Abstract
OBJECTIVE: This study examined the correlation between changes in peripheral blood neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) before and after treatment, and Exacerbations of Chronic Pulmonary Disease Tool - Patient Reported Outcome (EXACT-PRO) scores in patients with acute exacerbations of COPD (AECOPD), to assess the clinical utility of EXACT-PRO in measuring disease severity. METHODS: Hospitalized patients diagnosed with AECOPD underwent pulmonary function testing, and peripheral blood NLR and PLR levels were recorded before and after treatment. Participants completed the EXACT-PRO, COPD Assessment Test (CAT), and modified Medical Research Council (mMRC) Dyspnea Scale questionnaires. Patients with AECOPD were classified into mild, moderate, and severe groups according to the 2026 GOLD classification criteria. Baseline characteristics were compared across the three groups. Pearson's correlation analysis was performed to evaluate the relationship between changes in NLR, PLR, and EXACT-PRO scores. ROC curves of post-treatment NLR and EXACT-PRO scores were further constructed to evaluate the discriminative performance of NLR, and a scatter plot was used to visually illustrate the correlation between the two variables. RESULTS: After applying the exclusion criteria to the initial cohort of 112 patients, a total of 60 patients with AECOPD were ultimately included in the analysis. According to the 2026 GOLD classification criteria, 13 patients were classified as mild, 29 as moderate, and 18 as severe. Blood samples were collected within 24 hours of hospital admission before treatment and on the day of discharge after treatment. Post-treatment NLR levels showed a statistically significant reduction compared to pre-treatment levels (p < 0.05, 95% CI: 1.12-5.60). A positive correlation was observed between post-treatment NLR levels and EXACT-PRO scores. CONCLUSION: Peripheral blood NLR levels demonstrated potential clinical relevance in patients with AECOPD and may support the development of a simple and effective quantitative tool for assessing disease severity.