Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, South Korea.
Division of Allergy, Immunology and Rheumatology, Taichung Veterans General Hospital, Taichung, Taiwan.
J Microbiol Immunol Infect. 2020 Feb;53(1):141-147. doi: 10.1016/j.jmii.2017.10.003. Epub 2017 Nov 14.
Chronic spontaneous urticaria (CSU) is a common skin disorder characterized by itchy wheals of at least 6 weeks in duration, wherein the autoimmune mechanism is involved to activate IgE receptors (FcεRIα) on mast cells. We aimed to assess levels of IgG autoantibody against FcεRIα in sera from CSU patients using dot-blot immunoassay.
We performed a hospital-based cross-sectional study of 125 CSU patients (64 ASST-positive, 61 ASST-negative) and 64 age-and sex-matched healthy controls. The cut-off value of IgG FcεRIα autoantibody was determined as the mean intensity plus two standard deviations of values in controls. Positivity for IgG autoantibody to FcεRIα was analyzed according to clinical parameters of disease duration, urticaria activity score (UAS), ASST, response to antihistamine treatment, complement levels, and the presence of other autoantibodies. Nonparametric tests were applied for statistical analyses.
IgG positivity to FcεRIα was noted in 24.8% of CSU patients and was significantly more frequent in ASST-positive patients than in ASST-negative patients (32.8% vs 16.4%, P = 0.040). Only 3.1% of healthy controls had this autoantibody. Complement 3 levels were significantly lower in anti-FcεRIα antibody-positive patients than antibody-negative patients (109.8 ± 19.9 vs 123.1 ± 30.9, P = 0.035). No significant associations were found between IgG positivity to FcεRIα and UAS, serum total IgE levels, atopic status, clinical responses to antihistamines, or the presence of anti-thyroid and anti-nuclear antibodies.
These findings suggest that circulating IgG autoantibody to FcεRIα in a subset of patients may be involved in the autoimmune mechanism of CSU. Further studies are needed to clarify its clinical significance.
慢性自发性荨麻疹（CSU）是一种常见的皮肤疾病，其特征为持续至少 6 周的瘙痒性风团，其中涉及自身免疫机制以激活肥大细胞上的 IgE 受体（FcεRIα）。我们旨在使用斑点印迹免疫分析法评估 CSU 患者血清中针对 FcεRIα 的 IgG 自身抗体水平。
我们进行了一项基于医院的横断面研究，纳入了 125 例 CSU 患者（64 例 ASST 阳性，61 例 ASST 阴性）和 64 名年龄和性别匹配的健康对照者。将 IgG FcεRIα 自身抗体的截断值定义为对照组值的平均强度加两个标准差。根据疾病持续时间、荨麻疹活动评分（UAS）、ASST、抗组胺治疗反应、补体水平和其他自身抗体的存在等临床参数分析 IgG 针对 FcεRIα 的自身抗体阳性情况。应用非参数检验进行统计学分析。
24.8%的 CSU 患者 IgG 针对 FcεRIα 呈阳性，且在 ASST 阳性患者中明显比 ASST 阴性患者更常见（32.8% vs 16.4%，P=0.040）。仅有 3.1%的健康对照者存在这种自身抗体。与 IgG 针对 FcεRIα 抗体阴性患者相比，抗体阳性患者的补体 3 水平显著降低（109.8±19.9 与 123.1±30.9，P=0.035）。IgG 针对 FcεRIα 的阳性与 UAS、血清总 IgE 水平、特应性状态、抗组胺治疗的临床反应或抗甲状腺和抗核抗体的存在之间均无显著相关性。
这些发现提示，在一部分患者中循环 IgG 针对 FcεRIα 的自身抗体可能参与了 CSU 的自身免疫机制。需要进一步研究来阐明其临床意义。
