We read with interest the retrospective study by Vanetti et al. [1], which evaluated the neutrophil-to-lymphocyte ratio (NLR) in 247 clinically stable patients with chronic obstructive pulmonary disease (COPD) admitted to a pulmonary rehabilitation center. Using receiver operating characteristic analysis anchored to a history of ≥1 severe COPD exacerbation (severe ECOPD) in the previous 12 months, the authors identified an NLR threshold of 2.26 and reported that higher NLR (HNLR; NLR ≥2.26) was associated with a history of ≥1 severe ECOPD in the previous 12 months, greater respiratory impairment, selected comorbidities and systemic markers, and assignment to a higher estimated 10-year cardiovascular risk category.
