Lack of detectable alterations in immune responses during sublingual immunotherapy in children with seasonal allergic rhinoconjunctivitis to grass pollen.

BACKGROUND: Recent work indicates that subcutaneous specific immunotherapy induces specific T-cell anergy, a shift in the TH1/TH2 ratio, and antibody production in favor of IgG4. There are few data on sublingual immunotherapy (SLIT), especially in children. METHODS: We assessed the proliferation of peripheral blood mononuclear cells ((3)H-thymidine incorporation) and secretion of interleukin (IL)-4, interferon (IFN)gamma and IL-5 (ELISA) after in vitro stimulation with allergen or phytohemagglutinin (PHA) in 29 children with allergic rhinoconjunctivitis receiving SLIT with grass pollen before, and after 1 and 2 years of treatment in a multicenter placebo-controlled study on the efficacy of the treatment. Further, non-specific intracellular production of IL-4, IL-13, IFNgamma, IL-2, IL-10 and IL-5 (FACS) and serum total and specific IgE and IgG4 (ELISA) were analyzed. RESULTS: Proliferation and IL-4 and IL-5 secretion after stimulation with allergen or PHA did not differ between the groups. In addition, we observed no effect of SLIT on intracellular cytokine production. IFNgamma secretion after allergen coculture was comparable between the groups. Following PHA stimulation, IFNgamma secretion was significantly higher in the SLIT group after 1 year, and a trend was observable already before and after 2 years of treatment, probably due to the inhomogeneity in the groups despite randomization (for age and asthma). No significant changes were observed for sIgE/sIgG4 ratios over time either in or between the groups. CONCLUSION: During 2 years of SLIT in children with a positive effect on rescue medication use, we observed no significant effects on in vitro T-cell immune responses or immunoglobulins. So far, pediatric studies demonstrating stable effects of SLIT on such reactions are missing, probably due to limited effects of SLIT on systemic immunologic reactions.

A prospective, randomized, double-blind, placebo-controlled multi-centre study on the efficacy and safety of sublingual immunotherapy (SLIT) in children with seasonal allergic rhinoconjunctivitis to grass pollen.

BACKGROUND: Especially in childhood, sublingual immunotherapy (SLIT) could offer advantages over subcutaneous therapy. However, limited data on its efficacy is available. METHODS: In four German centres 97 children (age 3-14 years) with allergic rhinoconjunctivitis to grass pollen were enrolled in a prospective, double-blind trial comparing SLIT (Pangramin SLIT; ALK-SCHERAX, 0.5 microg major allergens, three times per week, 32 months) with placebo. Primary endpoint was a multiple symptom-medication score for changes in seasonal diary entries between the first and third year of the study (SLIT n=39; placebo n=38). RESULTS: The multiple symptom-medication score was significantly reduced by SLIT to 77.3% of the placebo group (P=0.0498). The subsequent analysis of the single endpoints did not reveal significant differences for symptom scores in favour of SLIT (85.1% of placebo group; P=0.22). However, the medication score improved significantly (67.1% of placebo group; P=0.0025). Furthermore, secondary endpoints assessing in vivo immune responses did not differ significantly between the groups. However, retrospective analysis showed some inhomogeneity for clinical and in vitro parameters at the beginning of the study. Allergic side effects with possible relation to the study drug were reported in both groups (SLIT 49%, placebo 27%, P=0.026). CONCLUSION: Our study indicates that SLIT had a positive effect on the reduction of a multiple symptom-medication score, mainly by significantly reducing rescue medication use, but had no significant effect on symptoms alone in children with rhinoconjunctivitis to grass pollen compared with a placebo.

The co-seasonal application of anti-IgE after preseasonal specific immunotherapy decreases ocular and nasal symptom scores and rescue medication use in grass pollen allergic children.

BACKGROUND: Specific immunotherapy (SIT) and treatment with anti-immunoglobulin (Ig)E antibody are complementary approaches to treat allergic rhinoconjunctivitis, which may be used for single or combined treatment. OBJECTIVE: A randomized, double-blind, placebo-controlled trial was conducted to compare the efficacy of single and combined treatment with SIT and anti-IgE (Omalizumab) in reducing symptom severity and rescue medication use. METHODS: A total of 221 subjects with birch and grass pollen allergic rhinoconjunctivitis aged 6-17 years were analysed during the grass pollen season. Group A (SITbirch + placebo) served as a reference group obtaining no effective treatment for grass pollen allergy. Group B received anti-IgE monotherapy during grass pollen season, group C SIT grass pollen monotherapy, and group D the combined treatment of SIT and Omalizumab. RESULTS: Preseasonal treatment with grass pollen SIT alone compared with SIT with the nonrelated allergen did not reduce symptoms or rescue medication use. Anti-IgE monotherapy significantly diminished rescue medication use and number of symptomatic days. The combined treatment with SIT and anti-IgE showed superior efficacy on symptom severity compared with anti-IgE alone. CONCLUSIONS: Co-seasonal Omalizumab therapy showed considerable effects in children with seasonal allergic rhinitis. The combination of SIT plus Omalizumab was clinically superior to each treatment alone during the first year of observation.