Serum exosomal miR-146a-3p associates with disease severity and efficacy of sublingual immunotherapy in allergic rhinitis.

Background: Sublingual immunotherapy (SLIT) is an effective treatment for allergic rhinitis (AR), but its efficacy is variable among individuals. This study aimed to characterize serum exosome-derived microRNAs (miRNAs) and evaluate their abilities in predicting the efficacy of SLIT in AR.

Methods: RNA sequencing was performed to explore differentially expressed exosomal miRNAs in serum exosomes between AR patients and healthy controls (HCs). Sequencing analysis results were verified in an independent cohort, and the correlations between the levels of exosome-derived miRNAs and disease severity were evaluated. The most promising miRNAs were further tested in two AR cohorts treated with SLIT to assess their abilities in predicting short and long-term efficacy, respectively.

Results: The exosome-derived miRNAs profiling in the AR group was significantly different from the HC group, and differentially expressed genes were enriched and clustered in pathways such as PI3K-Akt and ErbB signalling pathways. The top three most significant miRNAs were verified by reverse transcription-polymerase chain reaction (qRT-PCR), and results showed that miR-146a-3p levels were significantly elevated in the AR group and correlated with the total and specific gE levels, the visual analogue scale of the total nasal symptom score (all p < 0.05). Further data in the first validation cohort suggested that miR-146a-3p levels were significantly downregulated in the effective group, and logistic regression showed that miR-146a-3p levels were associated with the short-term efficacy of SLIT(p < 0.05). The receiver operating characteristic (ROC) curve showed that miR-146a-3p could early predict SLIT efficacy (AUC = 0.669, p = 0.047). In the second validation cohort, miR-146a-3p levels were also decreased in the effective group and the ROC curve further confirmed its reliable accuracy in predicting the long-term efficacy of SLIT in AR patients (AUC = 0.749, p < 0.001).

Conclusion: Serum exosome-derived miRNAs may be involved in the development of AR and associated with its disease severity. Serum exosome-derived miR-146a-3p seems to be a novel biomarker for predicting the short and long-term efficacies of SLIT in AR patients.