Background: The aim of this study is to investigate the diagnostic value of cerebrospinal fluid (CSF) and serum levels of the soluble form of triggering receptor-1 expressed on myeloid cells (sTREM-1) in neonatal meningitis. Methods: Serum sTREM-1 levels were measured in all neonatal sepsis patients at the start of antibiotic therapy and the 48th hour of treatment. At the beginning of antibiotic therapy, CSF samples were collected for sTREM-1 measurements. Control CSF samples were also collected from the patients with meningitis at the 48th hour of treatment. Results: A total of 77 preterm (50) and term (27) patients with neonatal sepsis were included in the study. There was no significant difference between the CSF sTREM-1 levels of patients with and without meningitis. The CSF sTREM-1 levels of preterm infants with meningitis decreased significantly after treatment (p = 0.038). Although the CSF/serum sTREM-1 ratios tended to increase in babies with meningitis, no significant difference was found between the groups. CSF/serum sTREM-1 ratios (mean ± SD) were 1.42 ± 0.91 and 1.14 ± 0.85 in preterm babies with and without meningitis and 1.15 ± 0.97 and 0.97 ± 0.55 in term babies with and without meningitis, respectively. Conclusions: Serum and CSF sTREM-1 levels increase in patients with neonatal sepsis. CSF s-TREM-1 levels decrease after treatment in preterm infants with meningitis.
