Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic review and meta‐analysis

Abstract

Background The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost‐effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis. Methods We searched nine international biomedical databases for published, in‐progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost‐effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random‐effects meta‐analyses. Results We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD −0.53, 95% CI −0.63, −0.42), medication (SMD −0.37, 95% CI −0.49, −0.26), and combined symptom and medication (SMD −0.49, 95% CI −0.69, −0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post‐discontinuation of AIT, suggesting a benefit in relation to symptom scores. Conclusions AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.

EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis

“…The primary audience are clinical allergists (specialist and subspecialists); the document may also provide guidance to other healthcare professionals (e.g, physicians from other disciplines, nurses, and pharmacists working across a range of primary, secondary, and tertiary care settings) dealing with AR. The development of the Guideline has been informed by a formal systematic review (SR) and meta-analysis of AIT for AR, 14 with systematic review principles being used to identify additional evidence, where necessary.…”

“…This was then pursued through a formal SR of the evidence by independent methodologists as previously published 14,19 ; only double-blind RCTs were included in the effectiveness analyses. We continued to track evidence published after our SR cutoff date of October 31, 2015, and, where relevant, studies were considered by the Taskforce chairs.…”

“…14 These were used to Repeated allergen administration at regular intervals to modulate immune response in order to reduce symptoms and the need of medication for clinical allergies and to prevent the development of new allergies and asthma. This is also sometimes known as allergen-specific immunotherapy, desensitization, hyposensitization, or allergy vaccination.…”

“…Long-term treatment efficacy: clinical benefit to the patient for at least 1 y after cessation of the AIT course. 14 …”

Rush immunotherapy with multiple aeroallergens is safe in an adult population

“…Subcutaneous allergen immunotherapy (SCIT) is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy (1) . SCIT protocols are performed in two stages: build-up (up-dosing) phase which involves the administration of increasing doses of allergen extracts until the effective (or maintenance) dose is reached, and the maintenance phase.…”