IgG autoantibodies against the alpha-chain of the high affinity IgE receptor are claimed to play a pathogenetic role in autoimmune urticaria. The best methods for detection of functional autoantibodies are currently the autologous serum skin test and the basophil histamine release assay. A simplified and feasible screening test would facilitate the diagnosis of autoimmune urticaria. Here we offer an explanation for the difficulties in establishing a screening test for autoantibodies directed against the alpha-chain of the high affinity IgE receptor in autoimmune urticaria. Identical autoantibodies in chronic urticaria patients and healthy donors belonging to the natural autoantibody repertoire were found by sequence analysis of anti-alpha-chain autoantibodies isolated by repertoire cloning from antibody libraries. These natural autoantibodies bound to the receptor and triggered histamine release but only if IgE was previously removed from the receptor. Diagnostic assays used for detection of antibodies directed against the IgE receptor may require signal comparison with and without the artificial removal of IgE, immune complexes, and complement in order to avoid false positive or negative results. After IgE removal diagnostic tests will detect natural autoantibodies against the high affinity IgE receptor regardless of whether they are pathogenic or not.

中文翻译：

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天然抗FcepsilonRIalpha自身抗体可能会干扰自身免疫性荨麻疹的诊断测试。

据称针对高亲和力IgE受体的α链的IgG自身抗体在自身免疫性荨麻疹中具有致病作用。目前检测功能性自身抗体的最佳方法是自体血清皮肤测试和嗜碱性粒细胞组胺释放测定。简化且可行的筛查测试将有助于自身免疫性荨麻疹的诊断。在这里，我们为在针对自身免疫性荨麻疹中针对高亲和力IgE受体的α链的自身抗体建立筛选测试中的困难提供了解释。慢性荨麻疹患者和属于天然自身抗体库的健康供体中的相同自身抗体是通过对从抗体库中克隆库中分离出的抗α链自身抗体进行序列分析而发现的。这些天然自身抗体与受体结合并触发组胺释放，但前提是事先已从受体中除去了IgE。用于检测针对IgE受体的抗体的诊断分析可能需要信号比较，无论是否人工去除IgE，免疫复合物和补体，以避免假阳性或阴性结果。去除IgE后，诊断测试将检测针对高亲和力IgE受体的天然自身抗体，无论它们是否具有致病性。并进行补充以避免错误的正面或负面结果。去除IgE后，诊断测试将检测针对高亲和力IgE受体的天然自身抗体，无论它们是否具有致病性。并进行补充以避免错误的正面或负面结果。去除IgE后，诊断测试将检测针对高亲和力IgE受体的天然自身抗体，无论它们是否具有致病性。