Noninvasive salivary biomarkers (PTX3, calprotectin, and IL-8) for early-onset neonatal pneumonia: case-control differences and exploratory discrimination

Noninvasive salivary PTX3, calprotectin, and IL-8 are substantially elevated in early-onset neonatal pneumonia and mirror systemic inflammation. The three-marker panel showed near-excellent discrimination vs. healthy controls and modest enrichment for culture-positive bacteremia, suggesting value as an adjunct to bedside assessment in this case-healthy-control setting. Performance in neonates with non-infectious respiratory distress should be validated in prospective cohorts.