Effect of Lactobacillus rhamnosus GG and vitamin D supplementation on the immunologic effectiveness of grass-specific sublingual immunotherapy in children with allergy.

BACKGROUND

An important issue in sublingual immunotherapy (SLIT) is how to improve efficacy.

OBJECTIVE

To compare the clinical and immunologic efficacy of SLIT given alone and, to enhance clinical efficacy, given with probiotic or vitamin D supplementation.

METHODS

One hundred children, ages 5-12 years, sensitive to grass pollen, with allergic rhinitis participated in a 5-month prospective, randomized, double-blind, placebo-controlled trial. Children received 5-grass SLIT 300 IR tablets with either vitamin D 1000 IU daily supplementation, probiotic, or placebo. The control group included children with allergy who did not qualify for immunotherapy. Primary end points included a symptom-medication score, lung function, and exhaled nitric oxide concentration. The secondary end point was the immunologic efficacy measured by the following: CD4(+)CD25(+)Foxp3(+) (forkhead box P3) cells, Toll-like receptor (TLR) 4, interleukin (IL) 1, IL-6, tumor necrosis factor, IL-10, and transforming growth factor β-1 levels in cell culture supernatants.

RESULTS

Reduction in the symptom-medication score and improvement in lung function as well as a significant increase in the percentage of CD4(+)CD25(+)Foxp3(+) in children who received SLIT in all the groups were observed compared with control group. In the SLIT-probiotic group, between-group analysis showed significantly higher CD4(+)CD25(+)Foxp3(+) induction compared with the SLIT group and higher reduction in the percentage of TLR-positive cell group compared with the SLIT-vitamin D group (Fig. 1). An increase in CD4(+)CD25(+)Foxp3(+) induction, reduction in TLR-positive cells recruitment and an increase in transforming growth factor β-1 production were independently associated with a better clinical effect of SLIT in children.

CONCLUSIONS

We demonstrated the clinical and immunologic effect of probiotic and vitamin D supplementation on SLIT. Probiotic supplementation showed better clinical and immunologic response in children with allergic rhinitis.