伴IgA沉积的儿童微小病变肾病的临床病理特征及预后

Clinicopathological features and prognosis of minimal change nephropathy with IgA deposition in children

目的分析伴IgA沉积的儿童微小病变肾病（MCD-IgA）的临床病理特征及预后。方法回顾性分析2010年1月至2015年12月在南京医科大学附属儿童医院收治的10例MCD-IgA患儿的临床及病理资料，并选取24例微小病变肾病综合征（MCD-NS）及21例临床表现为肾病综合征的IgA肾病（NS-IgAN）作为对照，分析3组患儿临床表现、病理特征及预后差异。结果1．临床表现：MCD-IgA组在起病年龄、性别、血尿发生率、24 h尿蛋白水平、血清清蛋白及胆固醇水平、血清IgA升高比例方面与MCD-NS组比较差异均无统计学意义。但NS-IgAN组起病年龄较MCD-IgA组及MCD-NS组大[（8.6±2.1）岁比（4.8±2.4）岁、（4.0±1.6）岁]，血清清蛋白水平较MCD-IgA组及MCD-NS组高[（22.8±4.3） g/L比（19.0±1.9） g/L、（16.8±3.0） g/L]，血清总胆固醇水平低于MCD-IgA组及MCD-NS组[（7.9±1.9） mmol/L比（9.9±2.7） mmol/L、（9.8±2.1） mmol/L]，以上差异均有统计学意义（均P〈0.05），且均合并肉眼血尿。2.病理表现：MCD-IgA组及MCD-NS组光镜下病变均较轻微，但NS-IgAN组光镜病变较重（系膜增生基础上常合并内皮增生、节段或球性硬化、新月体、襻坏死及肾小管间质慢性病变）；免疫荧光MCD-NS组基本阴性，MCD-IgA组IgA沉积强度较弱（≤＋＋），仅3例（30.0%）合并C3沉积，而NS-IgAN组IgA沉积强度较强（≥＋＋＋），且多数合并C3及其他免疫球蛋白沉积；电镜下MCD-IgA组及MCD-NS组主要表现为足突广泛融合，MCD-IgA 9例系膜区见少量电子致密物沉积。而NS-IgAN组主要为系膜区大量电子致密物沉积，仅8例（38.0%）足突融合〉50%。3.预后：MCD-IgA组9例激素依赖或频复发，1例激素耐药，6例加用其他免疫抑制剂，除1例失访外，平均随访（61.5±28.8）个月，8例获得完全缓解；MCD-NS组20例激素依赖或频复发，4例激素耐药，23例加用其他免疫抑制剂，平均随访（36.4±12.5）个月，22例（91.7%）获得完全缓解；NS-IgAN组均表现为激素耐药，均加用环磷酰胺冲击治疗，平均随访（38.6±15.2）个月，19例（90.5%）完全缓解。结论MCD-IgA患儿临床表现及预后与MCD-NS相似，但其临床及病理表现与NS-IgAN存在明显不同。推测MCD-IgA本质还是属于微小病变，IgA沉积可能系非特异性。

Objective To analyze the clinicopathological features and prognosis of minimal change nephropathy with IgA deposition （MCD -IgA） in children. Methods The clinical and pathological data of 10 cases in Children＇s Hospital of Nanjing Medical University from January 2010 to December 2015 with MCD - IgA were retrospectively analyzed, and 24 cases of minimal change nephrotic syndrome （MCD -NS） and 21 cases of IgA nephropathy clini- cally manifested with nephrotic syndrome （ NS - IgAN） were selected as controls. Results （ 1 ） Clinical manifestations ： there were no significant differences in age, gender, incidence of hematuria, level of 24 hours urine protein, serum albumin and cholesterol levels and elevated serum IgA ratio in MCD - IgA compared with MCD - NS group. Compared with MCD - IgA and MCD - NS, NS - IgAN group showed older age of onset [ （ 8.6 ± 2.1 ） years vs. （4.8 ± 2.4 ） years, （4.0 ± 1.6） years ], higher level of serum albumin [ （22.8 ± 4.3 ） g/L vs. （ 19.0 ± 1.9 ） g/L, （ 16.8 ± 3.0 ） g/L ], and lower level of serum total cholesterol [ （7.9 ± 1.9 ） mmol/L vs. （9.9 ± 2.7 ） mmol/L, （9.8 ± 2.1 ） mmol/L ], and all the differences were significant（ all P 〈 0.05 ）. NS- IgAN group was all associated with gross hematuria. （2） Pathology ： the light microscope lesions in MCD - IgA and MCD - NS group were mild, but it was usually associated with severe histologic lesions in NS - IgAN, such as endocapillary proliferation, segmental sclerosis, crescent formation, tuft necrosis and chronic tubulointerstitial lesions ; in MCD - NS group, immunofluorescence was negative. In MCD - IgA group, IgA deposition intensity was weak （ less than ＋＋ ）, and 3 cases （ 30.0% ） were accompanied with C3 deposition. In NS - IgAN group, IgA deposition intensity was stronger （ more than ＋＋＋ ） ,and most of the eases were accompartied with C3 and other immunoglobulins deposition. Under electron microscope, both MCD - IgA and MCD - NS showed wide foot process effacement,and a small amount of mesangial electron dense deposit was detected in 9 cases of MCD- IgA. In NS - IgAN group, large amount of electron dense deposit was found in the mesangial region, and only 8 cases （ 38.0% ） showed more than 50% of foot process effacement. （ 3 ） Prognosis： in MCD - IgA group, 9 patients were steroid -dependent or frequently relapsed, 1 case showed steroid -resistance,6 patients required additional agents. Except 1 case lost ,with an average of （61.5 ±28. g ） months were followed up, g patients achieved complete remission; In MCD- NS group,20 cases were steroid- dependent or frequently relapsed,4 cases were steroid -resistant,23 cases required additional immunosuppressive agents. Followed up for an average of （36.4 ± 12.5 ） months, 22 cases （91.7 % ） achieved complete remission ;In NS- IgAN group, all cases were steroid -resistant and combined with cyclophospha- mide treatment;followed up for an average of （38.6 ±15.2） months, 19 cases （90.5%） achieved complete remission. Conclusions The clinical manifestations and prognosis of MCD - IgA were similar to MCD - NS, but the clinical and pathological findings of MCD - IgA were different from those of NS - IgAN. It is deduced that the nature of MCD - IgA is still a MCD, and that the IgA deposition may be nonspecific.