Vol. 1, Issue 1, Part A (2017)

Background: Pleural effusion, the accumulation of excess fluid in the pleural space, arises from diverse pathological processes. Correctly differentiating between transudative and exudative effusions is critical for identifying underlying etiologies and guiding treatment. While Light’s criteria remain the gold standard for classification, additional biochemical markers such as C-reactive protein (CRP), malondialdehyde (MDA), and uric acid have shown promise in enhancing diagnostic precision.

Aim: To evaluate the role of pleural fluid CRP, MDA, and uric acid in differentiating transudative and exudative pleural effusions and assess their diagnostic utility alongside Light’s criteria.

Methods: This observational analytical study included 75 patients with pleural effusion at Madha Medical College and Hospital (February 2016-February 2017). Patients were classified into transudative or exudative groups using Light’s criteria. Pleural fluid and serum levels of CRP, MDA, and uric acid were measured and compared between groups. Statistical analysis included t-tests for mean differences and Pearson correlation for association strength, with p<0.05 considered significant.

Results: Exudative effusions showed significantly elevated pleural CRP (mean 19.69±3.81 mg/L) and MDA (mean 649.52±84.69 nmol/dL) levels compared to transudative effusions (CRP 4.52±1.14 mg/L, MDA 210.03±30.77 nmol/dL; p<0.001). Conversely, pleural uric acid levels were higher in transudates (7.68±0.78 mg/dL) than exudates (4.16±0.96 mg/dL; p<0.001). Strong correlations were observed between MDA and CRP (r = 0.952), MDA and protein (r = 0.874), and negative correlation between MDA and uric acid (r =-0.903).

Conclusion: CRP, MDA, and uric acid in pleural fluid serve as useful adjuncts to Light’s criteria for distinguishing transudative from exudative effusions. Their integration into routine pleural fluid analysis can enhance diagnostic accuracy, particularly in ambiguous or borderline cases, contributing to better patient management.