The lower airway type-2 cytokine interleukin (IL)-24 is a representative biomarker for united airways in allergic asthma, according to a study published in the Journal of Allergy and Clinical Immunology. Periostin and IL-10 have also shown moderate associations with clinical symptoms and therefore may also serve as proxy biomarkers.
This study included 15 individuals with seasonal allergic asthma, as well as 16 healthy controls. All participants were nonsmokers. Cytokines were frequently correlated with one another; for example, type-2 cytokine IL-5 was associated with type-2 IL-4-inducible CCL-26 (nasal r=0.73; P <.0001; bronchial r=0.77; P <.0001). CCL-26 was also moderately correlated with IL-13 (r=0.57; P <.0001). IL-10, a regulatory cytokine, shows an association with levels of TNF-alpha expression in lower and upper airways (r=0.38; P =.024) and between organs (lower airway r=0.61; P <.0001; upper airway r=0.61; P <.0001).
Nasal expression of IL-10 showed an association with perceived stress burden (r=0.42; P =.01), while perceived stress burden was strongly associated with asthma control score (r=0.78; P =.003). IL-24 was of particular interest due to its moderate relation between lower and upper airways (r=0.53; P =.001). The asthma control score was negatively associated with nasal IL-24 (r= –0.85; P =.001).
The participants’ sputum supernatants were analyzed along with nasal secretions using multiarray technology. The rhinoconjunctivitis questionnaire on life quality, perceived stress questionnaire, and asthma control score were used to gather clinical scores. Analysis also included additional sputum flow cytometry and standard sputum differential cell counts. A 2-sided Spearman’s rank correlation was used to assess the relationship between possible proxy biomarkers, which researchers examined through the biomarker signal of both lower and upper airways. The selection was enhanced through the inclusion of known pathomechanisms.
The researchers concluded, “Comprehensive analysis of biomarkers in upper and lower airways revealed greatest relation to lower airway biomarker specifically IL-24. All other biomarker candidates showed weak to moderate correlation between upper and lower airways (r<0.5).”
Disclosures: This study was supported by the German Center for lung research (DZL). Please refer to the citation link for a complete list of authors’ disclosures.
Zissler UM, Ulrich M, Jakwerth CA, et al. Biomatrix for upper and lower airway biomarker in allergic asthma [published online August 16, 2018]. J Allergy Clin Immunol. doi:10.1016/j.jaci.2018.07.027