Dynamic CD177/CD10 ratio for infection diagnosis and mortality risk stratification in critically ill patients: a prospective cohort study.

BACKGROUND: Two crucial needs persist in delivering effective critical care: reliable differentiation of infectious vs non-infectious systemic inflammation and detection of impending sepsis before the occurrence of organ dysfunction. This prospective cohort study evaluates the clinical utility of the polymorphonuclear neutrophil (PMN) biomarker CD177/CD10 ratio to differentiate and monitor infections. METHODS: A total of 219 healthy volunteers and 145 patients were assigned to four clinically defined groups: healthy controls (HC), non-infectious inflammation (NI), non-septic infection (NS-I), and sepsis (S). Serial flow cytometric analysis of CD177 and CD10 expression in PMNs was conducted with longitudinal monitoring. Diagnostic efficacy was standardised against conventional biomarkers and organ dysfunction indices. A dynamic CD177/CD10 ratio-based subtyping system (rising/declining/stable pattern) was established for prognostic stratification. FINDINGS: The CD177/CD10 ratio exhibited superior diagnostic performance in infection identification. At a cut-off point (CFP) of 6.07, the area under the curve (AUC) value of the ratio to differentiate NS-I from S was 0.92, exceeding those of CRP (0.85) and PCT (0.85). Notably, this biomarker effectively differentiated NI (CFP = 0.67, AUC = 0.79) from NS-I (CFP = 0.98, AUC = 0.71). The dynamic CD177/CD10 ratio-based subtyping system showed robust prognostic efficacy: patients with the rising subtype exhibited a 7-day mortality rate of 62.5%, while those with decreasing and stable subtypes demonstrated survival rates of 85% and 92.59%, respectively. INTERPRETATION: The CD177/CD10 ratio can facilitate infection-specific differentiation and real-time therapeutic monitoring by quantifying the dynamic equilibrium between the extent of neutrophil activation and maturation. However, the CD177/CD10 ratio still requires validation through a multi-centre trial to confirm the generalisability of the established diagnostic and prognostic thresholds. FUNDING: National Natural Science Foundation of China (No. U21A20370), Natural Science Foundation of Jiangsu Province (BK20240382), Science and Technology Innovation Project of Suzhou (SYW2024116).