Division of Allergy & Clinical Immunology, University of Virginia, Charlottesville, Va.
United States International University, Nairobi, Kenya.
J Allergy Clin Immunol. 2021 Apr;147(4):1393-1401.e7. doi: 10.1016/j.jaci.2020.12.650. Epub 2021 Feb 1.
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.
α-半乳糖（α-Gal）特异性 IgE 是哺乳动物肉类过敏的一个原因，并且与北美的蜱虫叮咬、澳大利亚和欧亚大陆有关。来自发展中国家的报告表明，α-Gal 致敏很普遍，但研究甚少。
我们试图寻找厄瓜多尔和肯尼亚欠发达地区儿童中 α-Gal 致敏和未报告肉类过敏的原因。
评估了厄瓜多尔（n=599）和肯尼亚（n=254）儿童的 α-Gal 特异性 IgE 和总 IgE，并与美国东南部已知（n=42）和未知（n=63）哺乳动物肉类过敏的儿童进行了比较。厄瓜多尔儿童的饮食、潜在危险因素和寄生虫感染信息可用。评估了一组儿童的 α-Gal 特异性 IgG 和针对区域代表性寄生虫的抗体。
在厄瓜多尔（32%）和肯尼亚（54%），α-Gal 特异性 IgE 很普遍，但水平低于美国肉类过敏儿童。致敏与农村生活、感染 Ascaris 的抗体标志物和总 IgE 有关，但与 Ascaris 或 Trichuris 物种的活动性感染无关。在厄瓜多尔，87.5%的人至少每周食用一次牛肉，包括 83.9%的有 α-Gal 特异性 IgE 的人。厄瓜多尔的 α-Gal 特异性 IgG 水平不高，但高于美国儿童。
这些结果表明，在发展中国家寄生虫病流行地区，α-Gal 致敏是（1）常见的，（2）与 Ascaris 暴露有关，（3）与美国肉类过敏患者相比，特异性/总 IgE 的比例较低。
