Changes in IL-10 and specific antibodies associated to successful Dermatophagoides pteronyssinus immunotherapy in children during the first year of treatment.

BACKGROUND Allergen-specific immunotherapy (SIT) is a long-term treatment of respiratory allergy. OBJECTIVE To look for early predictors of the effectiveness of Dermatophagoides pteronyssinus SIT. METHODS A prospective multi-centre study was carried out in Spain. Children with D. pteronyssinus rhinitis or asthma were invited to participate. The study was divided into times: T0 (recruitment); T1 (inclusion); T2 a-f (immunotherapy times) and T3 (the end of study). Efficacy of SIT was assessed by clinical scores, visual analogue scales (VAS) and lung function tests. We performed D. pteronyssinus skin tests at T1 and T3, and determined specific serum IgE, IgG4 and IL-10 at T1, T2f and T3. Data were analysed using Mann-Whitney and Kruskal-Wallis tests, compared using Wilcoxon and Chi-square tests, and correlated to Spearman test. All tests had a significance level of 0.05. RESULTS Thirty-eight children completed the study. At T1 all had rhinitis and 34 also had asthma. At T3, 30 patients had improved, six experienced no changes and two worsened. Improvement was associated to FEV1/FVC and VAS improvement; to a reduction in D. pteronyssinus skin prick test; to a progressive increase in serum levels of D. pteronyssinus IgE, and D. pteronyssinus, Der p1 and Der p2 IgG4. IL-10 levels showed an early increase at T2f (the end of initial build-up immunotherapy phase), and then a reduction at T3 (the end of a year of immunotherapy). Improvement associated to an early increase in IL-10 and was correlated with VAS and specific IgG4 evolution.