老年膜性肾病患者抗M型磷脂酶A2受体抗体检测的临床意义

Clinical significance of detection for anti-M-type phospholipase A2 receptor antibody in elderly patients with membranous nephropathy

目的检测老年膜性肾病患者血清抗M型磷脂酶A2受体（PLAzR）抗体，并探讨其临床意义。方法应用蛋白免疫印迹法（Western blot）检测42例老年特发性膜性肾病（IMN）、45例非老年IMN、19例老年微小病变性肾病（MCN）、12例老年IgA肾病、8例老年乙肝相关性膜性肾病（HBV-MN）、8例老年局灶性节段性肾小球硬化（FSGS）患者的血清抗PLA2R抗体水平，并分析其与实验室指标的相关性。结果老年IMN与非老年IMN患者血清抗PLAzR抗体的阳性率分别为71．4％和73．3％，差异无统计学意义（P〉O．05）；老年IgA肾病、HBV-MN、MCN和FSGS患者的阳性率分别为16．7％、12．5％、5．3％和0％；老年和非老年IMN患者抗PLA2R抗体阳性率均显著高于老年继发性膜性肾病和老年其他肾小球肾炎患者（P〈O．01）。老年IMN患者的血清抗PLA2R抗体水平与尿蛋白量呈正相关，与血清白蛋白呈负相关（均P〈O．01）。结论抗PLAzR抗体是敏感性较高的IMN血清学标志物，该抗体有助于对老年和非老年特发性膜性肾病的诊断及对病情的监测。

Objective To detect serum level of anti-M-type phospholipase A2 receptor （PLA2R） antibody in elderly patients with idiopathic membranous nephropathy （IMN） and to explore its clinical significance in IMN disease. Methods A total of 134 patients with renal biopsy-proved glomerular diseases were enrolled in this study, including 42 elderly cases with IMN, 45 non-elderly cases with IMN, 19 elderly cases with minimal change nephropathy （MCN）, 12 elderly cases with IgA nephropathy （IgAN）, 8 elderly cases with hepatitis B-associated membranous nephropathy （HBV- MN） and 8 elderly cases with focal segmental glomerulosclerosis （FSGS）. Western blotting was used to detect serum anti-PLA2R antibody and the correlation of anti-PLA2R antibody with laboratory parameters in elderly IMN patients was analyzed. Results The elderly and non-elderly patients with IMN showed that the positive rate of anti-PLA2R antibody was 71.4% and 73.3%, respectively （P〉 0.05）. The positive rate of anti-PLA2R antibody in elderly IgA nephropathy, HBV-MN and MCN patients was 16.7%, 12.5% and 5.3% respectively. Anti-PLA2R antibody was not detected in serum from elderly FSGS patients. The positive rates of serum anti-PLA2R antibody were significantly higher in both elderly and non-elderly IMN patients than in elderly patients with secondary MN and other types of glomerlonephritis （ P 〈0.01） . Furthermore, anti-PLA2R autoantibody level was positively correlated with 24-hour urine protein level and negatively correlated with the concentration of serum albumin in elderly patients with IMN （P〈0.01）. Conclusions Anti-PLA2R antibody is a sensitive serological marker of IMN. Detection for anti-PLA2R antibody might be helpful for the diagnosis of both elderly and non-elderly IMN and for the monitor of IMN disease severity.