Severe Asthma Research - June 2016
Christina E Ciaccio, MD, MSc
Assistant Professor of Pediatrics
University of Chicago Medicine
Comer Children’s Hospital
Chicago, Illinois, United States
Plasma interleukin-6 concentrations, metabolic dysfunction, and asthma severity: a cross-sectional analysis of two cohorts.
A subgroup of patients with severe asthma does not have features of Th2 inflammation and do not respond to Th2 targeted therapy. Obesity is common in patients with severe asthma and is associated with IL-6 related inflammation. In this study, healthy subjects, subjects with non-severe asthma and subjects with severe asthma were compared. IL-6 levels and CRP levels were measured in serum samples and IL-6 levels and IL-6 RNA were measured in induced sputum samples. 93 healthy control participants, 249 non-severe asthma participants, and 387 severe asthma participants were recruited. The severe asthma cohort was older and weighed more than the other groups. 14% of the non-severe asthma subjects and 26% of the severe asthma subjects were IL-6 high. CRP levels were higher in subjects with asthma and highest in IL-6 high asthmatics. IL-6 high subjects also had a significantly higher BMI, a higher prevalence of hypertension, and higher values for systolic blood pressure and blood leukocytes. Asthma exacerbations were more frequent and ACT scores were lower in the IL-6 high subgroups in both asthma cohorts than in the IL-6 low subgroups. Asthma outcomes were also consistently worse in obese IL-6 high asthma patients than in obese IL-6 low asthma patients. These findings suggest that IL-6 may be a mediator of severe disease in a subgroup of asthmatics and identifies a potential target for asthma therapeutics.
Peters MC, McGarth KW, Hawkins GA, Hastie AT, Levy BD et al. Plasma interleukin-6 concentrations, metabolic dysfunction, and asthma severity: a cross-sectional analysis of two cohorts. The Lancet Respiratory Medicine 2016; 4(7): 574-584. (doi:10.1016/S2213-2600(16)30048-0)