Infectious pleural effusions can be identified by sTREM-1 levels

SummaryBackground and objectiveConventional methods to establish pleural infection are time-consuming and sometimes inadequate. Biomarkers may aid in making rapid diagnosis of infection. In an observational study we evaluated and compared the diagnostic value of pleural fluid levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), C-reactive protein and procalcitonin in intensive care patients with pleural effusions.MethodsThirty-six patients with de novo pleural effusions were included and 20 patients with pleural effusions after cardiothoracic surgery and 20 patients with pleural effusions after esophagus surgery acted as controls. Levels of sTREM-1, C-reactive protein and procalcitonin were measured in pleural effusions.ResultsLevels of sTREM-1 were highest in empyemas, followed by infectious exudates. Levels of sTREM-1 were low in transudates and non-infectious exudates. C-reactive protein levels were highest in exudates and empyemas, while procalcitonin levels were highest in exudates. Pleural fluid with positive culture results contained higher sTREM-1 and C-reactive protein levels as compared to samples with negative culture results. A cut-off level of 50 pg/ml sTREM-1 yielded a sensitivity of 93% and a specificity of 86%, while these were 87% and 67% respectively for a cut-off value of 7.5 μg/ml C-reactive protein, and 60% and 64% respectively for a cut-off value of 0.15 ng/ml procalcitonin.ConclusionsTREM-1 is superior to C-reactive protein and procalcitonin in detecting infection.