title: Discontinuing venom immunotherapy: outcome after five years.
abstract: BACKGROUND
  The clinical and immunologic consequences of discontinuing venom immunotherapy are not well-defined. To determine which patients can safely stop treatment, we accepted all volunteers who had completed at least 5 years of maintenance venom immunotherapy regardless of the severity of the historical sting reaction, the persistence of venom skin test sensitivity, or any other variable.
  
  
  METHODS
  Sting challenge was performed every 1 to 2 years after therapy was stopped; and venom-specific skin tests were performed, and IgE antibody levels were measured.
  
  
  RESULTS
  Systemic symptoms occurred after challenge in eight of 270 stings (3%), in seven of 74 patients (10%); only two reactions were clinically significant. Venom skin test results became negative in 28% after 5 years of venom immunotherapy (at the time of discontinuation) and were negative in 56% to 67% of patients after 2 to 4 years without venom immunotherapy. There was a parallel decrease in the venom-specific IgE antibody levels. Challenge stings did not prevent the progressive decline in sensitivity, nor did they increase the risk of sting reaction even after two sequential stings 1 month apart.
  
  
  CONCLUSIONS
  Venom immunotherapy can be safely discontinued after 5 years of maintenance therapy in virtually all patients, with the possible exception of those in whom the level of venom sensitivity has not declined during therapy. Venom sensitivity decreases with time even after venom therapy is stopped. Insect stings do not cause re-sensitization, and there was no increased risk from sequential stings. There appears to be a late-onset, non-IgG-mediated mechanism for long-term suppression of allergic sensitivity by prolonged high-dose venom immunotherapy.
authors.affiliation: Johns Hopkins University, Asthma and Allergy Center, Baltimore, MD 21224-6821, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Golden
authors.forename: K A
authors.initials: KA
authors.lastname: Kwiterovich
authors.forename: A
authors.initials: A
authors.lastname: Kagey-Sobotka
authors.forename: M D
authors.initials: MD
authors.lastname: Valentine
authors.forename: L M
authors.initials: LM
authors.lastname: Lichtenstein
mesh_terms: D000707:Anaphylaxis / Q000517:prevention & control; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000097:blood / Q000276:immunology; D000918:Antibody Specificity; D001180:Arthropod Venoms / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D006927:Hymenoptera; D006967:Hypersensitivity / Q000175:diagnosis / Q000628:therapy*; D007073:Immunoglobulin E / Q000097:blood; D007167:Immunotherapy; D012882:Skin Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001180:Arthropod Venoms; C026408:anti-IgE antibodies; D007073:Immunoglobulin E