# Effects of sublingual immunotherapy for dust mite on Th 17 / Treg cells in children with asthma

## TL;DR

This study shows that sublingual immunotherapy for dust mites improves asthma symptoms in children by balancing immune cells.

## Contribution

The study demonstrates how SLIT affects Th17 and Treg cells to induce immune tolerance in pediatric asthma.

## Key findings

- SLIT reduced Th17 cell percentages and IL-6 and IL-17 levels in children with asthma.
- SLIT increased Treg cell percentages and IL-10 levels, improving lung function.
- Non-SLIT group showed improvements but with less effectiveness compared to the SLIT group.

## Abstract

observing the clinical effects of dust mite sublingual immunotherapy (SLIT) on children with asthma, changes of Th17 / Treg cells and related cytokines in order to investigate the possible pathological mechanism of immune tolerance induced by SLIT.

Sixty children with asthma allergic to dust mites were included, divided into SLIT group (n = 30) and non-SLIT group (n = 30). Clinical symptoms of asthma in each group had been scored before, 1 year and 2 years after treatment. Meanwhile we also evaluated the proportion of Th17 and CD4+CD25+ Treg cells in peripheral blood using flow cytometry. Besides, cell culture supernatant was collected to detect the changes of IL-6, IL-10 and IL-17 levels.

We found that in SLIT group, asthma symptom and drug use score, Th17 cell percentages, IL-6 and IL-17 levels have significantly decreased throughout the study period (p < 0.05), while FEV1%, Treg cell percentages and IL-10 level have prominently increased throughout the study period (p < 0.05). By contrast, in non-SLIT group, asthma symptom score, lung function, Th17 cell percentages, IL-6 and IL-17 levels have all significantly improved, but on the whole lower than SLIT group (p < 0.05). However, we have observed no statistical differences in drug use score, Treg cell percentages, IL-10 level for non-SLIT group throughout the study period.

SLIT of Dust mite drops could change T immune cell profiles whereas improve asthma symptoms. SLIT might reverse the functional imbalance of Th 17 / Treg cells and induce immune tolerance by upregulating Treg cell function and downregulating Th17 cell function.