Certain Blood Types Linked to Protective Benefit for Red Meat Allergy

Those with blood type B or AB are an estimated 5-fold less likely to be diagnosed with red meat allergy.

Jonathan R. Brestoff, MD,



Although the recently recognized galactose-alpha-1, 3-galactose (alpha-gal) allergy, otherwise known as red meat allergy, has resulted in scares in the media, new data has revealed that those with blood type AB or B may be up to 5-fold less likely to be diagnosed with the condition.

Led by Jonathan R. Brestoff, MD, PhD, MPH, the team of investigators from the Washington University School of Medicine in St. Louis, Missouri, sought to determine if the similar molecular structure of alpha-gal to the B antigen would have any impact on the sensitivity to alpha-gal for those with the antigen in their blood.

“The molecular structure of alpha-gal is similar to that of the B antigen, a carbohydrate found on blood cells of people with B or AB blood types,” Brestoff said in a statement. “We hypothesized that people who express the B antigen have immune systems that are trained to ignore alpha-gal because it looks like an innocuous self-antigen. If that is correct, then people who make the B antigen should be less likely to undergo allergic sensitization to alpha-gal and, subsequently, protected from developing red meat allergy.”

The team took a cohort of 280 patients, 92 patients with red meat allergy and 188 controls, all with known A, B, and O blood types. They compared the expected and observed frequencies of blood type O, A, B, and AB, anticipating B or AB blood types to consist of an estimated 20.3% of the cohort with red meat allergy, however, the observed rate of B or AB blood types was only 4.35% (P = .005).

Brestoff and the team then utilized logistic regression to define the odds ratios (OR) of having red meat allergy according to blood type. They found that those with the B antigen in their blood were less likely to produce alpha-gal specific Immunoglobulin E (IgE) than their counterparts without it (OR, 0.19; 95% CI, 0.04—0.80; P = .023).

Additionally, those with AB or B blood types were also less likely to produce beef-specific IgE with an OR of 0.29 (95% CI, 0.11—0.80; P = .016).

Overall, patients without blood type B or AB were 5 times more likely to be diagnosed with the alpha-gal allergy (OR, 0.20; 95%CI, 0.07—0.62; P =.004). As a result, the authors concluded that those with red blood cells expressing the B antigen are protected from developing red meat allergy and are at lower risk to produce anti-alpha-gal IgE. An ABO blood type may impact an individual’s susceptibility to red meat allergy, they wrote.

“Patients expressing the B antigen were much less likely than those without the B antigen (blood types O or A) to react to alpha-gal,” Brestoff said. “In fact, patients with B or AB blood types were 5 times less likely to have been diagnosed with red meat allergy.”

The results of the study were presented at the 2018 American Academy of Allergy, Asthma, and Immunology/World Allergy Organization Joint Congress in Orlando, Florida.

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