IGHE and allergic disease: In conclusion, we found that—among subjects from a vaccine cohort who were not selected due to history of MMA, allergic disease, or tick exposure –alpha-gal IgG levels were higher among subjects who were alpha-gal IgE-sensitized and subjects who were blood type A or O. Alpha-gal IgG levels constituted less than 0.1% of the total IgG repertoire and, among those who were IgE-sensitized, were not helpful for distinguishing subjects with or without MMA.