Objectives: To assess the efficacy of venom immunotherapy (VIT) and monitor changes in in vivo and in vitro test results after 5 years oftreatment and subsequent follow-up. To study the profile of immunoglobulin (Ig) E to individual allergens prior to treatment and 1 year afterwards.

Methods: We studied 562 patients with hymenoptera venom allergy (438 to bee, 124 to wasp), all of whom underwent immunotherapy with Apis or Vespula extract. The patients were followed up using conventional in vivo and in vitro tests, and in 51 cases, specific IgE against the main hymenoptera allergens was measured before starting and after 1 year of treatment.

Results: Of the 387 patients who completed VIT, 130 sensitized to Apis and 68 to Vespula suffered spontaneous re-stings during treatment. Of these, 123 (94.6%) did not suffer any reaction and 64 (94.1%) suffered only a local reaction. Sixty-two patients sensitized to Apis and 14 sensitized to Vespula suffered spontaneous re-stings after stopping treatment. Only 3 patients suffered a systemic reaction (grade I Müller).
At the end of treatment, the results of skin tests and specific IgE to whole extract improved significantly. Reductions in IgE to the main allergens were observed after 1 year of treatment (median differences in Ves v 5, –238.0, P=.0425; and in Api m 1, –183.0, P=.0024).

Conclusion: The high rate of spontaneous re-stings shows that efficacy is maintained for years after completing treatment in a real-world setting. Determination of IgE to individual venom allergens may offer new perspectives in the diagnosis and follow-up of these patients.

Key words: Apis. Vespula. Hymenoptera venom allergy. Venom immunotherapy. Component-resolved diagnosis.