Abstract

Allergic rhinitis (AR) is a common inflammatory disorder characterized by dysregulated immune responses. Exosomes, as extracellular vesicles carrying diverse functional RNAs, play essential roles in intercellular communication. However, the profiles and regulatory roles of circulating exosomal RNAs in AR remain largely unknown. This study aimed to characterize serum exosomal RNAs in AR patients and explore their potential association in immune regulation. Serum-derived exosomes from AR patients and healthy controls were analyzed using small RNA and long non-coding RNA sequencing. Four exosomal microRNAs—hsa-miR-186-5p, hsa-miR-184, hsa-miR-454-3p, and hsa-miR-4446-3p—were significantly downregulated in AR, and their differential expression was further validated by RT-qPCR. To explore their potential downstream effects, integrated analysis of public mRNA transcriptomic datasets and miRNA target prediction identified CADM1 as a putative target of hsa-miR-186-5p. Single-cell RNA sequencing analysis further revealed that CADM1 was highly expressed specifically in plasma cells from patients with seasonal allergic rhinitis. Functional enrichment analysis demonstrated that plasma cells with high CADM1 expression showed enrichment in immune-related signaling pathways, suggesting a possible link between the exosomal hsa-miR-186-5p– CADM1 axis and plasma cell function in AR. These findings suggest that the exosomal hsa-miR-186-5p– CADM1 axis may be associated with plasma cell-mediated immune responses in allergic rhinitis. Circulating exosomal microRNAs may serve as non-invasive biomarkers and provide a foundation for further investigation into allergic inflammation.