Salivary C-reactive protein, mean platelet volume and neutrophil lymphocyte ratio as diagnostic markers for neonatal sepsis

Abstract Objective: To assess the applicability of salivary C-reactive protein, mean platelet volume, neutrophil-lymphocyte ratio, and platelet lymphocyte ratio in the 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. Serum and salivary C-reactive protein concentrations were measured by enzyme-linked immunosorbent assay while mean platelet volume, neutrophil-lymphocyte ratio, and platelet lymphocyte ratio were measured by automated blood cell counter. Results: This study showed statistically significant difference of mean salivary C-reactive protein between septic neonates and controls (12.0 ± 4.6 ng/L vs. 2.8 ± 1.2 ng/L) respectively. At a cut-off point of 3.48 ng/L, salivary C-reactive protein showed 94.3% sensitivity and 80% specificity. Salivary C-reactive protein also showed good predictive accuracy for predicting elevated serum C-reactive protein values in septic neonates. Mean platelet volume and neutrophil-lymphocyte ratio showed significant difference between septic neonates and controls (10.2 ± 1.2 fL vs.8.0 ± 0.5 fL; 2.9 ± 1.7 vs. 1.6 ± 0.4, respectively). At a cut-off point of 10.2 fL, mean platelet volume presented 80% sensitivity and specificity. At a cut-off point of 2.7, neutrophil-lymphocyte ratio presented 80% sensitivity and 57.1% specificity. Conclusion: This study provides support for further studies on the usefulness of salivary C-reactive protein, mean platelet volume, and neutrophil-lymphocyte ratio as diagnostic markers for neonatal sepsis.