Neutrophil Count Percentage and Neutrophil–Lymphocyte Ratio as Prognostic Markers in Patients Hospitalized for Community-Acquired Pneumonia

Abstract

IntroductionCommunity-acquired pneumonia (CAP) is a common serious infection. This study aimed to evaluate the prognostic utility of neutrophil count percentage (NCP) and neutrophil–lymphocyte ratio (NLR) in patients with CAP. MethodsRetrospective study of hospitalized patients with CAP. Patients had a blood test at admission and 3–5 days after hospitalization (early-stage test). The main outcome variables were 30-day and 90-day mortality. ResultsTwo hundred and nine patients were included. Patients who survived had significant reductions in both NCP and NLR between admission and the day 3–5 blood tests (from 85.8% to 65.4% for NCP and from 10.1 to 3.2 for NLR). Twenty-five patients died in the first 90 days. Patients who died had lower, non-significant reductions in NCP (from 84.8% to 74%) and NLR (from 9.9 to 6.9) and significantly higher early-stage NCP and NLR than those who survived. NCP values higher than 85% and NLR values higher than 10 in the early-stage blood test were associated with a higher risk of mortality, even after multivariate adjustment (HR for NCP: 12; HR for NLR: 6.5). ConclusionNCP and NLR are simple, low-cost parameters with prognostic utility, especially when measured 3–5 days after CAP diagnosis. High NLR and/or NCP levels are associated with a greater risk of mortality at 90 days.