Immunotherapy With Allergens

Abstract

Allergen immunotherapy has been shown to be efficacious in numerous studies for the clinical indications of allergic asthma and rhinitis, as well as hymenoptera venom hypersensitivity. How allergen immunotherapy improves clinical symptoms is still not entirely clear. Decreases in specific IgE follow a complex cascade of effects: a shifting of the cytokine milieu from T(H)2 to T(H)1 predominance, with resultant decrease in interleukin 4, decreased recruitment and activation of eosinophils, and decreased proliferation of mast cells. Allergen exposure has a lessened ability to stimulate an inflammatory cell response, with decreased target organ hyperreactivity. Since allergen immunotherapy is not without risk, the decision needs to be made whether injection therapy is safe and provides benefit not achievable by medical management. The continued clarification of optimal allergen concentrations through careful studies of standardized extracts will allow better control of adverse events by limiting unnecessarily potent mixtures.

Induction of T ‘regulatory’ cells by standardized house dust mite immunotherapy: an increase in CD4+CD25+ interleukin‐10+ T cells expressing peripheral tissue trafficking markers

“…With respect to dust mite‐sensitive persistent AR, the initial approach to management includes dust mite avoidance and standard pharmacotherapy such as antihistamines and intranasal steroids. In patients who have symptoms despite the above measures, allergen‐specific immunotherapy (SIT) is an adjunct to management, with efficacy documented in double‐blind controlled trials [4–8].…”

Sublingual immunotherapy: a double‐blind, placebo‐controlled trial with Parietaria judaica extract standardized in mass units in patients with rhinoconjunctivitis, asthma, or both

“…At present, specific immunotherapy is the only treatment known that can affect the natural course of respiratory allergic diseases by modifying the immune response ( 1). Conventional injective immunotherapy has been shown to be clinically effective if diagnosis, administration, and patient monitoring are carried out correctly ( 2), but its safety and patient compliance remain to be defined. Therefore, experimental and clinical efforts are underway both to improve allergen standardization and to explore new routes of immunotherapy administration ( 3).…”

The Role of Allergen Immunotherapy in Asthma Management

“…These variations included alum precipitation of the extract, the use of modi fied allergens (allergoids), oral IT, and a number of treatment schedule modifications to reduce the in terval between injections or the total number of in jections required. 11 Although there are claims that some of these modifications are therapeutically ad vantageous, none has emerged as widely favored over the traditional treatment regimen employing aque ous extracts administered at intervals of 1 to 4 weeks. Low-dose or "neutralizing-dose" therapies have been shown in controlled trials to be indistinguishable from placebo.…”

“…Dosing schedules vary appreciably and include "clustered" and "rush" protocols that sometimes make claims on improved safety or improved compliance and cost due to reduction of the number of injections required. 11 Accelerated or "rush" protocols appear to be commonly employed in Europe, whereas standard weekly injection schedules remain the most prevalent protocol in the United States. Similarly, in Europe each allergen is commonly given in a separate injection, whereas the norm for the United States is a mixture of treatment allergens.…”