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

Introduction: Community-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.

Methods: Retrospective 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.

Results: Two hundred and 9patients 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).

Conclusion: NCP 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.