Alpha-Gal Sensitization Dynamics in Individuals After Tick Bites With or Without Erythema Migrans

Area of Science:

• Immunology
• Epidemiology
• Tick-borne diseases

Background:

• α-Gal syndrome (AGS) is an emerging tick-borne illness linked to antibodies against the carbohydrate galactose-α-1,3-galactose (α-gal).
• AGS prevalence in the Dutch population, particularly concerning tick bites and erythema migrans (EM), remains unquantified.
• Understanding α-gal specific immunoglobulin E (sIgE) seroprevalence is crucial for diagnosing and managing AGS.

Purpose of the Study:

• To determine the α-gal sIgE seroprevalence in the Dutch population.
• To assess α-gal sIgE seroconversion following tick bites (TB).
• To investigate the relationship between EM and α-gal sIgE serum levels.

Main Methods:

• Cross-sectional study assessing α-gal sIgE in Dutch population controls, individuals with tick bites (TB), and erythema migrans (EM) cases.
• Longitudinal assessment of α-gal sIgE in TB and EM cases at baseline and 3 months post-event.
• Comparison of seroprevalence rates across groups using a cut-off of ≥ 0.10 kUA/L for α-gal sIgE.

Main Results:

• Baseline α-gal sIgE rates were 1.9% (controls), 10.3% (TB), and 19.1% (EM).
• After 3 months, rates rose to 17.9% for TB cases and remained elevated at 16.9% for EM cases.
• Both TB and EM groups exhibited significantly higher α-gal sensitization rates than the general population.

Conclusions:

• Tick bites are associated with increased α-gal sIgE sensitization in the Dutch population.
• EM cases show persistently elevated α-gal sIgE, suggesting a strong link between the condition and sensitization.
• The findings highlight the importance of considering AGS in individuals with a history of tick bites or EM.