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The following is a summary of “Cytokine Biomarkers of Exacerbations in Sputum From Patients With Chronic Obstructive Pulmonary Disease: A Prospective Cohort Study,” published in the June 2024  issue of Infectious Disease by Budroni et al.

Researchers conducted a retrospective study investigating how cytokine levels in sputum relate to clinical data to define the characteristics of chronic obstructive pulmonary disease (COPD) exacerbations.

They collected sputum samples from 99 participants in the Acute Exacerbation and Respiratory InfectionS (AERIS) in COPD during both stable disease and exacerbation episodes (936 samples). The 30 cytokines within the samples were analyzed to understand the expression patterns over time (longitudinal expression) and investigated how cytokine levels differed based on disease state (stable vs. exacerbation) and the specific type of exacerbation.

The result showed that among the 30 cytokines measured, 17 were relevant for further analysis. Levels of interleukin (IL)-17A, tumor necrosis factor-alpha (TNF-α), IL-1β, and IL-10 were significantly elevated in sputum during COPD exacerbations compared to stable periods. A statistical model couldn’t reliably differentiate between various stages based solely on cytokine levels. In different types of exacerbation, bacteria-associated exacerbations displayed a distinct pattern, with higher expression of IL-17A, TNF-α, IL-1β, and IL-1α. Additionally, IL-1α, IL-1β, and TNF-α emerged as promising biomarkers for specifically identifying bacterial exacerbations. Principal component analysis revealed that bacteria-associated exacerbations formed a distinct cluster, separate from others.

Investigators concluded that sputum analysis of IL-1α, IL-1β, or TNF-α levels in patients with COPD held promise as a rapid test to identify bacterial exacerbations.

Source: academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiae232/7688011