engleski

House dust mite immunotherapy increased transforming growth factor-beta1-producing T cells in asthmatic children

Recent evidence suggests that regulatory T cells and immunosuppressive cytokines such as TGF-beta1 and IL-10 may have a role in clinically effective allergen-specific immunotherapy (SIT). Our objective was to study the frequency of regulatory T cells and expression of molecules associated with their functions (CTLA-4, TGF-beta1 and IL-10) in samples obtained from children allergic to house dust mite (HDM) during subcutaneous allergen SIT. In this uncontrolled open-label study, peripheral blood mononuclear cells were obtained from 16 children allergic to house dust mite before and at 3 and 12 months of SIT, and from 10 healthy children. The percentage of CD4+ regulatory T cells (CD69-CD45RO+CTLA-4+ and CD3+CD4+CD25+FOXP3+ markers) and production of IL-10 and TGF-beta1 were analyzed by flow cytometry. Clinical parameters such as symptom score, medication requirements, FEV1, PEFR, and serum IgE were also determined. All clinical parameters improved during immunotherapy. The percentage of CD4+CD25+CD69-CD45RO+ regulatory T cells remained unchanged. CTLA-4+ expressing regulatory T cells transiently increased after three months of immunotherapy, while the percentage of CD3+CD4+CD25+FOXP3+ cells did not change after one year of immunotherapy initiation. TGF-beta1 positive cells increased during immunotherapy and IL-10 positive cells transiently decreased after three months of immunotherapy. In conclusion, clinically effective subcutaneous HDM specific immunotherapy in children was accompanied by an increased number of TGF-beta1 positive T cells and transient increase in the proportion of CTLA-4+ regulatory T cells. The percentage of IL-10 positive T cells transiently decreased after three months of SIT, which is inconsistent with some previous studies conducted in adults. The results allow us to conclude that although regulatory T cells and immunosuppressive cytokines TGF-beta1 and IL-10 play a significant role in the mechanism of antigen-specific immunotherapy, they are poor marker of SIT efficacy.

children; asthma; allergy; immunotherapy; intracellular staining; flow cytometry

nije evidentirano