Pleural ELFA D-dimer assay: A surrogate marker for malignant pleural effusion

BackgroundMalignant pleural effusion is associated with enhanced fibrinolysis. However, no data are available concerning the precise role of pleural D-dimer assay in pleural effusion. We therefore assessed the role of pleural D-dimer assay in predicting malignant pleural effusion.Patients and MethodsA prospective laboratory investigation was conducted in a tertiary care teaching hospital. The study included consecutive patients with pleural effusion who presented at the Pulmonary Department between November 2009 and May 2010. Blood and pleural D-dimer levels were measured by Enzyme Linked Fluorescent assay (ELFA). The results were correlated with the clinical, laboratory, and radiological findings, and with the final diagnosis of the pleural fluid.ResultsA total of 103 patients with pleural effusion were included in the study. The Pleural ELFA D-dimer results were found to be positively correlated with pleural etiology of malignancy (p = 0.0001). Pleural etiology was also correlated with pleural LDH, pleural protein, pleural PH, pleural glucose, pleural and blood CRP, but not with ADA. In a binary logistic regression, only the pleural ELFA D-dimer assay was a significant predictor of the malignant pleural effusion (odds ratio 1.007; 95% confidence interval 1.002-1.012; p = 0.007). The area under the receiver operating characteristics curve for malignancy was 0.79. A D-dimer level of 146 mg/ml had a sensitivity of 82% and a specificity of 74%.ConclusionsWe found high D-dimer levels among malignant pleural effusion. D-dimer might be useful as a simple, noninvasive, surrogate marker for malignant pleural effusion.