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

Cedar L Mitchell,Charles S Apperson,Meagan Vaughn,Scott P Commins,Steven R Meshnick,Feng-Chang Lin

doi:10.1186/s13071-020-04343-4

Cedar L Mitchell, Charles S Apperson + Show 4 more

Open Access

https://doi.org/10.1186/s13071-020-04343-4

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Abstract

BackgroundAlpha-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.MethodsWe 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.ResultsIndividuals 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.ConclusionTo our knowledge, this is the first study to prospectively link documented exposure to A. americanum bites and increased sensitization to alpha-gal in a cohort of outdoor workers. Our results support the role of A. americanum as likely agents for eliciting an allergic response to red meat, and highlight the importance of preventing tick bites.

Highlights

Alpha-gal is an oligosaccharide implicated in delayed anaphylaxis following red meat consumption
Alpha-gal syndrome (AGS) is characterized by a delayed onset allergic reaction following ingestion of mammalian meat or its derivatives, and a positive serum immunoglobulin E (IgE) result to alpha-gal (≥ 0.1 kU/l) [1, 2] Since 2009, AGS has been widely reported in North America, Australia, Europe and Asia, with bites from various tick
Secondary dose response analysis We investigated whether differences in anti-alpha-gal IgE levels were associated with the number of tick bites

Summary

Introduction

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. AGS is characterized by a delayed onset allergic reaction following ingestion of mammalian meat (e.g. beef, pork, lamb) or its derivatives, and a positive serum IgE result to alpha-gal (≥ 0.1 kU/l) [1, 2] Since 2009, AGS has been widely reported in North America, Australia, Europe and Asia, with bites from various tick. Mitchell et al Parasites Vectors (2020) 13:470 been retrospectively or circumstantially linked to the development of AGS [1, 3]; to date no study has evaluated changes in immune sensitization to alpha-gal following documented exposure to A. americanum bites. The purpose of this study was to prospectively define the relationship between A. americanum tick bites and anti-alpha-gal IgE antibody levels in a cohort of outdoor workers in the state of North Carolina, USA

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