摘要：
Objective To investigate the expressions of IgG subtypes and M-type phospholipase A2 receptor (PLA2R) in membranous nephropathy (MN), and to retrospectively analyze its significance and value of differential di-agnosis in idiopathic membranous nephropathy (IMN) and undetermined atypical membranous nephropathy (UAMN). Methods A total of 120 cases of membranous nephropathy diagnosed by renal biopsy pathology (immunofluores-cence, light microscopy, and electron microscopy) in our hospital between February and September, 2015 were includ-ed in the study. The expressions of IgG subtypes and PLA2R were determined by immunohistochemistry, and retro-spectively analyzed, combined with the clinical data and pathological features. Their value in the differential diagnosis of IMN and UAMN was evaluated. Results ①A total of 120 cases were included, that IMN accounted for 69.2%and UAMN accounted for 30.8%. The average age of onset in the UAMN group was lower than that in the IMN group, and the difference was statistical significance, whereas no statistical difference was found in the level of urinary protein be-tween the two groups. ②The positive rates of IgA, IgM, C3, FRA, and C1q in the UAMN group were higher than those in the IMN group, and there were statistical differences in the expressions of IgA and complement C1q between the two groups. ③Positive IgG4 was mainly expressed in IMN group that the positive rate of IgG4 was significantly higher than the other IgG subtypes, and there was statistical difference between the IMN group and the UAMN group. In the UAMN group, positive IgG1 and IgG2 were highly expressed. The positive rate of IgG4 in the UAMN group was significantly lower than that in the IMN group. ④The positive rate of PLA2R was significantly higher than all IgG subtypes in the IMN group, and there was statistical difference between the IMN group and the UAMN group. ⑤In the evaluation of the value of IMN and UAMN by the differential diagnosis of IgG4 and PLA2R expression, the inten-sity baseline, sensitivity and specifity of IgG4 were 1, 79. 5%, and 59.5%, respectively. The intensity baseline, sensi-tivity and specifity of PLA2R were >1, 90.4%, and 35.1%, respectively. After the evaluation of IgG4 and PLA2R, the sensitivity and specifity were 71.1%and 64.9%, respectively. Conclusion①Determined by immunohistochemistry assay, IgG4 is mainly expressed in IMN group, whereas IgG subtypes, IgG1, IgG2 and IgG4 are highly expressed in UAMN group. ②PLA2R and IgG4 in IMN group show a high positive concordance rate. The application of IgG4 and PLA2R contribute to the differential diagnosis of IMN and UAMN.%目的：通过观察IgG亚型及M型磷脂酶A2受体（PLA2R）在膜性肾病中的表达，回顾性分析二者在特发性膜性肾病（IMN）与病因不明的不典型膜性肾病（UAMN）中的表达意义及鉴别诊断价值。方法收集我中心于2015年2月至9月经肾穿刺活检病理（免疫荧光、光镜、电镜）确诊为膜性肾病120例，对其进行免疫组织化学IgG亚型及PLA2R表达的观察分析，结合其临床资料及病理学特点，进行回顾性统计分析，评价它们在IMN和UAMN鉴别诊断中的价值。结果①共收集病例120例，其中IMN 占69．2％，UAMN占30．8％；UAMN组的平均发病年龄低于IMN组，差异具有统计学意义，组间蛋白尿水平差异无统计学意义。②UAMN组IgA、IgM、C3、FRA、C1q的阳性率均高于IMN组，且IgA及补体C1q的表达中组间差异有统计学意义。③IMN组以IgG4阳性为主，阳性率显著高于其他亚型，且与UAMN组差异有统计学意义；UAMN组IgG1、IgG2均具有较高比例的阳性沉积，IgG4的阳性率明显低于IMN组。④IMN组PLA2R的阳性率显著高于IgG各亚型，且与UAMN组差异有统计学意义。⑤IgG4与PLA2R联合表达鉴别诊断IMN与UAMN的价值评估中，IgG4以强度1为界值，灵敏度为79．5％，特异度为59．5％；PLA2R以强度＞1为界值，灵敏度为90．4％，特异度为35．1％；二者联合评价后，灵敏度为71．1％，特异度为64．9％。结论①经免疫组织化学方法测定，IMN组以IgG4沉积为主，而UAMN组存在IgG1、IgG2、IgG4多种亚型的沉积；②PLA2R和IgG4在IMN组具有较高的阳性一致率；IgG4与PLA2R联合应用，有助于IMN与UAMN的鉴别诊断。
