A novel detection method for cross-linking of IgE-receptors by autoantibodies in chronic spontaneous urticaria

Background: Autoantibodies (AAbs) against immunoglobulin E (IgE) antibodies (Abs) and their highaffinity receptor alpha subunits (Fc epsilon RI alpha) are key factors in the elicitation of type IIb autoimmune chronic spontaneous urticaria (type IIb aiCSU). In this study, we aimed to develop a new method to detect functional anti-Fc epsilon RI alpha and anti-IgE AAbs, which can crosslink the plural FceR.a molecules and IgE Abs on the surface of mast cells and basophils, in sera from aiCSU patients using the amplified luminescence proximity homogeneous assay (Alpha).Methods: Sera were obtained from 14 aiCSU patients, as diagnosed by recurrent chronic spontaneous urticaria episodes and positive results for the autologous serum skin test and/or histamine release test (HRT). The AAbs to Fc epsilon RI alpha and IgE Abs were determined in sera from aiCSU patients using enzyme-linked immunosorbent assay (ELISA) and Alpha by cross-linking (AlphaCL) of IgE Abs and/or FceR.a.Results: Serum anti-Fc epsilon RI alpha and anti-IgE AAb levels were not significantly different between aiCSU patients and healthy subjects in ELISA. Anti-Fc epsilon RI alpha AAbs were detected in 10 of 14 aiCSU patients who displayed positive (5/5) and negative (5/9) results in the HRT for anti-Fc epsilon RI alpha AAbs by AlphaCL, whereas no signals were observed in healthy subjects. Additionally, anti-IgE AAbs were detected in two of four aiCSU patients who displayed positive results in the HRT for anti-IgE AAbs.Conclusions: A new assay method using AlphaCL can detect anti-Fc epsilon RI alpha and anti-IgE AAbs with Fc epsilon RI alpha and IgE-crosslinking abilities in sera from aiCSU patients. This simple and practical assay method may be available as a diagnostic tool for urticaria patients. Copyright (c) 2021, Japanese Society of Allergology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

背景：针对免疫球蛋白E（IgE）抗体（Abs）及其高亲和力受体α亚单位（FcεRIα）的自身抗体（AAbs）是引发IIb型自身免疫性慢性自发性荨麻疹（IIb型aiCSU）的关键因素。在本研究中，我们旨在开发一种新方法，利用放大发光近距离均相检测法（Alpha）检测自身免疫性慢性自发性荨麻疹患者血清中具有功能的抗FcεRIα和抗IgE自身抗体，这些自身抗体能够使肥大细胞和嗜碱性粒细胞表面的多个FcεRα分子和IgE抗体发生交联。 方法：从14例自身免疫性慢性自发性荨麻疹患者获取血清，这些患者经反复慢性自发性荨麻疹发作以及自体血清皮肤试验和/或组胺释放试验（HRT）阳性结果确诊。采用酶联免疫吸附测定（ELISA）以及通过IgE抗体和/或FcεRα交联（AlphaCL）的Alpha法测定自身免疫性慢性自发性荨麻疹患者血清中针对FcεRIα和IgE抗体的自身抗体。 结果：在ELISA中，自身免疫性慢性自发性荨麻疹患者和健康受试者之间血清抗FcεRIα和抗IgE自身抗体水平无显著差异。通过AlphaCL检测，14例自身免疫性慢性自发性荨麻疹患者中有10例检测到抗FcεRIα自身抗体，其中抗FcεRIα自身抗体的组胺释放试验结果为阳性（5/5）和阴性（5/9），而在健康受试者中未观察到信号。此外，在抗IgE自身抗体组胺释放试验结果为阳性的4例自身免疫性慢性自发性荨麻疹患者中有2例检测到抗IgE自身抗体。 结论：一种使用AlphaCL的新检测方法能够检测自身免疫性慢性自发性荨麻疹患者血清中具有FcεRIα和IgE交联能力的抗FcεRIα和抗IgE自身抗体。这种简单实用的检测方法可作为荨麻疹患者的一种诊断工具。版权所有（c）2021，日本变态反应学会。由爱思唯尔公司制作和托管。这是一篇在CC BY - NC - ND许可（http://creativecommons.org/licenses/by - nc - nd/4.0/）下的开放获取文章。