Unmet Needs in Understanding Sublingual Immunotherapy to Grass Pollen

We have prepared this document, “Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update”, according to the evidence-based criteria, revising and updating chapters of the originally published paper, “Sublingual Immunotherapy: World Allergy Organization Position Paper 2009”, available at http://www.waojournal.org. Namely, these comprise: “Mechanisms of sublingual immunotherapy;” “Clinical efficacy of sublingual immunotherapy” – reporting all the data of all controlled trials published after 2009; “Safety of sublingual immunotherapy” – with the recently published Grading System for adverse reactions; “Impact of sublingual immunotherapy on the natural history of respiratory allergy” – with the relevant evidences published since 2009; “Efficacy of SLIT in children” – with detailed analysis of all the studies; “Definition of SLIT patient selection” – reporting the criteria for eligibility to sublingual immunotherapy; “The future of immunotherapy in the community care setting”; “Methodology of clinical trials according to the current scientific and regulatory standards”; and “Guideline development: from evidence-based medicine to patients' views” – including the evolution of the methods to make clinical recommendations. Additionally, we have added new chapters to cover a few emerging crucial topics: “Practical aspects of schedules and dosages and counseling for adherence” – which is crucial in clinical practice for all treatments; “Perspectives and new approaches” – including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, “Raising public awareness about sublingual immunotherapy”, as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Allergen-specific immunotherapy uses aqueous extracts of natural source materials as a basis for preparations to down regulate the allergic response. Recombinant DNA technology has enabled the cloning of many allergens, thus facilitating investigations aimed at improving efficacy and safety of immunotherapy. To determine the effectiveness of a mixture of 5 recombinant grass pollen allergens in reducing symptoms and need for symptomatic medication in patients allergic to grass pollen. A randomized, double-blind, placebo-controlled study of subcutaneous injection immunotherapy was performed in subjects with allergic rhinoconjunctivitis, with or without asthma. Primary endpoint was a symptom medication score compiled from separate symptom and medication scores. Secondary endpoints included a rhinitis quality of life questionnaire, conjunctival provocation, and specific antibody responses. The symptom medication score showed significant improvements in subjects receiving recombinant allergens as opposed to placebo, with reductions in both symptoms and medication usage. The rhinitis quality of life questionnaire revealed clinically relevant significant improvements in overall assessment and in 5 of 7 separate domains, and conjunctival provocation showed a clear trend in favor of active treatment. All treated subjects developed strong allergen-specific IgG(1) and IgG(4) antibody responses. Some patients were not sensitized to Ph l p 5 but nevertheless developed strong IgG antibody responses to that allergen. A recombinant allergen vaccine can be a effective and safe treatment to ameliorate symptoms of allergic rhinitis. The clinical benefit is associated with modification of the specific immune response with promotion of IgG(4) and reduction of IgE antibodies consistent with the induction of IL-10-producing regulatory T cells.