Long-term IgG4 determinations in hymenoptera-sensitive treated patients.

Area of Science:

• Immunology
• Allergy and Clinical Immunology
• Pharmacology

Background:

• Honey bee and vespid venom immunotherapy are established treatments for Hymenoptera stings.
• Previous research has focused on the short-term effects of venom immunotherapy.
• The long-term immunological response to venom immunotherapy requires further investigation.

Purpose of the Study:

• To evaluate the long-term effects of venom immunotherapy on venom-specific IgG4 antibody levels.
• To determine if venom-specific IgG4 levels correlate with clinical protection over extended periods.
• To investigate potential differences in mechanisms of short-term versus long-term immunity.

Main Methods:

• Prospective study of 46 patients (ages 3-67) with Hymenoptera sensitivity.
• Intradermal skin testing with venom extracts at varying concentrations.
• Measurement of venom-specific IgE and IgG4 antibody levels over time (up to 6.5 years).

Main Results:

• All patients showed an increase in venom-specific IgG4 during the first year of immunotherapy, followed by a plateau.
• After three years of continuous immunotherapy, 30 patients exhibited a gradual decline in IgG4 levels.
• Six patients with very low IgG4 levels remained clinically protected after accidental stings.

Conclusions:

• Long-term immunity following venom immunotherapy may not be solely mediated by sustained high levels of venom-specific IgG4.
• The immunological mechanisms underlying long-term protection might differ from those responsible for short-term effects.
• Further research is needed to elucidate the precise mechanisms of sustained clinical protection.