Introduction
Severe community-acquired pneumonia (SCAP) represents a critical global health challenge,1 associated with significant morbidity and mortality even with modern antimicrobial therapies and critical care support.2,3 Clinical deterioration typically manifests within 24–72 hours post-admission,4 which underscores the importance of early prognostic stratification to guide intensive monitoring and targeted interventions.5 Existing severity assessment tools such as CURB-65 (confusion, urea, respiratory rate, blood pressure and 65 years of age), Pneumonia Severity Index (PSI), and the Quick Sepsis-related Organ Failure Assessment (qSOFA), while clinically useful, demonstrate limited discriminative capacity for predicting SCAP-specific outcomes.6,7 Biomarkers such as lactate dehydrogenase (LDH), C-reactive…