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Background Blood eosinophil counts are increasingly used to guide corticosteroid therapy in stable COPD, but their role in acute exacerbations requiring non-invasive ventilation (NIV) remains unclear. Identifying biomarkers predictive of NIV need could inform earlier interventions and improve outcomes.Aim To assess whether admission blood eosinophil levels differ between patients with acute COPD exacerbations who require NIV and those who do not.Methods A retrospective case-control audit was conducted at a single UK centre in 2024–2025. Thirty-three patients were included: 18 required NIV (NIV group), and 15 did not (control group). Groups were matched for age and smoking status. Admission blood eosinophil counts (within 6 hours) were compared. Additional data included systemic steroid use and prior admissions.Results All patients were on optimised inhaler regimens, with similar smoking status, comorbidities, and inhaler use across groups. Systemic corticosteroid use, common in both groups before or during admission, likely affected eosinophil counts, potentially masking baseline inflammation. Although the control group had a slightly higher average number of hospital admissions in the past year, the clinical relevance is unclear.Abstract P152 Table 1 Parameter NIV (n=18) Control (n=15) Mean eosinophil count (×109/L) 0.144 0.153 Median eosinophil count (×109/L) 0.10 0.20 Eosinophils <0.1 ×109/L (%) 39 33b Eosinophils ≥0.3 ×109/L (%) 22 27 Systemic steroid use (%) 83 87 Mean admissions in past year 2.2 2.7 Conclusions Lower eosinophil levels were more frequent among patients requiring NIV, suggesting a possible association with a neutrophilic, steroid-insensitive phenotype. While not statistically significant, admission eosinophil count may serve as a rapid, accessible tool to aid early risk stratification. Larger prospective studies are needed to validate its predictive utility.