Sublingual immunotherapy increases Treg/Th17 ratio in allergic rhinitis

BACKGROUND: Few studies investigated the effects of sublingual immunotherapy (SLIT) on the peripheral regulatory T cells (Tregs)/Th17 ratio. OBJECTIVE: To investigate the effectiveness of SLIT in children with allergic rhinitis (AR) and the effects on the Tregs/Th17 ratio. METHODS: This was a retrospective study of children who were treated for AR between April 2017 and March 2018 at one hospital. The patients were grouped according to the treatments they received: SLIT + pharmacotherapy vs pharmacotherapy alone. RESULTS: Eighty children (51 boys and 29 girls; 40/group) were included. The visual analog scale (VAS) and medication scores at 1 year in the SLIT + pharmacotherapy group were 2.70 ± 1.08 and 1.1 ± 0.8, respectively, which were lower than at baseline (7.7 ± 1.2 and 3.6 ± 1.0, respectively) (both Ps < 0.05). For the pharmacotherapy group, the VAS score was decreased at 1 year vs baseline (3.3 ± 1.2 vs 7.4 ± 1.0; P < 0.05), but the medication score did not change (P > 0.05). In the SLIT + pharmacotherapy group, the Treg percentage increased, while the Th17 percentage decreased at 1 year (both Ps < 0.01). The percentages of Tregs and Th17s did not change in the pharmacotherapy group (both Ps > 0.05). CONCLUSIONS: SLIT + pharmacotherapy can increase the Treg percentage and decrease the Th17 percentage in the peripheral blood of children with AR.