Evaluation of biomarkers sTREM-1, procalcitonin and C reactive protein in the diagnosis of pleural infection.

UNLABELLED: Diagnosis of complicated parapneumonic pleural effusion (CPPE), empyema and uncomplicated parapneumonic pleural effusion (UPPE) is vital in therapeutic management.

OBJECTIVE: To measure the pleural fluid concentrations of soluble triggering receptor expressed on myeloid cell-1 (sTREM-1), procalcitonin (PCT) and C reactive protein (CRP) to provide information for diagnosing and discriminating between CPPE and UPPE.

METHODS: Retrospective data analysis from February 2016 to December 2017, focused on pleural fluid analysis of patients with infectious (PPE, empyema and tuberculosis) and non-infectious (malignant and transudates) effusions.

RESULTS: Over 224 pleural fluid samples collected, 29 were empyema, 48 CPPE, 31 UPPE, 35 tuberculous, 47 malignant and 34 transudates. The levels of sTREM-1 and PCT were significantly higher in empyema (3658&#xb1;1474&#x2009;and 1704&#xb1;1027) and CPPE (2651&#xb1;1058&#x2009;and 841&#xb1;667) and lower in transudates (p<0.001). CRP levels were significantly higher in empyema (88.8&#xb1;61.5) and CPPE (83.8&#xb1;42.6) than in other groups (p<0.001), with no difference between them.

CONCLUSION: The study demonstrated higher sTREM-1, PCT and CRP levels in empyema and CPPE and lower levels in transudates. Both sTREM-1 and CRP showed a higher than 70% diagnostic accuracy between infectious and non-infectious pleural effusions and between CPPE and UPPE; however, not superior to LDH pleural fluid levels.