Soluble Triggering Receptor Expressed On Myeloid Cells-1: Role In The Diagnosis Of Pleural Effusions

Background: The currently available diagnostic markers for pleural effusion have a limited role. The soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is a molecule recently reported to play an important role in the myeloid cell mediated inflammatory response, and is up regulated in the body fluid by bacterial or fungal products. This study examined the expression of sTREM-1 in pleural effusion.Methods: Between April 2004 and December 2005, 48 patients with pleural effusions were enrolled in this study. The pleural fluids were taken and analyzed for the total protein, glucose, lactate dehydrogenase (LDH), adenosine deaminase (ADA), and sTREM-1. Bacterial cultures and cytology tests were also performed.Results: The clinical diagnoses were 17 parapneumonic, 14 tuberculous, and 13 malignant effusions. Four patients presented with transudates. The mean ages of the parapneumonic, tuberculous and malignant effusion groups were 57.1 +/- 19.7, 49.5 +/- 18.6, 66.9 +/- 15.5, and 76.0 +/- 18.1. respectively. The level of sTREM-1 expression was significantly higher in the parapneumonic effusions (344.0 +/- 488.7) than in the tuberculous effusions (81.7 +/- 56.6) and malignant effusions (39.3 +/- 19.6). With a cut-off value of 55.4pg/ml, the sensitivity and specificity for a parapneumonic effusion was 70.6% and 74.1%.Conclusion: sTREM-1 expression is significantly higher in parapneumonic effusions, suggesting its potential role as an additional diagnostic marker for pleural effusions.