Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznań, Poland.
Arch Immunol Ther Exp (Warsz). 2024 Jul 20;72(1). doi: 10.2478/aite-2024-0015. eCollection 2024 Jan 1.
Elevated immunoglobulin G4 (IgG4) serum antibodies are an important feature of IgG4-related disease. However, IgG4 antibodies can play a role in autoimmune thyroid disorders. In this study, we aimed to evaluate the impact of serum IgG4 levels on clinical features of Graves' disease (GD). We recruited 60 patients with GD (48 patients without thyroid eye disease, 12 patients with moderate-to-severe Graves' orbitopathy [GO], and 25 healthy control subjects). The prevalence of high IgG4 serum concentration was 4.2% among GD patients without GO and 33.33% in patients with moderate-to-severe GO. The group with GO had significantly higher median IgG4 levels (87.9 mg/dL) than the control group (41.2 mg/dL, = 0.034) and the GD without GO group (30.75 mg/dL, < 0.001). Patients with thyroid nodules had lower IgG4 levels than patients without thyroid nodules, but the difference was not statistically significant (35.7 [24.8; 41.53] mg/dL vs. 43 [30.1; 92.7] mg/dL, = 0.064). IgG4 as a diagnostic tool for moderate-to-severe GO had the following parameters: area under the curve (AUC): 0.851 ( < 0.001), at the cut-off value of 49 mg/dL, negative predictive value: 100%, positive predictive value: 48%, sensitivity: 100%, specificity: 73%. There were no significant differences between the high and normal IgG4 groups in thyroid hormones, antithyroid antibodies, and ultrasound features. Serum IgG4 levels are associated with some of the clinical features of GD and can help in the diagnostic process of the disease. More research is needed to better understand the pathophysiology of IgG4 involvement in GD.
血清 IgG4 水平与 Graves 病临床特征的关系
免疫球蛋白 G4（IgG4）升高是 IgG4 相关疾病的一个重要特征。然而，IgG4 抗体在自身免疫性甲状腺疾病中也有一定作用。本研究旨在评估血清 IgG4 水平对 Graves 病（GD）临床特征的影响。我们招募了 60 例 GD 患者（48 例无甲状腺眼病，12 例中重度 GD 性眼病[GO]，25 例健康对照）。无 GO 的 GD 患者中 IgG4 高浓度血症的患病率为 4.2%，中重度 GO 患者为 33.33%。GO 组 IgG4 中位数水平（87.9mg/dL）显著高于对照组（41.2mg/dL， = 0.034）和无 GO 的 GD 组（30.75mg/dL， < 0.001）。有甲状腺结节的患者 IgG4 水平低于无甲状腺结节的患者，但差异无统计学意义（35.7[24.8;41.53]mg/dL vs. 43[30.1;92.7]mg/dL， = 0.064）。IgG4 作为中重度 GO 的诊断工具，其曲线下面积（AUC）为 0.851（<0.001），截断值为 49mg/dL，阴性预测值为 100%，阳性预测值为 48%，灵敏度为 100%，特异性为 73%。在甲状腺激素、抗甲状腺抗体和超声特征方面，高 IgG4 组与正常 IgG4 组之间无显著差异。血清 IgG4 水平与 GD 的部分临床特征相关，有助于该疾病的诊断过程。需要进一步研究以更好地了解 IgG4 参与 GD 的病理生理学机制。
