PLA2R和THSD7A在特发性膜性肾病中的临床应用评价

目的探讨肾小球M型磷脂酶A2受体(PLA2R)和1型血小板反应蛋白7A域(THSD7A)及两者血清抗体水平检测在膜性肾病中的临床应用评价。方法选取行肾活检确诊的原发性膜性肾病172例(IMN组)，另选取同期确诊的继发性膜性肾病7例(SMN组)。应用免疫荧光法检测肾组织PLA2R和THSD7A抗原表达，ELISA方法检测病人血清PLA2R和THSD7A抗体水平。结果IMN组中167例病人表现为单纯PLA2R阳性(97.1%)，SMN组中有3例PLA2R阳性(42.9%)，差异有统计学意义(P < 0.01)。IMN组中有5例THSD7A阳性(2.9%)，5例病人均合并PLA2R双阳(2.9%)，SMN组0例THSD7A阳性，差异无统计学意义(P>0.05)。IMN组中143例病人血清PLA2R抗体阳性(83.1%)，SMN组2例阳性(28.6%)，差异有统计学意义(P < 0.01)。2组病人血清中未检测出THSD7A抗体。2组病人性别、年龄、Alb、24hUpro、SCr、eGFR比较，差异均无统计学意义(P>0.05)。PLA2R-Ab与SCr、eGFR之间无相关关系(P>0.05)，与Alb之间存在明显负相关关系(P < 0.01)，与24hUpro之间存在正相关关系(P < 0.05)。PLA2R抗体阳性组Alb水平明显低于阴性组(P < 0.01)，PLA2R抗体阳性组24hUpro水平明显高于阴性组(P < 0.05)。结论PLA2R和THSD7A及其抗体检测有助于膜性肾病的诊断分型；PLA2R抗体水平可反映疾病活动度，可用于评估治疗效果；IMN病人THSD7A相关性膜性肾病的发病率较低。

Evaluation on clinical application of PLA2R and THSD7A in idiopathic membranous nephropathy

ObjectiveTo evaluate the clinical application of glomerular M-type phospholipase A2 receptor(PLA2R), thrombospondin type 1 domain-containing 7A(THSD7A) and their serum antibody levels in membranous nephropathy.MethodsA total of 172 cases of idiopathic membranous nephropathy(IMN) patients diagnosed by renal biopsy were selected as IMN group, and 7 cases of secondary membranous nephropathy(SMN) diagnosed in the same period were selected as SMN group.The expressions of PLA2R and THSD7A antigens in renal tissues were detected by immumofluorescence method, and the level of their serum PLA2R and THSD7A antibodies was measured by ELISA.ResultsA total of 167 cases in the IMN group showed positive for PLA2R alone(97.1%), and 3 cases in the SMN group were positive for PLA2R(42.9%), which showed statistically significant difference(P < 0.01).In the IMN group, 5 cases were positive for THSD7A(2.9%), and 5 cases showed positive for both PLA2R and THSD7A(2.9%); no THSD7A-positive case was detected in the SMN group, and the difference had no statistical significance(P>0.05).In the test of serum PLA2R, 143 cases in the IMN group showed positive result(83.1%), 2 cases in the SMN group were positive(28.6%), and the differences were statistically significant(P < 0.01).No THSD7A antibody was detected in the serum of the two groups.There were no statistically significant differences in sex, age, Alb, 24hUpro, SCr, and eGFR between the two groups(P>0.05).PLA2R-Ab had no correlation with SCr and eGFR(P>0.05), but had a significant negative correlation with Alb(P < 0.01), and a positive correlation with 24hUpro(P < 0.05).The Alb level in the PLA2R antibody-positive group was significantly lower than that in the negative group(P < 0.01), the 24hUpro level in the PLA2R-positive group was significantly higher than that in the negative group(P < 0.05), and the differences were statistically significant.ConclusionsThe detection of PLA2R, THSD7A and their antibodies can contribute to the diagnosis and classification of membranous nephropathy.The level of PLA2R antibody can reflect the disease activity and can be used to evaluate treatment effect.The incidence rate of THSD7A-related MN in membranous nephropathy patients is relatively low.