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

Background Till now, salivary C-reactive protein (CRP), mean platelet volume (MPV), and neutrophil-lymphocyte ratio (NLR) have not been studied as markers for diagnosis of neonatal sepsis. Objectives To assess the applicability of salivary CRP, MPV, and NLR as diagnostic markers in preterm neonates with neonatal sepsis. Patients and methods A case–control study was conducted on 184 newborns from the neonatal ICU at Menoufia University Hospital and Qwesna General Hospital from 2021 to 2022. All selected newborns were divided into group I, which included 92 neonates diagnosed as having neonatal sepsis, and group II, which included 92 apparently healthy neonates. Full history taking; thorough clinical examination; laboratory investigations such as complete blood count, leukocyte count, platelet number, NLR, platelet-lymphocyte ratio, serum CRP, salivary CRP, and blood culture; and radiological investigation such as chest radiograph and cranial ultrasound were done. Results Salivary CRP, MPV, and NLR were significantly increased in the case group than the control group. The cutoff values of MPV, NLR, and salivary CRP were 8.4, 1.87, and 8.0, respectively, with sensitivity of 82.6, 97.8, and 98.9%, respectively, and specificity of 97.8, 98.9, and 100%, respectively, for detection of neonatal sepsis. Conclusion Salivary CPR, MPV, and NLR were significantly increased in neonatal sepsis than healthy neonates. However, platelet-lymphocyte ratio was not significant in neonatal sepsis.