Artemisia annua sublingual immunotherapy for seasonal allergic rhinitis: a randomized controlled trial

Artemisia annua sublingual immunotherapy for seasonal allergic rhinitis: a randomized controlled trial:

Abstract

Background

Artemisia annua is an important autumnal pollen allergen for seasonal allergic rhinitis (SAR) in northern China. To date no study has investigated allergen immunotherapy with Artemisia annua. We aimed to investigate the efficacy and mechanisms underlying Artemisia annua‐sublingual immunotherapy (SLIT).

Methods

This was a randomized, double‐blind, placebo‐controlled phase III clinical trial involving 71 SAR patients; randomized to SLIT with Artemisia annua extract (n=47) or placebo (n=24) for 32 weeks. Total nasal symptom score (TNSS; primary clinical endpoint), was evaluated at baseline (peak pollen phase (PPP) in the previous year), initiation of Artemisia annua‐SLIT, 1^st PPP during SLIT, end of SLIT, and 2^nd PPP during follow‐up. Blood samples and nasal secretions were collected at beginning and after SLIT for assessment of T‐cells and inflammatory mediators. Safety was assessed according to adverse events (AEs) reported.

Results

Artemisia annua‐SLIT significantly reduced TNSS to a greater level from baseline (from 9.45±1.68 to 6.16±2.27) than placebo (from 9.29±2.09 to 9.05±2.40) at the 1^st PPP (P < 0.001), and sustained the improvement in symptoms throughout to the 2^nd PPP. Pre‐seasonal Artemisia annua‐SLIT for 16 weeks significantly decreased Th2 cells, increased nTreg and Tr1 cells in blood; and increased Cystatin 1(CST1) in nasal secretion after 16 and 32 weeks compared to pre‐treatment. Overall, 17/47 patients experienced mild local AEs, and 2 patients mild systemic AEs, after Artemisia annua‐SLIT.

Conclusion

Artemisia annua‐SLIT is an efficacious and safe treatment in patients with Artemisia annua SAR.