Association between lone star tick bites and increased alpha-gal sensitization: evidence from a prospective cohort of outdoor workers

Background: Alpha-gal is an oligosaccharide implicated in delayed anaphylaxis following red meat consumption. Exposure to tick bites has been correlated with development of an allergic response to alpha-gal. However, evidence prospectively linking exposure to a single tick species and an immune response to alpha-gal is lacking. Methods: We used serum samples from a prior study cohort of outdoor workers in North Carolina, USA, with high exposure to the lone star tick,Amblyomma americanum, to prospectively evaluate the relationship between tick bites and anti-alpha-gal IgE antibodies. Results: Individuals who reported exposure to one or more tick bites were significantly more likely to have a positive change in anti-alpha-gal IgE compared to individuals with no reported tick bites. This relationship was not dependent on time. A trend toward increasing number of tick bites and increased anti-alpha-gal IgE levels was observed but not statistically significant. Conclusion: To our knowledge, this is the first study to prospectively link documented exposure toA. americanumbites and increased sensitization to alpha-gal in a cohort of outdoor workers. Our results support the role ofA. americanumas likely agents for eliciting an allergic response to red meat, and highlight the importance of preventing tick bites.