Diagnostic Value of Pleural Fluid Cholesterol to Differentiate Exudative and Transudative Pleural Effusion

Background: Pleural effusion is a common medical condition with many etiologies. Occasionally, it may represent a mysterious diagnostic issue.Aim: To evaluate the usefulness of pleural fluid cholesterol in differentiating exudative from transudative pleural effusion.Patients and methods: This prospective cross-sectional investigation occurred between June 2023 and April 2024. It involved 80 cases admitted at the Chest Departments (Al-Hussein and Sayed Galal University Hospitals), with clinical and radiological diagnoses of pleural effusion. Cases were separated regarding the underlying cause of pleural effusion into five groups: malignant group (20 patients), tuberculous group (15 patients), para-pneumonic group (15 patients), collagen vascular disease-related group (10 patients), and transudative group (20 patients).Results: According to pleural fluid cellularity and cholesterol distribution, the study groups had statistically significant variances. Considering U/S findings, there were no statistically significant variances among the study groups in pulmonary mass and mediastinal lymphadenopathy. Highly statistically significant differences were detected among the studied groups regarding pleural nodule, consolidation, and septation.Conclusion: Estimating cholesterol levels in pleural fluid is an essential biomarker in the differential diagnosis of exudative versus transudative pleural effusion. Adding other parameters, such as NLR in serum and pleural fluids, could be more helpful in the same mission.