Department of Clinical Laboratory, Peking University People's Hospital, No.11 Xizhimen South Street, Beijing, 100044, China.
Department of Rheumatology and Immunology, Peking University People's Hospital, No.11 Xizhimen South Street, Beijing, 100044, China.
Clin Rheumatol. 2017 Dec;36(12):2769-2774. doi: 10.1007/s10067-017-3685-7. Epub 2017 May 24.
Patients with IgG4-related disease (IgG4-RD) often have elevated serum IgG4 levels. Here, we aimed to evaluate the diagnostic performances of elevated serum IgG4 concentration and IgG4/IgG ratio for IgG4-RD. We retrospectively analyzed 1381 patients subjected to serum IgG subclass testing to differentiate IgG4-RD from other diseases at Peking University People's Hospital from 2012 to 2016. This sample included 133 IgG4-RD patients and 1248 non-IgG4-RD patients. Serum IgG subclass concentrations were measured using Siemens reagents. The median values (25th-75th percentile) for serum IgG4 concentration and IgG4/IgG ratio, respectively, were 8640 (3970-17750) mg/L and 0.339 (0.229-0.517) in IgG4-RD patients and 450 (220-920) mg/L and 0.032 (0.014-0.061) in non-IgG4-RD patients (p < 0.001). For distinguishing IgG4-RD from non-IgG4-RD, the optimal cut-off values of IgG4 and IgG4/IgG were 2100 mg/L and 0.114, respectively. The corresponding area under the curve (AUC) values were 0.964 and 0.970, respectively. Comparison of the receiver operating characteristic curves revealed a significant difference between these AUC values (p = 0.002). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), respectively, were 94.7, 91.6, 54.5, and 99.4% for the IgG4 optimal cut-off value and 96.2, 92.1, 56.4, and 99.6% for the IgG4/IgG optimal cut-off value. Our results confirmed that elevated serum IgG4 concentration and IgG4/IgG ratio were of great value for IgG4-RD diagnosis.
患者 IgG4 相关疾病 (IgG4-RD) 常伴有血清 IgG4 水平升高。本研究旨在评估血清 IgG4 浓度和 IgG4/IgG 比值升高对 IgG4-RD 的诊断性能。我们回顾性分析了 2012 年至 2016 年在北京大学人民医院接受血清 IgG 亚类检测以区分 IgG4-RD 和其他疾病的 1381 例患者。该样本包括 133 例 IgG4-RD 患者和 1248 例非 IgG4-RD 患者。采用西门子试剂检测血清 IgG 亚类浓度。血清 IgG4 浓度和 IgG4/IgG 比值的中位数（25 至 75 百分位数）分别为 IgG4-RD 患者的 8640（3970-17750）mg/L 和 0.339（0.229-0.517），非 IgG4-RD 患者的 450（220-920）mg/L 和 0.032（0.014-0.061）（p<0.001）。为了区分 IgG4-RD 和非 IgG4-RD，IgG4 和 IgG4/IgG 的最佳截断值分别为 2100mg/L 和 0.114。相应的曲线下面积（AUC）值分别为 0.964 和 0.970。比较受试者工作特征曲线发现这些 AUC 值之间存在显著差异（p=0.002）。IgG4 最佳截断值的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）分别为 94.7%、91.6%、54.5%和 99.4%，IgG4/IgG 最佳截断值的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）分别为 96.2%、92.1%、56.4%和 99.6%。我们的结果证实，血清 IgG4 浓度和 IgG4/IgG 比值升高对 IgG4-RD 诊断具有重要价值。
