OBJECTIVES: Chronic obstructive pulmonary disease (COPD)– a progressive lung disease– is the third leading cause of death worldwide, accounting for 3.3 million deaths in 2019. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) previously categorised patient burden and exacerbation risk into Groups A (low risk/low symptoms), B (low risk/high symptoms), C (high risk/low symptoms) and D (high risk/high symptoms). An update in 2023 merged Groups C and D into Group E. However, clinical burden data for these groups, especially for those with type 2 inflammation and high eosinophil levels, were scarce, prompting a focused literature review.
METHODS: Databases such as Embase, MEDLINE, the Cochrane Library and conference abstracts were searched, as well as key websites, including GOLD and the American College of Chest Physicians. The search covered publications from 2012 to 2022.
RESULTS: All relevant articles were finalised for review. More than 80% COPD patients face daily symptoms such as dyspnoea, cough and sputum production. Physical impairments and comorbidity burden were notably higher in GOLD Group D, with three times the number of exacerbations, compared to Group A. Patients in Groups B and D also exhibited higher levels of anxiety and depression. Blood eosinophil counts (≥300 cells/µL) and other type 2 inflammation biomarkers (sputum, fractional exhaled nitric oxide [FeNO], and atopy) were associated with the risk of severe COPD exacerbations. Elevated levels of FeNO were observed in non-smoking COPD patients with an association was reported between FeNO and exacerbations in the preceding 12 months. Patients shifted across GOLD groups due to changing symptoms and exacerbation levels over time.
CONCLUSIONS: This literature review elucidates the clinical burden among COPD patients in different GOLD groups, emphasising the need for improved management strategies. The evidence suggests a correlation between higher eosinophil counts and FeNO levels with exacerbations, providing insights into potential therapeutic targets and prognosis markers.
