title: Sustained effect of grass pollen subcutaneous immunotherapy on suppression of allergen-specific basophil response; a real-life, nonrandomized controlled study.
abstract: BACKGROUND
  An important advantage of allergen immunotherapy as compared to pharmacotherapy for allergic rhinitis is the long-term effect that persists after completing immunotherapy. The mechanism of the sustained effect of allergen immunotherapy is not completely understood.
  
  
  METHODS
  We conducted a 7-year study of monitoring allergen-specific basophil response and serological markers in 20 subjects with moderate-to-severe grass pollen-allergic rhinitis just before beginning and after up-dosing of subcutaneous grass pollen immunotherapy, before the first pollen season, and 1-2 years after completion of 3-5 years of treatment. Comparable untreated rhinitis subjects were followed at the same time points. Clinical outcomes included assessment of symptoms, use of rescue medication, and quality of life. The basophil response was also monitored after removal of IgG antibodies.
  
  
  RESULTS
  Basophil response assessed as area under the curve (AUC) halved during initiation of SCIT and was 55% lower 1-2 years after completing SCIT. In the untreated group, the basophil response remained comparable. Although immunotherapy-induced grass pollen-specific IgG4 levels decreased to near pre-immunotherapy levels after completing SCIT, the removal of IgG antibodies resulted in an increase in basophil response almost to the pre-immunotherapy levels. In untreated subjects, removal of IgG did not have any effect on basophil response.
  
  
  CONCLUSIONS
  Grass pollen immunotherapy induces sustained suppression of the allergen-specific basophil response that persists after completion of treatment and could account for long-term clinical tolerance. It also seems to be associated with persistent blocking activity of IgG antibodies.
authors: University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia.
authors: M
authors: M
authors: Zidarn
authors: M
authors: M
authors: Košnik
authors: M
authors: M
authors: Šilar
authors: N
authors: N
authors: Bajrović
authors: P
authors: P
authors: Korošec
mesh_terms: D000328:Adult; D001491:Basophils / Q000276:immunology*; D003888:Desensitization, Immunologic / Q000379:methods*; D005260:Female; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D006109:Poaceae / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology* / Q000517:prevention & control*; D013995:Time; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D007073:Immunoglobulin E
keywords: CD 63; allergen immunotherapy; basophil activation test; grass pollen allergy; sustained effect