B cells in human food allergy have been studied predominantly in the blood. Little is known about IgE⁺ B cells or plasma cells in tissues exposed to dietary antigens. We characterized IgE⁺ clones in blood, stomach, duodenum, and esophagus of 19 peanut-allergic patients, using high-throughput DNA sequencing. IgE⁺ cells in allergic patients are enriched in stomach and duodenum, and have a plasma cell phenotype. Clonally related IgE⁺ and non-IgE–expressing cell frequencies in tissues suggest local isotype switching, including transitions between IgA and IgE isotypes. Highly similar antibody sequences specific for peanut allergen Ara h 2 are shared between patients, indicating that common immunoglobulin genetic rearrangements may contribute to pathogenesis. These data define the gastrointestinal tract as a reservoir of IgE⁺ B lineage cells in food allergy.

人类食物过敏中的 B 细胞主要在血液中进行研究。^{对暴露于膳食抗原的组织中的 IgE +} B 细胞或浆细胞知之甚少。我们使用高通量 DNA 测序对 19 名花生过敏患者的血液、胃、十二指肠和食道中的IgE ^{+克隆进行了表征。}过敏患者的IgE ⁺细胞在胃和十二指肠中富集，并具有浆细胞表型。克隆相关 IgE ⁺组织中不表达 IgE 的细胞频率表明局部同种型转换，包括 IgA 和 IgE 同种型之间的转换。花生过敏原 Arah 2 特异性的高度相似的抗体序列在患者之间共享，这表明常见的免疫球蛋白基因重排可能有助于发病机制。这些数据将胃肠道定义为食物过敏中 IgE ⁺ B 谱系细胞的储存库。