血清IgG4和IgG4/IgG比率在自身免疫性疾病鉴别诊断中的价值

Value of serum IgG4 and IgG4/IgG ratio in differential diagnosis of autoimmune diseases

目的:探讨血清免疫球蛋白G4(IgG4)和IgG4/免疫球蛋白G(IgG)比率在IgG4相关性疾病(IgG4-RD)和其他自身免疫性疾病鉴别诊断中的价值。方法:收集2021年1月至2022年7月在北京医院治疗的确诊为IgG4-RD患者35例、自身免疫性疾病患者937例及同期健康体检者200例的资料。使用IMMAGE 800和BNⅡ全自动特种蛋白分析仪检测IgG和IgG4,并绘制IgG4、IgG4/IgG比率的受试者工作特征曲线(ROC曲线)进行分析。结果:IgG4-RD组血清IgG4含量、IgG4/IgG比率分别为2.83(2.01,5.07)g/L、25(18,43)%,高于自身免疫性疾病患者组的0.35(0.16,0.72)g/L、3(1,6)%及健康对照组的0.27(0.14,0.49)g/L、2(1,4)%,差异均有统计学意义(U=795.50、82.50、1744.50、205.50,均P<0.001)。以IgG4≥1.35 g/L为标准,筛选出三组中IgG4≥1.35 g/L的病例,IgG4-RD组血清IgG4/IgG与非IgG4-RD患者组差异有统计学意义(U=453.50,P<0.001)。绘制IgG4、IgG4/IgG比率ROC曲线,IgG4为1.47 g/L时,敏感性91.7%,特异性83.5%,曲线下面积0.96;IgG4/IgG为12.5%时,敏感性91.4%,特异性85%,曲线下面积0.96。以IgG4≥1.47g/L、IgG4/IgG≥12.5%为诊断标准时,敏感性94.3%,特异性85.9%,曲线下面积0.96,高于单独血清IgG4诊断IgG4-RD综合敏感性的87.2%、特异性的82.6%。结论:由于非IgG4-RD疾病也可出现IgG4升高的现象,故以IgG4≥1.47 g/L为诊断标准时,其敏感性、特异性最高,同时联合检测IgG4/IgG比率可提高IgG4-RD的诊断效能。

Objective:To investigate the value of immunoglobulin G4(IgG4)and IgG4/immunoglobulin G(IgG)ratio in the differential diagnosis of IgG4-related diseases(IgG4-RD)and other autoimmune diseases.Methods:A total of 35 patients with IgG4-RD and 937 patients with autoimmune diseases who received treatment in Beijing Hospital from January 2021 to July 2022,and 200 subjects who concurrently underwent health checkups in the same hospital were included in this study.The IMMAGE 800 and BN II automatic special protein analyzers were used to detect IgG and IgG4.The receiver operating characteristic(ROC)curve of IgG4 and IgG4/IgG ratio was plotted.Results:Serum IgG4 level and IgG4/IgG ratio in the IgG4-RD group were 2.83(2.01,5.07)g/L and 25%(18%,43%)respectively,which were higher than 0.35(0.16,0.72)g/L,3%(1%,6%)in the autoimmune disease group and 0.27(0.14,0.49)g/L,2%(1%,4%)in the healthy control group(U=795.50,82.50,1744.50,205.50,all P<0.001).Taking IgG4≥1.35 g/L as the standard,patients with IgG4≥1.35 g/L in the three groups were screened out.There was a statistically significant difference in IgG4/IgG ratio between the IgG4-RD group and the non-IgG4-RD group(U=453.50,P<0.001).The ROC curve of IgG4 and IgG4/IgG ratio showed that when IgG4 was 1.47 g/L,the sensitivity was 91.7%,the specificity was 83.5%,and the area under the ROC curve was 0.96.When IgG4/IgG was 12.5%,the sensitivity was 91.4%,the specificity was 85%,and the area under the ROC curve was 0.96.Taking IgG4≥1.47 g/L and IgG4/IgG≥12.5%as the diagnostic criteria of IgG4-RD,the sensitivity was 94.3%,the specificity was 85.9%,and the area under the ROC curve was 0.96,which were higher than the sensitivity(87.2%)and diagnostic specificity(82.6%)provided by IgG4 alone.Conclusion:Because non-IgG4-RD diseases can also have the phenomenon of increased IgG4,when IgG4≥1.47 g/L is taken as the diagnostic criteria,its diagnostic sensitivity and specificity are the highest.Combined detection of IgG4 and IgG4/IgG ratio can increase the diagnostic efficacy of IgG4-RD.