Allergen immunotherapy: immunomodulatory treatment for allergic diseases

Abstract

Allergen immunotherapy is currently the only immune-modifying treatment for allergic disease. At the present time it is indicated for the treatment of allergic rhinitis, asthma and venom hypersensitivity. Efficacy appears to be dose dependent, and the immunological mechanisms responsible for the clinical efficacy of immunotherapy are still being elucidated. Immunological changes associated with immunotherapy include induction of T regulatory cells, increase in allergen-specific immunoglobulin G4, increase in interleukin-10 production and downregulation of the T helper 2 response. The disadvantages of allergen immunotherapy include risk of adverse events and patient time and inconvenience. Risks of immunotherapy range from large local reactions to mild systemic reactions, such as rhinitis. Fatalities from immunotherapy injections have been reported at a rate of approximately one fatality per 2.5 million injections. Conventional subcutaneous immunotherapy build-up schedules involve administration of a single-dose increase each visit and it may take several months before a patient achieves the therapeutic maintenance dose. Accelerated schedules, such as rush and cluster, will allow the patient to achieve the maintenance dose sooner but there may be a greater risk of a systemic reaction. The current focus of immunotherapy research is to develop safer and more effective vaccines. Another approach to enhancing immunotherapy safety is through an alternative delivery method. Sublingual immunotherapy is clearly safer than subcutaneous immunotherapy, but further investigation is needed to determine optimal dose and appropriate patient selection.

A single-centre retrospective study of systemic reactions to subcutaneous immunotherapy

“…Subcutaneous immunotherapy (SCIT) is the standard approach for treating patients with sensitizations to aeroallergens if medical therapy is ineffective or not preferred, 1 with a strong evidence base supporting its use. 1,2 Systemic reactions represent the major adverse effect of immunotherapy. Risk factors for systemic reactions include symptomatic asthma, injections from new vials, injections during symptomatic seasons, dosing errors, history of previous systemic reactions and the use of betablockers.…”

“…Risk factors for systemic reactions include symptomatic asthma, injections from new vials, injections during symptomatic seasons, dosing errors, history of previous systemic reactions and the use of betablockers. 2 These reactions can be severe, and in rare cases, fatal. 1 Multiple studies have tried to characterize the underlying risks and quantify the incidence of systemic reactions and deaths due to SCIT.…”

Expression of a Chimeric Allergen with High Rare Codons Content in Codon Bias-Adjusted Escherichia coli: Escherichia coli BL21 (DE3)-Codon Plus RIL as an Efficient Host

“…Recently chimeric allergens have been extensively used for specific immunotherapy in the patients who are sensitized to the several allergens [6,22].…”

Immunotherapy with a Recombinant Hybrid Molecule Alleviates Allergic Responses More Efficiently than an Allergenic Cocktail or Pollen Extract in a Model of <b><i>Chenopodium album</i></b> Allergy

“…SIT of C. album allergy is currently performed with allergen extracts and has poor efficacy and many side effects. There are key problems with the use of extracts for immunotherapy, including batch to batch variations, reduced immunogenicity of certain allergens, poor representation of allergens and the presence of nonallergenic materials [2,3,4]. In spite of a lot of scientific effort to improve the quality of allergen extracts, it has failed to overcome these fundamental problems.…”