Preventive actions of allergen immunotherapy: the facts and the effects in search of evidence

Abstract

Allergen immunotherapy (AIT) is the only treatment that works on the causes of allergy. Available AIT nowadays are subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) for allergic rhinitis and asthma, while for allergy to Hymenoptera venom only subcutaneous route is recommended. A bulk of trials and meta-analyses demonstrated that efficacy and safety of AIT in decreasing allergic clinical symptoms and use of rescue medications, while its preventive capacity is yet under investigation. The most important of these effects is the prevention of potentially fatal anaphylactic reactions to Hymenoptera stings by venom immunotherapy (VIT). A certain number of studies thus far available showed that AIT, in both forms, is able to prevent the progress of allergic rhinitis into asthma and the development of new sensitizations. These effects should be related to the mechanisms of action of AIT. In fact, it has been demonstrated that both SCIT and SLIT are able to modify the allergen presentation by dendritic cells, with result in modification of the phenotype of allergen-specific T cells, switching from the typical of allergic inflammation Th2-type response to a Th1-type one. Also allergen-specific T regulatory (Treg) cells play a pivotal role by producing suppressive cytokines, such as IL-10 and TGF-beta. However, the only plain evidence of a preventive effect concerns VIT, while the other outcomes need to be furtherly investigated.

Safety of specific immunotherapy using an ultra-rush induction regimen in bee and wasp allergy

“…11,12,13 Most of them confirmed a large profile of the safety of rapid protocols, especially when the initial therapy lasted a maximum of 48 hours. 5,13 Data have also shown that the ultrarush protocol is the safest, 14,15 and our results confirm this finding. More adverse reactions have been observed in patients with an allergy to bee venom.…”

“…The protection with VIT achieved up to a 90-95% level of success. 1,5 The VIT to wasp or bee venom were used different allergen products due to completely different antigen sequences of this venom and the absence of significant cross reactivity and cross allergy between the wasp and bee venoms. 1 The adverse reactions during VIT were observed as local or systemic reactions.…”

“…In general, the safety has been confirmed, but in approximately one-third of patients, systemic reactions (mainly mild or moderate) during the initial phase of treatment have been observed. 1,5,6 To improve tolerability and to minimize the occurrence of serious side-effects, different dosing regimens (conventional, rush, cluster and ultra-rush), which operate on a variety of either continuous or intermittent schedules, have been proposed. 1,7 Presently, the ultra-rush VIT regiment is often used.…”

Real‐world benefits of allergen immunotherapy for birch pollen‐associated allergic rhinitis and asthma

“…Moreover, both ARC symptoms and symptomatic medication use were significantly reduced, by 22%‐30% ( P < 0.005 for all 5 years) and 27% vs placebo ( P < 0.001), respectively . Similarly, the Preventive Allergy Treatment (PAT) study showed that a 3‐year course of SCIT with standardized allergen extracts (birch and grass pollen) in children resulted in long‐term clinical effects, with a significantly lower asthma incidence among SCIT‐treated patients (relative to symptomatic medication alone) observed at 7 years after treatment cessation . Finally, the prior analyses of the LRx database provide real‐world evidence of the long‐term benefits of grass pollen SLIT in patients with AR with or without associated asthma in terms of slower progression of AR and AA medication intake, and reduced risk of new‐onset asthma medication use …”

Childhood atopic dermatitis: current developments, treatment approaches, and future expectations

“…There are many studies on immunotherapy and AD; however, outcomes of the reports are conflicting, and contrary to studies on allergic rhinitis, efficacy is questionable in AD [169]. Atopic march, a severe problem in children with AD, should be prevented; however, the preventive role of allergen immunotherapy has not been demonstrated yet [170]. Nevertheless, patients with severe AD and accompanying allergic rhinitis and/or asthma may be considered for allergen immunotherapy [171].…”