伴IgA沉积的特发性膜性肾病的临床病理特征

Clinicopathological characteristics of idiopathic membranous nephropathy with IgA deposition

目的探讨伴IgA沉积的特发性膜性肾病(IMN)的临床病理特征。方法选取1993年5月至2018年8月在北京大学第三医院就诊的伴IgA沉积的52例IMN患者为IMN伴IgA组,IMN伴IgA组按IgA是否沉积在系膜区又分为系膜区亚组(30例)和非系膜区亚组(22例);匹配年龄和性别的IMN和IgA肾病患者各52例,分别为IMN对照组和IgAN对照组,比较肾穿刺时的临床病理资料。结果与IMN对照组比较,IMN伴IgA组的血IgG更高(P=0.005),两组水肿比例、血尿比例、24 h尿蛋白定量、血白蛋白、高血压比例及抗核抗体阳性比例等比较,差异均无统计学意义(均P>0.05)。IMN伴IgA组共检测血抗PLA2R抗体21例,IMN伴IgA组与IMN对照组的滴度比较,差异无统计学意义(P=0.130)。与IgAN对照组比较,IMN伴IgA组的尿蛋白定量更多、血白蛋白更低,血胆固醇及水肿比例更高,血尿比例更低,且血IgA水平更低(均P<0.05)。系膜区亚组与非系膜区亚组的高血压比例比较,差异无统计学意义(P=0.328)。系膜区亚组与非系膜区亚组的水肿比例、血尿、24 h尿蛋白定量、血白蛋白、滴度等比较,差异均无统计学意义(均P>0.05);与IMN对照组、IgAN对照组比较,IMN伴IgA组患者的肾IgM、FRA、C1Q沉积阳性率更高(P<0.05)。三组患者均有系膜细胞和基质的增生,IMN对照组最轻,IgAN对照组最重,IMN伴IgA组居中,三组比较差异有统计学意义(P<0.01)。IMN伴IgA组与IMN对照组的新月体阳性率比较,差异无统计学意义(P=1.000)。与IgAN对照组比较,IMN伴IgA组的新月体阳性率更高[2例(3.8%)vs.16例(30.8%),P<0.001]。系膜区亚组仅系膜细胞及基质轻中度增生程度重于非系膜区亚组(P<0.001)。结论IMN伴IgA沉积患者中老年高发,以大量蛋白尿为主要表现,肾小球源性血尿不突出,与IMN临床表现相似,与IgA肾病临床差异较大。

Objective To investigate the clinicopathological features of idiopathic membranous nephropathy(IMN)with IgA deposition.Methods Fifty-two IMN patients with IgA deposition who were admitted to Peking University Third Hospital from May 1993 to August 2018 were selected as IMN and IgA group.IMN and IgA group were divided into mesangial subgroup(30 cases)and non-mesangial subgroup(22 cases)according to whether IgA deposition was in mesangial region.Fifty-two patients with IMN and IgA nephropathy were matched with age and sex,respectively,as IMN control group and IgAN control group,and the clinicopathological data at renal puncture were compared.Results Compared with IMN control group,IMN combined with IgA group had higher blood IgG(P=0.005).There were no significant differences in edema ratio,hematuria ratio,24 h urine protein quantity,proportion of hypertension,positive proportion of antinuclear antibody and blood albumin between IMN and IgA group and IMN control group(all P>0.05).A total of 21 cases of blood anti-PLA2R antibody were detected in IMN and IgA group,and there was no significant difference in titer between IMN and IgA group(P=0.130).Compared with IgAN control group,IMN combined with IgA group had more urinary protein,lower blood albumin,higher blood cholesterol and edema ratio,lower hematuria ratio and lower blood IgA level(all P<0.05).There was no significant difference in the proportion of hypertension between the mesangial subgroup and the non-mesangial subgroup(P=0.328).There were no significant differences in edema ratio,hematuria,24 h urine protein quantity and serum albumin between the mesangial subgroup and the non-mesangial subgroup(all P>0.05).Compared with IMN control group and IgAN control group,the positive rates of renal IgM,FRA and C1Q deposition were higher in IMN combined with IgA group(P<0.05).The proliferation of mesangial cells and matrix was observed in all the three groups,the least in the IMN control group,the most in the IgAN control group,and the IMN combined with IgA group was in the middle,with statistical differences among the three groups(P<0.01).There was no significant difference in the positive rate of crescent body between IMN and IgA group and IMN control group(P=1.000).Compared with the IgAN control group,the positive rate of crescent body was higher in the IMN and IgA group[2(3.8%)vs.16(30.8%),P<0.001].The proliferation degree of mesangial cells and matrix in the mesangial subgroup was heavier than that in the non-mesangial subgroup(P<0.001).Conclusions The incidence of IMN with IgA deposition is high in middle-aged and elderly patients,with abundant proteinuria as the main manifestation,and glomerulogenic hematuria is not prominent,which is similar to the clinical manifestations of IMN,but significantly different from IgA nephropathy.