Our study demonstrates that sublingual immunotherapy is effective in children and that it maintains the clinical efficacy for 4 to 5 years after discontinuation.

SummaryThe gastrointestinal system plays a central role in immune system homeostasis. It is the main route of contact with the external environment and is overloaded every day with external stimuli, sometimes dangerous as pathogens (bacteria, protozoa, fungi, viruses) or toxic substances, in other cases very useful as food or commensal flora. The crucial position of the gastrointestinal system is testified by the huge amount of immune cells that reside within it. Indeed, gut-associated lymphoid tissue (GALT) is the prominent part of mucosal-associated lymphoid tissue (MALT) and represents almost 70% of the entire immune system; moreover, about 80% of plasma cells [mainly immunoglobulin A (IgA)-bearing cells] reside in GALT. GALT interacts strictly with gastrointestinal functions in a dynamic manner; for instance, by increasing intestinal permeability in replay to particular stimulations, or orientating the immune response towards luminal content, allowing either tolerance or elimination/degradation of luminal antigens, or sometimes provoking damage to the intestinal mucosa, such as in coeliac disease or food allergy. The immune mechanisms implicated in these actions are very complex and belong to both innate and adaptive immunity; innate immunity supplies an immediate non-specific response that is indispensable before specific adaptive immunity, which needs 7-10 days to be efficacious, takes place. The results of their interactions depend upon different contexts in which contact with external agents occurs and may change according to different genetic settings of the hosts.

This study represents the first analysis of the safety of SLIT concerning the allergen dose employed in the treatment. There is evidence that AE occurrence is substantially not dose-dependent. This fact highlights two main clinical aspects: the elevated tolerability of SLIT in general and the safety of HAD regimen.

Our results suggest that this immunotherapy is effective for the treatment of asthma due to grass pollen in children.

Background:The minimum age to start specific immunotherapy with inhalant allergens in children has not been clearly established, and position papers discourage its use in children younger than 5 years.Objective: To assess the safety of high-dose sublingual-swallow immunotherapy (SLIT) in a group of children younger than 5 years.Methods: Sixty-five children (51 boys and 14 girls; age range, 38 -80 months; mean Ϯ SD age, 60 Ϯ 10 years; median age, 60 months) were included in this observational study. They were treated with SLIT with a build-up phase of 11 days, culminating in a top dose of 300 IR (index of reactivity) and a maintenance phase of 300 IR 3 times a week. The allergens used were house dust mites in 42 patients, grass pollen in 11 patients, olive pollen in 5 patients, Parietaria pollen in 4 patients, and cypress pollen in 3 patients. All adverse reactions and changes in the treatment schedule were compared in 2 subgroups: children 38 to 60 months old and children 61 to 80 months old.Results: The average cumulative dose of SLIT was 36,900 IR. Adverse reactions were observed in 11 children, none of them severe enough to require discontinuation of immunotherapy. Six reactions occurred in the 60 months or younger age group and 7 in the older than 60 months age group, with no differences between these 2 groups.Conclusion: High-dose immunotherapy in children younger than 5 years does not cause more adverse reactions than in children aged 5 to 7 years. There is no reason to forbear studies on safety and efficacy of these preparations in young children.Ann Allergy Asthma Immunol. 2005;95:254-258.