title: Long-term clinical and immunological effects of allergen immunotherapy.
abstract: OBJECTIVE
  The present review updates current findings on long-term clinical and immunological outcomes after cessation of allergen immunotherapy for allergic respiratory disease.
  
  
  RESULTS
  Recent studies have shown that allergen immunotherapy has sustained disease-modifying effects that persist for years after discontinuation. This is in contrast to the effects of antiallergic drugs that do not induce tolerance to offending allergens. Long-term effects of immunotherapy include a reduction in nasal symptoms, a decrease in the use of rescue medication and improvement in quality of life. These benefits are accompanied by immunological changes such as the induction of allergen-specific IgG antibodies with inhibitory activity for IgE-facilitated binding of allergen-IgE complexes to B cells. One study reported a reduction in the development of asthma in children with seasonal pollen-induced rhinitis.
  
  
  CONCLUSIONS
  Allergen immunotherapy induces clinical and immunological tolerance as defined by persistence of clinical benefit and associated long-term immunological parameters after discontinuation of treatment. These findings are largely confined to studies of subcutaneous and sublingual immunotherapy for seasonal pollinosis. Further studies are needed to address potential long-term clinical effects for other seasonal and perennial inhaled allergens in both children and adults, and to identify potential biomarkers of tolerance.
authors: Section of Allergy and Clinical Immunology, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK. a.eifan@imperial.ac.uk
authors: Aarif O
authors: AO
authors: Eifan
authors: Mohamed H
authors: MH
authors: Shamji
authors: Stephen R
authors: SR
authors: Durham
mesh_terms: D000286:Administration, Sublingual; D000485:Allergens / Q000276:immunology* / Q000627:therapeutic use; D000818:Animals; D003888:Desensitization, Immunologic; D006801:Humans; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism; D007279:Injections, Subcutaneous; D012074:Remission Induction; D012130:Respiratory Hypersensitivity / Q000188:drug therapy* / Q000276:immunology* / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D028761:Withholding Treatment
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; D007073:Immunoglobulin E