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膜性肾病(membranous nephropathy, MN)发病率在不断增加[1]。其发病机制主要是由于肾小球足细胞抗原与其相应的自身抗体结合形成免疫复合物沿肾小球基底膜沉积,继而引起足细胞损伤的自身免疫性疾病[2]。MN分为特发性MN(idiopathic membranous nephropathy, IMN)和继发性MN(secondary membranous nephropathy, SMN)。IMN没有可识别的基础疾病,SMN则可能与自身免疫性疾病、药物、感染、恶性肿瘤等有关[2]。80%的IMN病人出现肾病综合征,20%为非肾病性蛋白尿,临床预后各异,可表现为自发缓解或治疗后缓解、持续蛋白尿、肾功能进行性减退[3]。研究[2, 4-5]已证实M型磷脂酶A2受体(phospholipase A2 receptor, PLA2R)和1型血小板反应蛋白7A域(thrombospondin type 1 domain-containing 7A, THSD7A)是IMN的靶抗原,PLA2R和THSD7A相关MN分别占原发性MN病人的约70%和1%~5%,在IMN诊断及病情监测中具有重要临床意义。本研究收集172例IMN病人病历资料并分析,探讨皖北地区IMN病人肾小球PLA2R和THSD7A及两者血清抗体水平检测在MN中的诊断价值及预后分析。
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选取2020年1月至2021年11月蚌埠医学院第一附属医院肾病科行肾活检确诊的172例IMN病人为研究对象,男118例,女54例,年龄20~71岁。排除SMN、有严重合并症者。另外选取同期肾活检病理确诊的SMN组7例,男5例,女2例,年龄27~52岁,其中乙型病毒性肝炎相关肾炎1例,狼疮性肾炎3例,1例合并MPO阳性,2例非典型膜未明确病因。2组性别、年龄、血肌酐(SCr)、血白蛋白(Alb)、24 h尿蛋白定量(24hUpro)肾小球滤过率(eGFR)等一般资料比较差异均无统计学意义(P>0.05)(见表 1)。
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) 糖尿病 收缩压/mmHg 舒张压/mmHg IMN组 172 118 54 49.69±11.82 25.68±6.26 4.61±2.22 74.26±26.45 107.98±23.14 8 134.72±16.45 85.80±12.79 SMN组 7 5 2 43.57±10.29 22.64±4.77 3.75±1.71 76.14±31.55 112.62±29.61 1 130.86±21.71 78.86±18.06 t — 0.07* 1.35 1.27 1.01 0.18 0.51 0.07* 0.60 1.39 P — >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 *示校正χ2值 表 1 2组一般资料比较(x±s)
MN诊断标准[2]:依靠肾活检,光镜下可见基底膜病变,钉突形成,免疫荧光见IgG呈球性沉积,电镜下肾小球毛细血管袢上皮侧大量免疫复合物沉积(见图 1、2);IMN没有可识别的基础疾病,SMN则常见于自身免疫性疾病、药物、感染、恶性肿瘤。本研究经本院伦理委员会批准。
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SCr、Alb、24hUpro等临床资料,均由我院全自动生化分析仪测定(贝克曼库尔特公司,AU5800型)。CKD-EPI公式计算eGFR。ELISA法检测PLA2R和THSD7A抗体,肾组织PLA2R及THSD7A抗原检测采用免疫荧光法测定,沿毛细血管袢呈颗粒样沉积为免疫荧光阳性表现;PLA2R和THSD7A及抗体检测均由合肥金域医学实验室有限公司完成。
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采用t(或t′)检验、χ2检验、Fisher′s确切概率法和Spearman相关分析。
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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)(见表 2)。
分组 n 单纯PLA2R阳性 THSD7A阳性 否 是 否 是 IMN组 172 5 167 167 5 SMN组 7 4 3 7 0 P — < 0.01# 1.00# #示Fisher′s确切概率法 表 2 2组病人肾组织PLA2R和THSD7A阳性率比较(n)
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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)。5例THSD7A阳性病人及SMN组病人血清中未检测出抗体(见表 3)。
分组 n PLA2R-Ab THSD7A-Ab 阴性 阳性 阴性 阳性 IMN组 172 29 143 172 0 SMN组 7 5 2 7 0 χ2 — 9.71* — P — < 0.01 — *示校正χ2值 表 3 2组病人血清PLA2R抗体和THSD7A抗体阳性率比较(n)
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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)(见表 4)。
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) PLA2R+THSD7A 167 3 2 50.40±16.13 25.32±3.71 4.60±2.25 90.60±37.02 92.73±38.05 单纯PLA2R阳性 5 115 52 49.66±11.74 25.69±6.32 4.81±1.12 73.77±26.07 108.44±22.57 t — 0.00* 0.10 0.13▽ 0.21 1.00 0.92 P — >0.05 >0.05 >0.05 0.834 >0.05 >0.05 ▽示t′值;*示χ2值 表 4 单纯PLA2R阳性和PLA2R/THSD7A双阳组病人基本资料比较(x±s)
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相关性分析结果显示,PLA2R-Ab与SCr、eGFR之间无相关关系(P>0.05),与Alb之间存在显著负相关关系(P < 0.01),与24hUpro之间存在正相关关系(P < 0.05)(见表 5)。
指标 PLA2R-Ab Alb -0.256** 24hUpro 0.187* SCr 0.116 eGFR -0.136 *P < 0.05,**P < 0.01 表 5 PLA2R-Ab与24hUpro、Alb、SCr、eGFR相关性分析(r)
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2组病人性别、年龄、SCr、eGFR水平比较,差异均无统计学意义(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), 差异均有统计学意义(见表 6)。
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) PLA2R-Ab阴性 29 19 10 51.10±8.74 30.59±7.71 3.80±2.05 69.35±14.78 110.75±18.48 PLA2R-Ab阳性 143 99 44 49.40±12.36 24.69±5.43 4.77±2.22 75.26±28.17 107.42±23.99 t — 0.15 0.88▽ 3.93▽ 2.19 1.63 0.70 P — >0.05 >0.05 < 0.01 0.03 >0.05 >0.05 ▽示t′值 表 6 IMN组PLA2R抗体阳性病人与阴性病人基本资料比较(x±s)
PLA2R和THSD7A在特发性膜性肾病中的临床应用评价
Evaluation on clinical application of PLA2R and THSD7A in idiopathic membranous nephropathy
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摘要:
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。 -
关键词:
- 特发性膜性肾病 /
- 磷脂酶A2受体 /
- 1型血小板反应蛋白7A域
Abstract: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. -
表 1 2组一般资料比较(x±s)
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) 糖尿病 收缩压/mmHg 舒张压/mmHg IMN组 172 118 54 49.69±11.82 25.68±6.26 4.61±2.22 74.26±26.45 107.98±23.14 8 134.72±16.45 85.80±12.79 SMN组 7 5 2 43.57±10.29 22.64±4.77 3.75±1.71 76.14±31.55 112.62±29.61 1 130.86±21.71 78.86±18.06 t — 0.07* 1.35 1.27 1.01 0.18 0.51 0.07* 0.60 1.39 P — >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 *示校正χ2值 表 2 2组病人肾组织PLA2R和THSD7A阳性率比较(n)
分组 n 单纯PLA2R阳性 THSD7A阳性 否 是 否 是 IMN组 172 5 167 167 5 SMN组 7 4 3 7 0 P — < 0.01# 1.00# #示Fisher′s确切概率法 表 3 2组病人血清PLA2R抗体和THSD7A抗体阳性率比较(n)
分组 n PLA2R-Ab THSD7A-Ab 阴性 阳性 阴性 阳性 IMN组 172 29 143 172 0 SMN组 7 5 2 7 0 χ2 — 9.71* — P — < 0.01 — *示校正χ2值 表 4 单纯PLA2R阳性和PLA2R/THSD7A双阳组病人基本资料比较(x±s)
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) PLA2R+THSD7A 167 3 2 50.40±16.13 25.32±3.71 4.60±2.25 90.60±37.02 92.73±38.05 单纯PLA2R阳性 5 115 52 49.66±11.74 25.69±6.32 4.81±1.12 73.77±26.07 108.44±22.57 t — 0.00* 0.10 0.13▽ 0.21 1.00 0.92 P — >0.05 >0.05 >0.05 0.834 >0.05 >0.05 ▽示t′值;*示χ2值 表 5 PLA2R-Ab与24hUpro、Alb、SCr、eGFR相关性分析(r)
指标 PLA2R-Ab Alb -0.256** 24hUpro 0.187* SCr 0.116 eGFR -0.136 *P < 0.05,**P < 0.01 表 6 IMN组PLA2R抗体阳性病人与阴性病人基本资料比较(x±s)
分组 n 男 女 年龄/岁 Alb/(g/L) 24hUpro/(g/24 h) SCr/(μmol/L) eGFR/(mL·min-1·1.73 m-2) PLA2R-Ab阴性 29 19 10 51.10±8.74 30.59±7.71 3.80±2.05 69.35±14.78 110.75±18.48 PLA2R-Ab阳性 143 99 44 49.40±12.36 24.69±5.43 4.77±2.22 75.26±28.17 107.42±23.99 t — 0.15 0.88▽ 3.93▽ 2.19 1.63 0.70 P — >0.05 >0.05 < 0.01 0.03 >0.05 >0.05 ▽示t′值 -
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