Background: When exacerbation of chronic obstructive pulmonary disease (AECOPD) occurs frequently, patients have high levels of airway and systemic inflammation and a poor quality of life. This study compared the nature and course of systemic and airway inflammation during AECOPD between patients who experienced frequent exacerbations and those with non-frequent exacerbations.
Material and Methods: Consecutive hospitalized patients with AECOPD were recruited and divided into 2 groups according to the frequency of AECOPD they had experienced in the previous year. Frequent exacerbators (defined as 2 or more AECOPD in the previous year) and non-frequent exacerbators (defined as zero or 1 AECOPD in the previous year). Inflammatory (interleukin 6, interleukin 8, myeloperoxidase, and C-reactive protein) and clinical (dyspnea, COPD assessment test (CAT), and peak expiratory flow) indices were assessed on the day of admission before starting therapy, day 7 of treatment, the day of planned discharge (day 10–14), and 8 weeks after discharge.
Results: We analyzed data from 135 patients; 78 (57.8%) were non-frequent exacerbators and 57 (42.2%) were frequent exacerbators. In both groups, the inflammatory and clinical indices at day 7, the day of planned discharge (day 10–14), and 8 weeks were significantly improved compared to those at admission. Frequent exacerbators had a smaller reduction in their inflammatory indices and CAT scores between exacerbation onset and all the other time points compared with infrequent exacerbators.
Conclusions: Frequent exacerbators have a reduced response to treatment of AECOPD in terms of inflammatory indices and quality of life.

Keywords: Bronchitis - physiopathology, C-Reactive Protein - metabolism, China, Dyspnea - pathology, Inflammation - physiopathology, Interleukin-6 - metabolism, Interleukin-8 - metabolism, Lung Diseases, Obstructive - physiopathology, Peak Expiratory Flow Rate - physiology, Peroxidase - metabolism, Prospective Studies, Quality of Life, Recurrence, Statistics, Nonparametric, Time Factors