The diagnostic value of pleural effusion/serum ratio of carcinoembryonic antigen and pleural effusion/serum ratio of interferon-γ in classification of pleural effusion.

Background: Distinguishing between different types of pleural effusions (PEs) is crucial for clinical diagnosis and treatment. This study evaluates the diagnostic value of carcinoembryonic antigen (CEA) and interferon-gamma (IFN-γ) levels in PE and serum, as well as the PE/serum ratios of these markers, in classifying PE.

Methods: We retrospectively analyzed 99 patients with PE, categorizing them into malignant pleural effusion (MPE), tuberculous pleural effusion (TPE), and benign PE groups. Levels of CEA and IFN-γ in PE and serum were quantified and their ratios were calculated. Diagnostic performance was assessed using receiver operating characteristic analysis, focusing on the area under the curve (AUC) to determine the efficacy of these biomarkers.

Results: Significantly elevated levels of CEA in PE and serum were observed in the MPE group compared to the benign and TPE groups, with the PE/serum CEA ratio offering substantial diagnostic value (AUCs: PE = 0.843, serum = 0.744). Conversely, IFN-γ levels in PE and serum were markedly higher in the TPE group, demonstrating notable diagnostic accuracy (AUCs: PE = 0.970, serum = 0.917).

Conclusion: Both CEA and IFN-γ demonstrate high clinical utility in differentiating between MPE and TPE. The PE/serum ratio of these biomarkers enhances diagnostic accuracy, potentially facilitating earlier and more accurate therapeutic interventions.