Soluble Triggering Receptor Expressed on Myeloid Cells-1 as a marker to differentiate septic from aseptic meningitis in children: comparison with procalcitonin and C-reactive protein

Background: Differentiating between septic and aseptic meningitis remains a challenge. Procalcitonin (PCT) was suggested by many researchers as a sensitive marker for early diagnosis of septic meningitis but with varying discriminative power. Triggering receptor expressed on myeloid cells-1 (TREM-1), a neutrophil and monocyte receptor, is up-regulated during infection with potential role during sepsis. Objectives: The aim of this study was to evaluate the diagnostic accuracy of soluble TREM-1 in comparison to PCT and C-reactive protein (CRP) in early diagnosis of septic meningitis and its usefulness to distinguish between septic and aseptic meningitis in children. Study design: Fifty-one children aged 2 to 162 months identified as possible cases of meningitis were included in this case control study. Beside Gram staining, cultures of blood and cerebrospinal fluid (CSF) and latex agglutination test of CSF, CRP, serum PCT and soluble TREM-1 (sTREM-1) measurement was done on admission, and after 48-72 hours of treatment. Results: Septic meningitis was diagnosed in 16 (44%) of the studied cases. Although patients with septic meningitis had a significant increase in serum sTREM-1 and PCT levels at the time of admission (median, 25.2 ng/ml and 79.1ng/ml, respectively) in comparison with patients with aseptic meningitis (4.6 ng/ml and 0.7 ng/ml, respectively) and control group (4.1 ng/ml and 0.3 ng/ml, respectively) (p < 0.0001), sTREM-1 showed significantly higher sensitivity (93.7%) and specificity (94.3%) in the early prediction of sepsis with an area under the Receiver Operator Characteristic (ROC) curve (95% CI) of 0.94 (0.84 - 0.99) at a cutoff value of 12.4 ng/ml. Moreover, sTREM-1 but not PCT or CRP concentration was significantly lower (P=0.007) at admission in patients with poor outcome than in those with good prognosis. Conclusions: Both serum PCT and sTREM-1 are valuable in early distinguishing septic from aseptic meningitis in children but with markedly higher diagnostic discriminatory power for sTREM-1. Moreover, sTREM-1 has a significant value in predicting the prognosis of cases with septic meningitis.