血清抗磷脂酶A_2受体抗体滴度预测特发性膜性肾病的临床结局

Application of Serum anti-phospholipase A_2 receptor antibody titers in predicting clinical outcome of idiopathic membranous nephropathy

目的探讨血清抗磷脂酶A_2受体(PLA_2R)抗体滴度是否可以预测特发性膜性肾病的临床结局。方法收集肾活检证实为特发性膜性肾病的50例初发患者进行开放前瞻性研究,通过间接免疫荧光法测定患者血清抗PLA_2R抗体滴度,并随访至2016年6月。结果 39例(78%)患者血清抗PLA_2R抗体阳性。抗体阳性患者中,高滴度组患者入组时尿蛋白定量明显比低滴度组高(P<0.05);抗体滴度与初始尿蛋白定量之间呈正相关(r=0.558,P<0.001)。在仅支持治疗的前6个月,低滴度组患者自发缓解率明显比高滴度组高(57.1%vs9.1%,P<0.05)。在接受免疫抑制剂治疗后,低滴度组患者尿蛋白定量和血清白蛋白改善均比高滴度组快;治疗12个月末,低滴度组完全缓解率明显比高滴度组高(85.7%vs 21.4%,P<0.05)。远期随访,抗体低滴度组患者到达临床缓解的时间明显比高滴度组短(P=0.001);而高滴度组患者出现肾功能损害(血肌酐值持续大于133μmol/L)明显比低滴度组要早(P<0.05)。结论血清抗PLA_2R抗体滴度不仅能反映特发性膜性肾病患者免疫和疾病活动度,而且能预测患者治疗效果和临床结局。

Objective To apply the serum anti -phospholipase A2 receptor （PLAz R） antibody titers in predicting clinical outcome of idiopathic membranous nephropathy （IMN）. Methods An open prospective study of 50 biopsy - proven IMN patients in Guangzhou First People＇s Hospital between April 2012 and June 2014 were performed. Serum anti - PLA2R antibody titers were measured using an indirect immunofluoreseence assay. The patients were followed up until June 2016. Results Serum anti - PLA2R antibodies were positive in 39 （78%） patients. Among them, proteinuria was significantly higher in the high titers group than in the low titers group, and antibody titer was significantly correlated with baseline proteinuria （r = 0. 558, P 〈 0. 001 ）. In the first 6 months with supportive care, spontaneous remissions significantly occurred more frequently among low antibody titers patients （57.1% versus 9. 1% in the low and high titers group, P 〈 0. 05 ）. After immunosuppressive therapy, proteinuria and serum albumin levels were more rapidly improved in the low titers group. At the end of the 12th month of treatment, the probability of complete remission in the low titer group was significantly higher compared with that in the high titer group （85.7% versus 21.4% , P 〈 0. 05 ）. During the follow -up period, the time to proteinuria remission in the low titer group was significantly shorter than that in the high titer group （ P = 0. 001 ）. Patients in the high titer group significantly faster loss renal function （a serum creatinine level ≥ 133 μmol/L） than patients in the low titer group （ P 〈 0. 05 ）. Conclusion Serum anti - PLA： R antibody titer may not only serve as useful biomarkers for immunologic and disease activity of IMN patients, but also represent as a sensitive indicator of treatment efficacy and clinical outcome.