Clinical significance of the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in acute exacerbations of COPD: present and future

Abstract

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a leading cause of hospitalisation and death in COPD patients. In addition to the identification of better strategies to prevent AECOPD, there is an intense focus on discovering novel markers of disease severity that enhance risk stratification on hospital admission for the targeted institution of aggressiveversussupportive treatments. In the quest for such biomarkers, an increasing body of evidence suggests that specific indexes derived from routine complete blood counts,i.e.the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR), can significantly predict adverse outcomes in AECOPD. This narrative review discusses the current evidence regarding the association between the NLR and the PLR on admission and several clinical end-points (need for invasive ventilation, noninvasive mechanical ventilation failure, admission to an intensive care unit, pulmonary hypertension, length of hospitalisation, and mortality) in AECOPD. Future research directions and potential clinical applications of these haematological indexes in this patient group are also discussed.

Predictive role of neutrophil‐percentage‐to‐albumin, neutrophil‐to‐lymphocyte and eosinophil‐to‐lymphocyte ratios for mortality in patients with COPD: Evidence from NHANES 2011–2018

“…A previous narrative review discussed the relationship between NLR and the PLR on admission and several clinical endpoints in COPD 28 . That narrative review also demonstrated that NLR is a simple and inexpensive marker of inflammation that has been increasingly studied in several disease states, including COPD, and appears to be a promising predictor of mortality in COPD patients.…”

Associations of diabetes, prediabetes and diabetes duration with the risk of chronic obstructive pulmonary disease: A prospective UK Biobank study

“…COPD is a chronic disease, followed by a slowly progressive natural course that can be accelerated by acute exacerbation, which was the leading cause of death in COPD patients. 50 Given that the acute exacerbation of COPD can be reversible by urgent or hospital treatment, COPD-specific death cases among COPD patients may be limited, which was insufficiently powered to find statistical significance. Besides, COPD patients with prediabetes, diabetes and longer diabetes duration showed higher HRs for COPD-specific death, but the result with wide confidence intervals crossing the null hypothesis suggests there is insufficient statistical power to provide significant conclusions.…”

“…One possible explanation for this is that the number of COPD‐specific death cases was insufficient to detect significant statistical power. COPD is a chronic disease, followed by a slowly progressive natural course that can be accelerated by acute exacerbation, which was the leading cause of death in COPD patients 50 . Given that the acute exacerbation of COPD can be reversible by urgent or hospital treatment, COPD‐specific death cases among COPD patients may be limited, which was insufficiently powered to find statistical significance.…”

The Effect of a Three-Level Remote Alliance on Critical Care in Grassroot Areas: A Multi-Center, Retrospective Study

“…11 The clinical condition known as acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is characterized by a sudden deterioration of respiratory symptoms and airway function. 12 …”