Background: Neonatal sepsis is a major cause of morbidity and mortality in neonatal intensive care units. Neonatal saliva overcomes many of the hurdles associated with neonatal research and offers the investigator a new and exciting non-invasive sample source for exploring neonatal biology. Till now salivary C-reactive protein (CRP), neutrophil / lymphocyte ratio (NLR) and platelets /lymphocytes ratio (PLR) have not been studied as markers of diagnosis in neonatal sepsis.
Objective: To assess the applicability of salivary CRP, mean platelet volume (MPV), NLR and PLR in diagnosis of neonatal sepsis.
Methods: Prospective case control study of 70 full term neonates, 35 with sepsis (20 with proven sepsis and 15 with clinical sepsis) and 35 healthy controls were enrolled. Serum and salivary CRP concentrations were measured by ELISA, while MPV, NLR and PLR were measured by automated blood cell counter.
Results: This study showed statistically significant difference between salivary CRP mean between septic neonates and controls (12.0±4.6 ng/L and 2.8±1.2 ng/L) respectively. At cut- off point 3.48 ng/L salivary CRP showed sensitivity 94.3% and specificity 80%. Salivary CRP showed also good predictive accuracy in predicting elevated serum CRP values in septic neonates. MPV and NLR showed significant difference between septic neonates and controls, (10.2±1.2 fL /8.0 ±0.5 fL), (2.9±1.7, 1.6±0.4) respectively. MPV at cut-off point 10.2 fL has 80 % sensitivity and specificity. NLR at cut-off point 2.7 has 80% sensitivity and 57.1 % specificity.
Conclusion: This is the first study to demonstrate that salivary CRP and NLR are suitable as diagnostic markers in neonatal sepsis. Salivary CRP could be used as a non-invasive marker for diagnosis of neonatal sepsis.