The following is a summary of “Bacterial load and related innate immune response in the bronchi of rapid decliners with chronic obstructive pulmonary disease,” published in the August 2023 issue of Pulmonary by D’Anna, et al.
Identifying and characterizing COPD patients with a rapid decline in lung function is essential for prognosis and treatment. A previous study reported impaired humoral immune response in rapid decliners. For a study, researchers sought to determine the microbiota associated with innate immune host response markers in COPD patients with rapid lung function decline.
A cohort of COPD patients monitored for at least 3 years (mean ± SD: 5.8 ± 3 years) for lung functional decline was included. The microbiota composition and related markers of immune response were measured in bronchial biopsies of patients with different rates of lung functional decline. The patients were categorized into three groups based on the rate of decline in FEV1%: no decline (FEV1% decline ≤20 ml/year, n = 21), slow decline (FEV1% decline >20 ≤ 70 ml/year, n = 14), and rapid decline (FEV1% decline >70 ml/year, n = 15). Microbiota analysis was performed using qPCR, while cell receptors and inflammatory markers were assessed using immunohistochemistry.
The study found that Pseudomonas aeruginosa and Streptococcus pneumoniae were increased in COPD patients with rapid lung function decline compared to those with a slow decline. S. pneumoniae was also increased in rapid decliners compared to non-decliners. In all COPD patients, S. pneumoniae (copies/ml) showed positive correlations with pack-years consumption, lung function decline, toll-like receptor 4 (TLR4), nucleotide-binding oligomerization domain-containing protein 1 (NOD1), NOD2 scored in bronchial epithelium, and NOD1/mm in the lamina propria.
The findings suggested an imbalance in the microbiota composition in COPD patients with rapid lung functional decline associated with the expression of related cell receptors in all COPD patients. The results had potential implications for prognostic stratification and treatment approaches in COPD patients.