肾组织M型磷脂酶A2受体和血清抗体在成人特发性膜性肾病的诊断价值

Detection and the clinical significance of M type phospholipase A2 receptor and autoantibodies a- gainst M type phospholipase A2 receptor in patients with idiopathic membranous nephropathy

目的探讨成人特发性膜性肾病（IMN）患者肾组织M型磷脂酶A2受体（PLA2R）、血清抗M型磷脂酶A2受体抗体（PLA2R-Abs）的表达及其与临床指标的关系。方法选取特发性膜性肾病（IMN）患者80例，继发性膜性肾病（SMN）28例[包括乙肝病毒相关性膜性肾病（HBV-MN）20例，狼疮性肾炎V型（LN-V）8例]，肾小球微小病变（MCD）21例，采用免疫组织化学染色法检测肾组织PLA2R，酶联免疫吸附法（ELISA）测定血清PLA2R-Abs浓度。结果（1）IMN患者肾组织PLA2R表达阳性率（72．5％）明显高于HBV-MN组（25％）、LN-V组（0）和MCD组（0）（P〈0．05），HBV-MN组PLA2R表达阳性率明显高于MCD组（P〈0．05）。（2）IMN患者血清PLA2R-Abs阳性率（83．8％）明显高于HBV-MN组（15％）、LN-V组（12．5％）及MCD组（0）（P〈0．05）；IMN组、HBV-MN组、LN-V组和MCD组血清PLA2R-Abs水平分别为81．29（91．3）RU／ml、6．25（13．2）RU／ml、6．93（11．3）RU／ml和3．08（4．7）RU／ml。（3）IMN患者中血清PLA2R-Abs阳性组患者血白蛋白水平[（23．85±4．99）g／L]明显低于阴性组[（32．76±6．38）g/L，P〈0．05]，24h尿蛋白水平[（5．02±2．16）g／d]明显高于阴性组[（3．24±2．68）g／d，P〈0．05]。血清PLA2R-Abs水平与尿蛋白及血清总胆固醇呈正相关，与血白蛋白呈负相关（P〈0．05）。结论肾组织PLA2R和血清PLA2R-Abs均是诊断IMN特异性生物学指标，血清PLA2R-Abs水平与IMN病情密切相关。

Objective To explore the role of M type phospholipase A2 receptor in glomeruli and serum M type phospholipase A2 receptor antibody in diagnosis and evaluation of idiopathic membranous nephropathy. Methods A total of 108 patients with biopsy-proved membranous glomerulonephritis （MN） was collected in this study as experimental group, including 80 patients with idiopathic membranous glomer- ulonephritis （IMN）, 20 patients with HBV-MN, and 8 cases with stage V lupus nephritis （LN-V）. Twenty one patients with biopsy-proved minimal change nephropathy （MCD） were used as control group. Phospho- lipase A2 receptor （PLA2R） in glomeruli was detected by immunohistochemical staining. Serum PLA2R antibodies （PLA2R-Abs） were measured by enzyme-linked immunosorbent assay. Results （1） Positive PLA2R glomerular deposits were found in 72. 5% IMN patients, while it was only 25%, 0, and 0 in pa- tients with HBV-MN, LN-V, and MCD. Compared to IMN group, PLA2R expression quantity was signifi- cantly lower in the other three groups （P 〈 0.05）. Compared to the HBV-MN group, PLA2R expression quantity was significantly lower in the MCD group （ P 〈 0. 05 ）. （2） Positive PLA2R-Abs were detected in 83.8% IMN patients, while it was only 15%, 12. 5%, and 0 in patients with HBV-MN, LN-V, and MCD. Compared to the IMN group, PLA2R expression quantity was significantly lower in the other three groups （P 〈 0. 05）. Concentration of PLA2R-Abs were 81.29 （91.3）RU/ml, 6. 25 （13.2）RU/ml, 6. 93 （11.3 ）RU/ ml, and 3.08 （4. 7） RU/ml in IMN, HBV-MN, LN-V, and MCD groups. （3） Concentration of serum albu- min was [ （23.85 ± 99）g/L] in PLA2R-Abs positive group, lower than that in the PLA2R-Abs negative group [ （32.76±6. 38）g/L]. Concentration of proteinuria was [ （5.02±2. 16）g/d] in PLA2R-Abs posi- tive group, higher than that in the PLA2R-Abs negative group [ （ 3.24 ~ 2. 68 ） g/d ], with a statistically significant difference （P 〈 0. 05 ）. Serum PLA2R-Abs levels were positively correlated with proteinuria and serum cholesterol levels, and negatively correlated with serum albumin levels （ P 〈 0.05 ）. Conclusions This experiment shows that the PLA2R and PLA2R-Abs both can be regarded as a specific marker for the diagnosis of IMN. Serum PLA2R-Abs was an important indicator to reflect the severity of IMN in patients.