The Neutrophil-lymphocyte ratio in patients with community-acquired pneumonia

Abstract

Background: Neutrophil-to-lymphocyte ratio (NLR) has emerged as a new marker of inflammation associated with the severity of several respiratory and cardiac diseases. Aim: To investigate the usefulness of NLR as biomarker of Bacterial Community-Acquired Pneumonia (BCAP) severity. Methods: A retrospective study was conducted in a tertiary care hospital in Tunis. Data of adults hospitalized from 2015 to 2017 for BCAP were analyzed. BCAP was defined as the presence of a new infiltrate on chest-X ray associated with one or more suggestive clinical features. White blood cells (WBC) differential count, CRP and NLR were determined before initiation of antibiotics. NLR level was considered high when it was ≥ 3.5. Pneumonia severity (CURB-65 score), clinical characteristics, complications and outcomes were related to the NLR. Results: During the study period, 79 patients with BCAP (mean age=51.6±17.6 years; 56 male, 23 female) were included. NLR increased in 68.4% of patients. Mean NLR value was 8.27±7. NLR level was higher in diabetics and was significantly associated with CRP (p 0.05). Conclusion: NLR seems to predict severity and outcome of BCAP. Further studies are needed to confirm these data.