Artemisia annua-sublingual immunotherapy for seasonal allergic rhinitis: A randomized controlled trial.

Abstract

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 Aannua. We aimed to investigate the efficacy and mechanisms underlying Aannua-sublingual immunotherapy (SLIT). This was a randomized, double-blind, placebo-controlled phase III clinical trial involving 71 SAR patients, randomized to SLIT with Aannua extract (n=47) or placebo (n=24) for 32weeks. Total nasal symptom score (TNSS; primary clinical end point) was evaluated at baseline (peak pollen phase (PPP) in the previous year), initiation of Aannua-SLIT, 1st PPP during SLIT, end of SLIT and 2nd 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. 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 1st PPP (P<.001) and sustained the improvement in symptoms throughout to the 2nd PPP. Preseasonal Aannua-SLIT for 16weeks significantly decreased Th2 cells, increased nTreg and Tr1 cells in blood; and increased cystatin 1 (CST1) in nasal secretion after 16 and 32weeks compared with pretreatment. Overall, 17/47 patients experienced mild local AEs and 2 patients mild systemic AEs, after Aannua-SLIT. Artemisia annua-SLIT is an efficacious and safe treatment in patients with Aannua SAR.