilemma for the physician. The aim of the study was to assess the procalcitonin (PCT) and C-reactive protein (CRP) levels in serum and pleural fluid to evaluate their usefulness in the differentiation among benign and malignant pleural effusions. This study was conducted in Chest Department, Tanta University Hospital, it included 54 adult patients with pleural effusions of different etiologies, 8 transudative effusion, 14 para-pneumonic effusion, 14 tuberculous effusion and 18 malignant effusion. We measured serum and pleural procalcitonin and C-reactive protein by ELISA. The mean serum and pleural fluid procalcitonin (PCT) levels in parapneumonic effusions were significantly higher compared with transudative, tuberculous and malignant pleural effusions p < 0.05. A significant positive correlation between serum and pleural fluid PCT levels was observed in the studied groups. The mean serum and pleural fluid CRP concentration were significantly lower in malignant and transudative pleural effusion than tuberculous and para-pneumonic effusion p < 0.05. Significant positive correlation between serum and pleural fluid CRP levels was observed in the studied groups. Procalcitonin levels in serum and pleural effusion were significantly lower in malignant effusion compared to para-pneumonic pleural effusion and CRP levels were significantly lower compared to other types of exudative pleural effusion.