The Relationship Between Comorbidities and Microbiologic Findings in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Abstract

Purpose Data regarding the relationship between microbiologic features and comorbidities in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are limited. The aim of this study was to correlate microbiologic findings with comorbidities in patients with moderate to severe AECOPD. Patients and Methods This multicenter observational study included patients with AECOPD seen at 28 hospitals in South Korea between January 2015 and December 2018, and the data were retrospectively collected. Pathogens were examined in patients with either pulmonary or extrapulmonary comorbidities, and compared to those of patients without comorbidities. The relationship between pathogen type and the number of comorbidities was also evaluated. Results Bacterial infections (178 [37.2%] vs 203 [28.7%], p = 0.002) and co-infections with bacteria and viruses (65 [13.6%] vs 57 [8.1%], p = 0.002) were more prevalent in patients with pulmonary comorbidities. Bacterial pathogens (280 [34.7%] vs 101 [26.7%], p=0.006) were detected at a higher rate in patients with extrapulmonary comorbidities. Previous pulmonary tuberculosis (PTB), bronchiectasis, and diabetes mellitus were risk factors for bacterial infection, and congestive heart failure was a risk factor for bacterial and viral co-infection. As the number of comorbidities increased, the risk of bacterial infection increased considerably. Pseudomonas aeruginosa was more frequently identified in patients with previous PTB (57 [15.3%] vs 59 [7.4%], p < 0.001) and bronchiectasis (33 [19.6%] vs 83 [8.3%], p < 0.001). Conclusion AECOPD patients with comorbidities were more likely to experience infection-related exacerbations compared to those without comorbidities. As the overall number of comorbidities increased, the risk of bacterial infection increased significantly.

Relation between airway cellular and bacterial findings and severity of COPD exacerbations: A multicentric study

“…We did quantitative cultures by the calibrated loop method. The specimen (0.1 ml) was overlaid onto solid media and colony forming unit (CFU) were calculated after 24 hours of incubation [12]. To avoid overestimation of bacterial etiology, we considered that specimens with CFU˂10 4 /ml as colonization and omitted from the research, while specimens with CFU≥10 4 /ml considered as an infection.…”

Bacterial Species and Inflammatory Cell Variability in Respiratory Tracts of Patients with Chronic Obstructive Pulmonary Disease Exacerbation: A Multicentric Study

“…In addition, variations in the distributions of the respiratory microbiota between various populations may be a contributing factor. 12 For example, the predominant isolated organism in one South Korean study 13 and another Ethiopian one 14 was Pseudomonas aeruginosa, while Klebsiella pneumoniae prevailed in an Indian study. 15 It was also noted that isolated organisms may vary between upper and lower respiratory tracts in patients with stable COPD and AECOPD.…”

Respiratory Immune Responses during Infection and Pollution Inhalation

“…A review article by Guo-Parke and colleagues took a different perspective by focusing on the airway epithelium as a major site of anti-viral infection responses and detailed the current insights within the literature to detail the mechanisms of viral evasion and host interferon antiviral defense signaling impairment of the airway epithelium within chronic obstructive pulmonary disease (COPD) patients [ 7 ]. Viral infections were found to significantly impact COPD patient hospitalization and the continued loss of lung function [ 8 ]. Here, the authors also briefly detailed the potential role of the epithelium anti-viral responses against SARS-CoV-2 and the implications of impaired epithelial antiviral responses on therapeutic options [ 7 ].…”