Cao Thi Bich Tra, Cha Hyun Young, Yang Eun Mi, Ye Young Min
Department of Biomedical Science, Ajou University School of Medicine, Suwon, Korea.
Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
Allergy Asthma Immunol Res. 2021 May;13(3):498-506. doi: 10.4168/aair.2021.13.3.498.
Mas-related G-protein coupled receptor-X2 (MRGPRX2), a receptor on mast cells, basophils, and eosinophils associated with immunoglobulin E (IgE)-independent degranulation, has been reported to be highly expressed on cutaneous mast cells in patients with severe chronic spontaneous urticaria (CSU). We sought to investigate whether MRGPRX2 levels in the sera from CSU patients differ from those in healthy control subjects and to evaluate the clinical utility of MRGPRX2 levels in CSU patients. Severe CSU was defined as urticaria activity score over 7 days (UAS7) ≥ 28. Serum samples from 116 (73 severe and 43 non-severe) CSU patients and 50 healthy subjects were screened for MRGPRX2 using enzyme-linked immunosorbent assay. Serum MRGPRX2 levels were significantly higher in patients with severe CSU (median [interquartile range], 16.5 [10.8-24.8]) than in healthy controls (11.7 [6.5-21.2], = 0.036) and in non-severe CSU patients (8.7 [4.5-18.8], = 0.002), although they did not differ between healthy subjects and non-severe CSU patients. Serum MRGPRX2 levels in CSU patients showed positive correlations with UAS7 and specific IgE against in CSU subjects, whereas no correlations were observed for age, sex, urticaria duration, atopy, combined angioedema, autologous serum skin test positivity, or total IgE levels. Logistic regression analysis identified serum MRGPRX2 ≥ 12 ng/mL (odds ratio, 6.421; = 0.002) as an independent risk factor for severe CSU, along with increased serum total IgE levels, peripheral basophil percentage, and angioedema. In conclusion, we suggest that serum MRGPRX2 could help indicate severe CSU.
Mas相关G蛋白偶联受体X2（MRGPRX2）是一种存在于肥大细胞、嗜碱性粒细胞和嗜酸性粒细胞上的受体，与免疫球蛋白E（IgE）非依赖性脱颗粒有关，据报道在重度慢性自发性荨麻疹（CSU）患者的皮肤肥大细胞上高度表达。我们试图研究CSU患者血清中的MRGPRX2水平是否与健康对照者不同，并评估MRGPRX2水平在CSU患者中的临床应用价值。重度CSU定义为7天荨麻疹活动评分（UAS7）≥28。采用酶联免疫吸附测定法对116例（73例重度和43例非重度）CSU患者和50例健康受试者的血清样本进行MRGPRX2筛查。重度CSU患者的血清MRGPRX2水平（中位数[四分位间距]，16.5[10.8 - 24.8]）显著高于健康对照者（11.7[6.5 - 21.2]，P = 0.036）和非重度CSU患者（8.7[4.5 - 18.8]，P = 0.002），尽管健康受试者和非重度CSU患者之间无差异。CSU患者的血清MRGPRX2水平与CSU受试者的UAS7和针对[具体物质未提及]的特异性IgE呈正相关，而与年龄、性别、荨麻疹病程、特应性、合并血管性水肿、自体血清皮肤试验阳性或总IgE水平无相关性。逻辑回归分析确定血清MRGPRX2≥12 ng/mL（比值比，6.421；P = 0.002）是重度CSU的独立危险因素，同时还有血清总IgE水平升高、外周嗜碱性粒细胞百分比升高和血管性水肿。总之，我们认为血清MRGPRX2有助于指示重度CSU。
