An observational study of salivary C-reactive protein as a potential novel non-invasive biomarker of neonatal sepsis

Abstract

Objectives: Serial C-reactive protein (CRP) monitoring helps to rule out and prognosticate sepsis. Small blood volumes in neonates make it difficult for repeated blood draws for serial CRP monitoring. Hence, the need of the hour is a non-invasive method such as CRP estimation in saliva. This study aims to correlate salivary CRP with serum CRP levels and establish the potential clinical utility of salivary CRP in diagnosing neonatal sepsis. Materials and Methods: Twenty-three consecutive neonates diagnosed with clinically suspected sepsis and admitted to the NICU were the study subjects. Demographics such as gestational age and weight at birth, sex and detailed clinical features, and comorbidities were noted. Blood samples for CRP estimation and blood culture were collected as soon as clinical suspicion of sepsis arose. Saliva samples were collected for CRP estimation within 1 h of blood sample collection. The saliva was collected in a 2 mL syringe using low suction. Salivary and serum CRP were estimated by the particle enhanced immunoturbidimetric assay. Results: In our study, the CRP levels in saliva correlated moderately well with CRP levels in serum (Spearman correlation coefficient r = 0.582, P = 0.004). The sensitivity and specificity of salivary CRP to predict a serum level of ≥10 mg/L were observed to be 0.75 and 0.93, respectively. Conclusion: Our study shows the promise of salivary CRP as a potential clinically meaningful biomarker of neonatal sepsis and warrants the need for larger studies to validate the utility of salivary CRP to serially monitor neonatal sepsis.