Discontinuing venom immunotherapy: outcome after five years

Area of Science:

• Allergy and Immunology
• Clinical Toxicology
• Immunotherapy Research

Background:

• Clinical outcomes of stopping venom immunotherapy (VIT) are unclear.
• Determining safe discontinuation criteria for VIT is essential.

Purpose of the Study:

• To assess the safety and immunological effects of discontinuing VIT after 5 years.
• To identify patient subgroups who may not be suitable for VIT cessation.

Main Methods:

• Volunteers completed at least 5 years of maintenance VIT.
• Post-discontinuation, patients underwent sting challenges, venom skin tests, and IgE antibody measurements every 1-2 years.

Main Results:

• Only 3% of sting challenges (10% of patients) resulted in systemic symptoms, with few clinically significant reactions.
• Venom skin test negativity increased from 28% at discontinuation to 56-67% after 2-4 years without VIT.
• Venom-specific IgE levels decreased, and challenge stings did not increase reaction risk or prevent sensitivity decline.

Conclusions:

• VIT can be safely discontinued after 5 years for most patients.
• Venom sensitivity decreases over time, even after therapy cessation.
• Prolonged VIT may induce a non-IgG-mediated mechanism for long-term allergy suppression.