Role of interleukin-6 in diagnosis of pleural effusion

To determine the level of interleukin-6 (IL-6) in both serum and pleural fluid in order to evaluate the diagnostic utility of IL-6 in differentiation between different types of pleural effusion. Pleural effusion is a relatively common clinical condition. It is often diagnostic dilemma for the physician. Interleukin-6 (IL-6) has multiple functions on various cells and tissues. It is often used as a marker for systemic activation of pro-inflammatory cytokines. This study was conducted on 40 patients of pleural effusion, they were selected from Al-Mahalla Chest Hospital in the period between October 2012 and May 2013. All patients were subjected to detailed clinical history, thorough clinical examination, plain chest-X-ray (postero-anterior and lateral views), blood sample for: Complete blood picture (CBC), erythrocyte sedimentation rate (ESR), liver functions, renal functions and serum and pleural fluid (LDH, protein and IL-6) by ELISA. Serum and effusion IL-6 could differentiate between exudate transudate as it increased in exudate than transudate. In the present study there was higher concentration of IL-6 in the serum and pleural effusion of parapneumonic effusion than malignant and tuberculous exudative pleural effusion and higher concentration in malignant than tuberculous effusion. Effusion IL-6 could be used to differentiate between exudate and transudate and serum IL-6 could be used as an alternative non invasive method for differentiation between exudates and transudate as there was a significant positive correlation between serum IL-6 and effusion IL-6.