LAUSR

Obstructive asthma in non-smokers (NSA), obstructive asthma in smokers (SA), COPD and eosinophilic COPD (COPDeo) are different forms of COAD. Objectives: To quantify systemic inflammation markers (IL6, IL8, TNFα), T2-related cytokines (IL5 and IL13) and IL17 among different forms of COAD, their utility in distinguishing between them and their role in predicting a T2-high inflammatory pattern. Methods: Cross-sectional study of adults with a post-bronchodilator FEV1/FVC 3% or blood Eos>300 UI/mcl. Cytokine concentrations were determined in blood (Milliplex, Merck Millipore®). Results: Sixty-five COPDeo, 44 SA, 89 COPD, and 94 NSA were included. Serum levels of IL5 and IL13 were higher in NSA compared to COPD: 2.09 (0.61-3.57) pg/ml vs 1.11 (0.12-2.42) pg/ml; (p=0.03) and 2.98 (0.23-7.63) vs 1.25 (0.23-5.31) pg/ml; (p=0.35) respectively. IL8 was elevated in COPD [9.45 (6.61-13.12) pg/ml], COPDeo [9.68 (6.25-12.98)] and SA [9.54 (6.40-14.20)] compared to asthma [7.03 (4.69-10.44)]. IL17 was not different between groups. The diagnostic capacity of each single cytokine (or cytokine combinations) to predict a particular form of COAD was poor (AUC Conclusions: T2 cytokines values were higher in NSA than in COPD, with intermediate values in COPDeo and SA, whereas IL-8 was elevated in COPD, COPDeo and SA in comparison to asthma. These cytokines (alone or combined) lacked enough capacity to distinguish between COAD categories and to predict T2-high pattern.