A double-blind randomized placebo-controlled trial with short-term beta-glucuronidase therapy in children with chronic rhinoconjunctivitis and/or asthma due to dust mite allergy.

BACKGROUND: Enzyme potentiated desensitization, in which beta-glucuronidase (BG) is administered with low doses of mixed allergens, was proposed in the 1970s for specific immunotherapy. The BG currently commercially available in a purified and standardized preparation devoid of any allergen has been suggested as a regulator in the allergic immune response, acting on the cytokine-network of type 2 helper T cells. A double-blind trial with a single-dose of BG proved effective in preventing symptoms in adult patients with rhinoconjunctivitis due to grass pollens. OBJECTIVE: The aim of this randomized double-blind placebo-controlled trial was to confirm the safety and effectiveness of double-dose intradermal BG immunotherapy in preventing symptoms in children suffering from chronic rhinoconjunctivitis and/or asthma due to dust mite. METHOD: We randomized 125 children with dust-mite related chronic rhinoconjunctivitis and/or asthma to the BG treated group (67) or the placebo group (58). All patients were screened before treatment (TO), at BG or placebo administration (T1 and T3), and at 3 and 9 months after T1 (T2 and T4). Drug intake and bronchial, nasal and ocular symptoms were recorded in a diary. RESULTS: Patients in both groups completed the study and BG treatment was well tolerated without side effects. Significant differences in symptoms were observed, in particular for conjunctivitis (P= .008). The total drug intake for allergic symptoms was significantly lower in the treated group than in the placebo group (P<. 01). CONCLUSIONS: BG immunotherapy is efficacious, safe, and well tolerated in allergic children. Moreover, good compliance with the administration of 2 doses per year and the lack of significant side effects makes the benefit/risk ratio of this treatment particularly favorable.

Analysis of circulating gammadelta T cells in children affected by IgE-associated and non-IgE-associated allergic atopic eczema/dermatitis syndrome.

Recent studies have suggested that not only alphabeta(+) T cells, but also the less common gammadelta(+) T cells may play a role as effectors and immunoregolatory cells in the development and perpetuation of allergic inflammation. The objective of this study was to focus on the role of gammadelta(+) T cells in atopic dermatitis (AD), a chronic relapsing inflammatory disease of the skin, often associated with allergic bronchial asthma. The present study employed flow cytometric analysis to compare numbers and phenotypic characteristics of gammadelta(+) T cells in the peripheral blood of children with atopic dermatitis and age-matched healthy controls. The percentage of circulating Vgamma 9Vdelta2(+) T lymphocytes was significantly increased in AD patients with respect to the age-matched controls, with a positive correlation with clinical score severity. The prevalent phenotype in both AD patients and controls was CD45RO(+), with no differences observed in the percentage of Vdelta2(+) CD45RO(+) between these groups. Conversely, memory CD45RO(+) CD62L(+) Vdelta2(+) lymphocytes were significantly lower in AD patients. Furthermore, naive circulating Vdelta2(+) T lymphocytes were significantly lower in AD children than in aged-matched controls. No correlation was observed between circulating Vgamma 9Vdelta2(+) expansion and IgE serum levels. It was concluded that an association exists between the levels of circulating gammadelta(+) T lymphocytes and atopic dermatitis, with a positive correlation with clinical score but no link with IgE serum levels. The pathophysiological role of gammadelta T lymphocytes in atopic dermatitis awaits further investigation.

A protocol for oral desensitization in children with IgE-mediated cow's milk allergy.

OBJECTIVES: To desensitize children with severe immunoglobulin (Ig)E-mediated cow's milk allergy in a period of 6 months by introducing increasing daily doses of cow's milk (CM) in order to enable the child to assume 200 ml of CM daily, or to induce tolerance of the highest possible CM dose. STUDY DESIGN: Twenty-one children at least 6 years old with severe IgE-mediated CM allergy were admitted to the study. A convincing history of IgE-mediated CM allergy or a positive double-blind placebo-controlled food challenge with CM confirmed the diagnosis. Oral desensitization was performed with increasing doses starting from 0.06 mg of CM proteins. RESULTS: Overall, 15 of 21 children (71.4%) achieved the daily intake of 200 ml during a 6-month period; three of 21 children (14.3%) tolerated 40-80 ml/day of undiluted CM; three of 21 children (14.3%) failed the desensitization because they presented allergic symptoms after ingesting minimal amounts of diluted CM. CONCLUSIONS: We successfully desensitized 15 of 21 children with severe IgE-mediated CM allergy in a period of 6 months. We stress the importance of the partial outcome in those three of 21 children who could not reach the maximum amount of 200 ml/day of whole CM, but were able to tolerate 40-80 ml/day of CM. In this way we dramatically reduced the risk of severe reactions after accidental or unnoticed introduction of low quantities of CM. We do not propose generalizing this method beyond trained staff.