α-Gal specific-IgE prevalence and levels in Ecuador and Kenya: Relation to diet, parasites, and IgG 4

• Published in: Journal of allergy and clinical immunology Vol. 147; no. 4; p. 1393
• Main Authors: Wilson, Jeffrey M, Keshavarz, Behnam, James, Hayley R, Retterer, Maya K C, Schuyler, Alexander J, Knoedler, Alice, Workman, Lisa J, Ng'ang'a, Lucy, Chico, Martha E, Rönmark, Eva, Heymann, Peter W, Perzanowski, Matthew S, Platts-Mills, Thomas A E, Cooper, Philip J
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 01-04-2021
• Subjects: Adolescent; Adult; Age; Allergies; Animals; Ascaris; Ascaris - immunology; Ascaris - isolation & purification; Asthma; Child; Child, Preschool; Children; Diet; Disaccharides - immunology; Ecuador - epidemiology; Feces - parasitology; Female; Food allergies; Food Hypersensitivity - blood; Food Hypersensitivity - epidemiology; Food Hypersensitivity - immunology; Food Hypersensitivity - parasitology; Humans; Immunoglobulin E; Immunoglobulin E - blood; Immunoglobulin E - immunology; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin G - immunology; Kenya - epidemiology; Malaria; Male; Males; Meat; Parasitism; Prevalence; Red Meat; Risk factors; Rural areas; Sea level; Statistical analysis; Trichuris - isolation & purification; Virginia - epidemiology; Young Adult; Kenya; Ecuador; Virginia; United States > US; Europe; alpha-Gal; parasite; sensitization; mammalian meat allergy; IgE; Ascaris
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2020.12.650

IgE to α-Gal is a cause of mammalian meat allergy and has been linked to tick bites in North America, Australia, and Eurasia. Reports from the developing world indicate that α-Gal sensitization is prevalent but has been little investigated.
We sought evidence for the cause(s) of α-Gal sensitization and lack of reported meat allergy among children in less developed settings in Ecuador and Kenya.
IgE to α-Gal and total IgE were assessed in children from Ecuador (n = 599) and Kenya (n = 254) and compared with children with (n = 42) and without known (n = 63) mammalian meat allergy from the southeastern United States. Information on diet, potential risk factors, and helminth infections was available for children from Ecuador. IgG
to α-Gal and antibodies to regionally representative parasites were assessed in a subset of children.
In Ecuador (32%) and Kenya (54%), α-Gal specific IgE was prevalent, but levels were lower than in children with meat allergy from the United States. Sensitization was associated with rural living, antibody markers of Ascaris exposure, and total IgE, but not active infections with Ascaris or Trichuris species. In Ecuador, 87.5% reported consuming beef at least once per week, including 83.9% of those who had α-Gal specific IgE. Levels of α-Gal specific IgG
were not high in Ecuador, but were greater than in children from the United States.
These results suggest that in areas of the developing world with endemic parasitism, α-Gal sensitization is (1) common, (2) associated with Ascaris exposure, and (3) distinguished by a low percentage of specific/total IgE compared with individuals with meat allergy in the United States.