Blood eosinophil counts linked to adverse pneumonia events in COPD patients
Patients with a blood eosinophil count below 2% experience more adverse pneumonia events.
Patients with chronic obstructive pulmonary disease (COPD) who had lower blood eosinophil counts typically had more pneumonia events than patients with higher counts, according to research published in Lancet Respiratory Medicine.
Ian D. Pavord, FMedSci, Respiratory Medicine Unit, Nuffield Department of Medicine, University of Oxford, United Kingdom, and colleagues conducted a meta-analysis of 10 randomized, double-blind trials conducted between 1998 and 2011, with a total of 10,861 patients with COPD. All studies included an inhaled corticosteroid arm, a control arm, and pre-randomization measurements of blood eosinophil counts.
Of the patients included, 4043 had baseline blood eosinophil counts of less than 2%; 6818 patients had baseline blood eosinophil counts of 2% or more. Among patients with counts lower than 2%, 3.7% had 1 or more pneumonia adverse events, compared with 3.2% among patients with counts of 2% or more. Patients treated with inhaled corticosteroids experienced pneumonia adverse events in 4.5% and 3.9%, respectively.
“Using 2% baseline eosinophil count as a threshold, patients with COPD with lower blood eosinophil counts had more pneumonia events than did those with higher counts,” said Professor Pavord. “The magnitude of this increased risk was small and should be further explored in large, prospective studies.
“These data should be considered when making treatment decisions, alongside existing evidence that patients with COPD and baseline blood eosinophil counts less than 2% have a poorer response to inhaled corticosteroids.”
- Pavord ID, Lettis S, Anzueto A, et al. Blood eosinophil count and pneumonia risk in patients with chronic obstructive pulmonary disease: a patient-level meta-analysis. Lancet Respir Med. 2016; doi: 10.1016/S2213-2600(16)30148-5