Pleural Fluid Soluble Triggering Receptor Expressed on Myeloid Cells-1 in Complicated and Uncomplicated Parapneumonic Pleural Effusions

Background. Soluble triggering receptor expressed on myeoid cells-1 (sTREM-1) has recently been found to be high in infected pleural fluid (PF). Objectives. Diagnostic accuracy of PF sTREM-1 for differentiating uncomplicated parapneumonic effusions (UPPEs) from complicated parapneumonic effusions (CPPEs) was evaluated prospectively. Methods. Serum and PF sTREM-1 were measured for 68 patients with parapneumonic and transudative pleural effusion. Results. PF (but not serum) sTREM-1 concentrations were significantly higher in CPPE than in UPPE. Serum and PF sTREM-1 levels were higher in parapneumonic than in transudative groups. PF sTREM-1 had a sensitivity of 85.19% and a specificity of 83.33% at cutoff value of 250.5 pg/mL for differentiating CPPE and UPPE with area under the curve (AUC) of 0.9336. After excluding purulent CPPE cases, sensitivity and specificity became 90.48% and 83.33%, respectively (at the same cutoff value) with AUC of 0.9444. Conclusion. High concentrations of PF sTREM-1 (above 250.5 pg/mL) help to early diagnose and differentiate CPPE from UPPE.