Early Inflammatory-Immune Stratification and Precision Glucocorticoid Intervention in Acute Respiratory Failure Induced by Community-Acquired Pneumonia

This study is part of the National Major Science and Technology Project for the Prevention and Control of Emerging and Major Infectious Diseases. It integrates existing multicenter cohorts (including healthy individuals, non-infectious ARF, mild CAP, and CAP-ARF patients) and establishes a prospective, standardized glucocorticoid intervention cohort for bacterial CAP-ARF. Eligible patients (age ≥18, admitted to ICU ≤48 hours, meeting bacterial pneumonia and severe ARF criteria) are treated with methylprednisolone based on initial oxygenation index (PFR ≤150 mmHg: 1 mg/kg/d; PFR \>150 mmHg: 0.5 mg/kg/d). Dosing is adjusted at day 4 based on clinical response (improvement in oxygenation and SOFA score), with a total treatment duration of 7 days. Multimodal data-including clinical information, inflammatory/immune biomarkers, chest CT imaging, and multi-omics sequencing (transcriptomics, proteomics, metabolomics)-are collected at multiple timepoints (baseline, day 4, day 8). The database will support the analysis of immune-inflammatory profiles, identification of glucocorticoid-responsive subgroups, and development of precision intervention strategies for CAP-ARF.