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±1474 and 1704±1027) and CPPE (2651±1058 and 841±667) and lower in transudates (p<0.001). CRP levels were significantly higher in empyema (88.8±61.5) and CPPE (83.8±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.