血清抗PLA2R抗体水平对特发性膜性肾病的诊断及预后评估

Clinical significance of serum anti-PLA2R antibody level in diagnosis and prognosis evaluation of idiopathic membranous nephropathy

目的探讨血清抗磷脂酶A2受体(PLA2R)抗体对特发性膜性肾病(IMN)的诊断及预后评估的临床意义。方法将2017年5月至2019年2月于中国医科大学附属第一医院肾脏内科住院治疗,行肾活检术,并于术前或术后1周内应用ELISA方法(欧蒙试剂盒)检测血清抗PLA2R抗体的302例患者,分为IMN组、继发性膜性肾病(SMN)组及非膜性肾病(non-MN)组,比较组间血清抗PLA2R抗体水平差异,分析血清抗PLA2R抗体与各项化验指标间相关性,绘制ROC曲线并通过计算约登指数得出诊断IMN的血清抗PLA2R抗体最佳截断值,应用生存分析评估不同PLA2R水平IMN患者预后差异。结果 IMN组的血清抗PLA2R抗体明显高于SMN组及non-MN组(P<0.05);IMN组的血清抗PLA2R抗体与年龄、24 h尿蛋白、血肌酐、总胆固醇、低密度脂蛋白、纤维蛋白原呈正相关(r=0.221、0.304、0.175、0.217、0.210、0.174,P<0.05),与血清白蛋白呈负相关(r=-0.306,P<0.05),与血红蛋白、三酰甘油、免疫球蛋白无相关性,SMN组及non-MN组的血清抗PLA2R抗体与各项临床化验指标均无相关性;当血清抗PLA2R抗体截断值为2.3 RU/mL时,约登指数最高,为0.841。曲线下面积AUC为0.948(P<0.05);血清抗PLA2R抗体≤60 RU/mL的患者经治疗后缓解率显著高于血清抗PLA2R抗体>60 RU/mL的患者(P<0.05)。结论血清抗PLA2R抗体与IMN疾病活动程度相关,诊断IMN的血清抗PLA2R抗体最佳截断值为2.3 RU/mL,确诊IMN时血清抗PLA2R抗体≤60 RU/mL的患者经治疗后更易缓解。

Objective To evaluate the clinical significance of serum anti-phospholipase A2 receptor(PLA2 R) antibody in the diagnosis and prognosis evaluation of idiopathic membranous nephropathy(IMN). Methods From May 2017 to February 2019,302 patients who were hospitalized in the Department of Nephrology, the First Affiliated Hospital of China Medical University, and underwent renal biopsy were collected. The serum anti-PLA2 R antibody was detected by using the Anti-PLA2 R ELISA(IgG) Kit(Euroimmun) within 1 week before or after biopsy. The patients were divided into IMN group,secondary membranous nephropathy(SMN) group and non-membranous nephropathy(non-MN) group. The difference in serum anti-PLA2 R antibody level among groups was compared, and the correlation between serum anti-PLA2 R antibody and various laboratory indexes was analyzed. ROC curve was drawn and the optimal cut-off value of serum anti-pla2 r antibody for diagnosis of IMN was obtained by calculating the Yeoden index, and the in difference prognosis of IMN patients with different PLA2 R levels was evaluated by using survival analysis. Results Serum anti-PLA2 R antibody of IMN group was significantly higher than that of SMN group and non-MN group(P<0.05). Serum anti-PLA2 R antibody of IMN group was positively correlated with age, 24-hour urinary protein, serum creatinine, total cholesterol, low-density lipoprotein and fibrinogen(r=0.221, 0.304, 0.175, 0.217, 0.210, 0.174, P<0.05), and negatively correlated with serum albumin(r=-0.306,P<0.05), but not correlated with hemoglobin,triglyceride and immunoglobulin. There was no correlation between serum anti-PLA2 R antibody and other laboratory indexes in SMN group or in non-MN group. When the cut-off value of serum anti-PLA2 R antibody was 2.3 RU/mL, the Youden index was the highest at 0.841. The AUC under the curve was 0.948(P<0.05);patients with serum antiPLA2 R antibody ≤60 RU/mL had significantly higher remission rate after treatment than patients with serum anti-PLA2 R antibody>60 RU/mL(P<0.05). Conclusion Serum anti-PLA2 R antibody is correlated with the disease activity degree of IMN, the optimal cutoff value of serum anti-PLA2 R antibody for IMN is 2.3 RU/mL, and the patients with serum anti-PLA2 R antibody≤60 RU/mL in IMN diagnosis are more likely to be relieved after treatment.