MicroRNAs as current diagnostic biomarkers and potential therapeutic targets in allergic and non-allergic rhinitis – A functional characterization

PURPOSE OF REVIEW: Allergic rhinitis affects up to one-quarter of the population in industrialized countries. This chronic inflammatory disease of the nasal mucosa is triggered by allergen exposure and mediated by immunoglobulin E, leading to immune dysregulation. Diagnosis typically relies upon skin prick tests, serum-specific immunoglobulin E levels and nasal allergen provocations. Differentiation from non-allergic rhinitis remains a diagnostic challenge. Recent research has identified novel microRNAs, small non-coding RNA regulating post-transcriptional gene expression, as key regulators of immunological pathways with great potential as disease-specific targets in diagnostics and therapy. The purpose of this review is to explore novel therapeutic and diagnostic possibilities regarding novel miRNAs. RECENT FINDINGS: This functional review evaluated current evidence specific to miRNA expression in allergic and non-allergic rhinitis. Seven microRNAs (miR-29a, miR-135a, miR-143, miR-146a, miR-150-5p, miR-223, miR-451) are discussed as potential diagnostic markers and therapeutic agents in the future. Interventional studies, including human and animal studies, are reviewed. The available evidence suggested that selected microRNAs may show specificity and sensitivity as biomarkers for allergic and non-allergic rhinitis in future human trials. Therapeutic options involving miRNAs have shown great promise but still lack validation in clinical studies. In this review, we have identified several challenges in microRNA-based diagnostic approaches and suggested strategies to facilitate future development. MiRNA research in AR has revealed their role as both diagnostic biomarkers and therapeutic agents in several different mechanisms that are currently under investigation. Dysregulation of miRNA expression has been documented in asthma and allergic rhinitis, but data regarding non-allergic rhinitis remain limited.