磷脂酶A2受体及1型血小板反应蛋白7A域在特发性膜性肾病中的表达及意义

Expression and significance of phospholipase A2 receptor and thrombospondin type-1 domain 7A in idiopathic membranous nephropathy

目的探讨磷脂酶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)在特发性膜性肾病(idiopathic membranous nephropathy,IMN)的表达及意义。方法免疫组织化学法检测MN患者肾组织PLA2R(G-PLA2R)和肾组织THSD7A(G-THSD7A)的表达,同时应用酶联免疫吸附法检测血清PLA2R(S-PLA2R)及血清THSD7A(S-THSD7A)的水平,评价二者在IMN的诊断价值。结果纳入的153例IMN患者的G-PLA2R阳性率为56.2%,G-PLA2R阳性组的IgG4阳性率为69.8%;G-THSD7A阳性率为4.6%,G-THSD7A阳性组的IgG4阳性率为85.7%。进行血清抗体检测的36例IMN患者中S-PLA2R、S-THSD7A阳性率分别为69.4%、5.6%。采用G-PLA2R、G-THSD7A、G-PLA2R+IgG4、G-THSD7A+IgG4诊断IMN的灵敏度分别为56.2%、4.6%、39.2%、3.9%,特异度分别为65.2%、100%、78.3%、100%。结论G-PLA2R和S-PLA2R在IMN患者中均有一定的阳性表达率,为IMN的特异性诊断指标,且与肾组织中IgG4联合检测可提高诊断特异度;G-THSD7A和S-THSD7A在IMN患者中的表达率很低,可作为IMN补充的特异性诊断指标。

Objective To investigate expression and significance of phospholipase A2 receptor(PLA2R)and thrombospondin type-1 domain 7A(THSD7A)in idiopathic membranous nephropathy(IMN).Methods Immunohistochemistry was used to detect the expression of glomerular phospholipase A2 receptor(G-PLA2R)and glomerular thrombospondin type-1 domain 7A(G-THSD7A)in the renal tissue in MN patients,and serum PLA2R(S-PLA2R)and serum thrombospondin type-1 domain 7A(S-THSD7A)levels were detected with enzyme-linked immunosorbent assay(ELISA)so as to evaluate the diagnostic value for IMN.Results The positive expression rate of G-PLA2R in 153 IMN patients included in this study was 56.2%,the positive rate of IgG4 in the G-PLA2R positive group was 69.8%;the positive expression rate of G-THSD7A was 4.6%,and the positive rate of IgG4 in the G-THSD7A positive group was 85.7%.Detection of serum S-PLA2R and S-THSD7A in 36 IMN patients showed that the positive rates of S-PLA2R and S-THSD7A were 69.4%and 5.6%respectively.The sensitivity values of G-PLA2R,G-THSD7A,G-PLA2R+IgG4,and G-THSD7A+IgG4 for the diagnosis of IMN were 56.2%,4.6%,39.2%,and 3.9%,respectively;and the specificity values were 65.2%,100%,78.3%,and 100%,respectively.Conclusions Glomerular PLA2R and serum PLA2R have a certain positive expression rate in IMN patients,and are specific diagnostic indices for IMN.Its combination with glomerular IgG4 can improve the diagnostic specificity.The expression rates of glomerular THSD7A and serum THSD7A are very low in IMN patients,and can be used as specific and supplementary diagnostic indicators for IMN.