尿液IgG4检测在特发性膜性肾病诊断中的价值分析

Value analysis of urine IgG4 detection in the diagnosis of idiopathic membranous nephropathy

目的 探讨尿液免疫球蛋白-G(IgG)4检测在特发性膜性肾病(IMN)诊断中的价值。方法 选取2018年11月-2020年11月于我院肾病科行肾活检病理诊断为膜性肾病(MN)(75例)以及同期体检的健康人(健康组,30例),将MN患者分为特发性膜性肾病组(观察组,45人)和继发性膜性肾病组(对照组,30人),所有患者均进行血液尿液检查,记录实验室检查指标、不同病理分期的实验室指标、IgG4行ROC曲线分析结果。结果 三组间的尿IgG4水平对比差异有统计学意义,观察组的尿IgG4水平均高于对照组和健康组,观察组与对照组的ACR(尿微量白蛋白/肌酐)高于健康组,eGFR(肾小球滤过率)低于健康组(P<0.0167),三组间的尿素(BUN)、血肌酐(SCr)、尿酸(UA)、24小时尿蛋白的含量(24h UP)、IgG、补体C3、C4对比差异无统计学意义(P>0.05);Ⅰ期与Ⅱ~Ⅲ期患者的BUN、UA、24h UPE、尿IgG4、IgG、补体C3、C4、SCr水平对比差异无统计学意义(P>0.05),IMN患者在Ⅱ~Ⅲ期的ACR高于I期,eGFR低于I期(P<0.05),IgG4诊断IMN的Cut-off值为5962.52ng/L,AUC为0.911(置信区间为0.823~0.965)。结论 ACR、eGFR可辅助诊断IMN的病情严重程度,但不能鉴别IMN与SMN,尿液IgG4可作为无创性检测指标鉴别诊断IMN,但其对于IMN的病变程度需进一步评估。

Objective To investigate the value of urine immunoglobulin G(IgG)4 detection in the diagnosis of idiopathic membranous nephropathy(IMN).Methods A total of 75 healthy patients(healthy group, 30 cases)who were pathologically diagnosed with membranous nephropathy(MN)by renal biopsy in the department of nephrology of our hospital from November 2018 to November 2020 were selected.MN patients were divided into idiopathic membranous nephropathy group(observation group, 45 cases)and secondary membranous nephropathy group(control group, 30 cases).Blood and urine tests were performed on all patients, and laboratory indicators, laboratory indicators of different pathological stages, and ROC curve analysis results of IgG4 were recorded.Results The urine IgG4 level of the observation group was higher than that of the control group and the healthy group.The ACR(urinary microalbumin/creatinine)of the observation group and the control group was higher than that of the healthy group, and the eGFR(glomerular filtration rate)of the observation group and the control group was lower than that of the healthy group(P<0.0167).There were no significant differences in urea(BUN),serum creatinine(SCr),uric acid(UA),24-hour urinary protein content(24h UP),IgG,complement C3 and C4 among the three groups(P>0.05).There were no significant differences in BUN,UA,24h UPE,urine IgG4,IgG,complement C3,C4 and SCr levels between stage ⅰ and stage ⅱ~ⅲ patients(P>0.05).The ACR of IMN patients in stage ⅱ~ⅲ was higher than that in stage I,and the eGFR of IMN patients was lower than that in stage I(P<0.05).The CUT-OFF value of IgG4 diagnostic IMN was 5962.52ng/L,and the AUC was 0.911(confidence interval: 0.823~0.965).Conclusion ACR and eGFR can assist in the diagnosis of the severity of IMN,but can not distinguish IMN from SMN.Urine IgG4 can be used as a noninvasive indicator for the differential diagnosis of IMN,but the severity of IMN should be further evaluated.