Assessment of neutrophils and lymphocytes ratio (NLR) association with mortality in acute COPD exacerbation

<bold>Introduction:</bold> NLR are related to COPD disease physiopathology and the inflammatory response perpetuation. <bold>Objective:</bold> To evaluate the association of NLR and mortality rate during and after one year of hospitalization in COPD patients. <bold>Methods:</bold> Retrospective cross-sectional study with medical records in 2019-2023. We collected demographic characteristics, exacerbation history, spirometry values, length of stay and mortality rate during and after 1 year of hospitalization. We used the first day of hospitalization haemogram. Different NLR cut points from literature were used to verify the association with mortality, and we performed a ROC curve to observe the sensibility and sensitivity of the NLR in mortality. <bold>Results:</bold> 252 hospitalized patients were classified as respiratory, but only 80 had acute COPD exacerbation (age:70.9±10.6 years, 57.5% female). The value of neutrophils was 10.064±10.473, lymphocytes 2.244±3.734, NLR 9.7±10.9. We observed 25 deaths, 6 occurred during the hospitalization and 19 after discharge in 1 year. We did not find statistically significant difference in spirometric values, eosinophils, neutrophils, lymphocytes, leukocytes and LNR between survival and death groups. The mortality rate during or one year after hospitalization had no statistical difference between groups, using the literature cut point 2.88 (during hospitalization p=0.61/ after 1 year p=1.0) and 4.38 (p=0.56/p=1.0). Considering ROC curve analysis, we identified a NLR cut point: 12.2 with 82% specificity and 20% of sensibility to be associated with 1 year death (AUC:0.52). <bold>Conclusion:</bold> In this sample, we could not observe association between NLR and mortality in hospitalized COPD patients.