Gene expression of cytokines IL-17 and IL-33 in plasma and nasal lavage fluid of patients with allergic rhinitis and bronchial asthma

The research presented in this article determined the systemic (blood plasma) and local (nasal lavage fluid) levels of interleukin-17 (IL-17) and interleukin-33 (IL-33) in healthy volunteers, patients with allergic rhinitis (AR), and patients with both allergic rhinitis and recently diagnosed bronchial asthma (AR+BA). IL-17 and IL-33 levels were consistent between AR and AR+BA patients but diverged when comparing either patient group or the combined group of all patients with healthy volunteers. These results indicate that AR and AR+BA patients represent a homogeneous group and suggest a role for IL-17 and/or IL-33 in the progression of AR to AR+BA. In conclusion, our data show that patients with AR only and those who progress to AR+BA from AR alone have elevated IL-17 levels in both nasal lavage fluid (NLF) and serum. This finding is consistent with recent studies and identifies a novel population of AR+BA patients with elevated IL-17 levels. The possibility of novel IL-33 regulatory mechanisms in these patients warrants further research.