Background:Postural orthostatic tachycardia syndrome (POTS) is a disorder of orthostatic intolerance that primarily affects women of childbearing age. The underlying pathophysiology of POTS is not fully understood, but it has been suggested that autoimmunity may play a role. The aim of this study was to compare concentrations of autoantibodies to cardiovascular G protein–coupled receptors between patients with POTS and healthy controls.Methods:Sera were collected from 116 patients with POTS (91% female; medium age, 29 years) and 81 healthy controls (84% female; medium age, 27 years) from Calgary, Canada, and Malmö, Sweden. Samples were evaluated for autoantibodies to 11 receptors (adrenergic, muscarinic, angiotensin II, and endothelin) using a commercially available enzyme-linked immunosorbent assay.Results:Autoantibody concentrations against all of the receptors tested were not significantly different between controls and patients with POTS. The majority of patients with POTS (98.3%) and all controls (100%) had α1 adrenergic receptor autoantibody concentrations above the seropositive threshold provided by the manufacturer (7 units/mL). The proportion of patients with POTS versus healthy controls who fell above the diagnostic thresholds was not different for any tested autoantibodies. Receiver operating characteristic curves showed a poor ability to discriminate between patients with POTS and controls.Conclusions:Patients with POTS and healthy controls do not differ in their enzyme-linked immunosorbent assay–derived autoantibody concentrations to cardiovascular G protein–coupled receptors. These findings suggest that these tests are not useful for establishing the role of autoimmunity in POTS.

中文翻译：

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使用标准方法检测体位性心动过速综合征中的 G 蛋白偶联受体自身抗体

背景：姿势性直立性心动过速综合征 (POTS) 是一种直立不耐受疾病，主要影响育龄妇女。POTS 的潜在病理生理学尚未完全了解，但有人认为自身免疫可能发挥作用。本研究的目的是比较 POTS 患者和健康对照之间针对心血管 G 蛋白偶联受体的自身抗体浓度。方法：从 116 名 POTS 患者（91% 女性；中年，29 岁）和 81 名健康人中收集血清来自加拿大卡尔加里和瑞典马尔默的对照组（84% 为女性；中等年龄，27 岁）。使用市售的酶联免疫吸附测定法评估样品针对 11 种受体（肾上腺素能受体、毒蕈碱受体、血管紧张素 II 和内皮素）的自身抗体。结果：针对所有测试受体的自身抗体浓度在对照组和 POTS 患者之间没有显着差异。大多数 POTS 患者 (98.3%) 和所有对照组 (100%) 的 α1 肾上腺素能受体自身抗体浓度高于制造商提供的血清反应阳性阈值（7 单位/mL）。对于任何测试的自身抗体，超过诊断阈值的 POTS 患者与健康对照者的比例没有差异。接受者操作特征曲线显示区分 POTS 患者和对照者的能力较差。结论：POTS 患者和健康对照者的酶联免疫吸附试验衍生的针对心血管 G 蛋白偶联受体的自身抗体浓度没有差异。