肾移植术后IgA肾病复发并非总是良性预后

目的  探讨肾移植后IgA肾病(IgAN)复发的临床病理特征及其预后。方法  选取1996年1月至2009年4月期间在南京军区南京总医院国家肾脏疾病临床医学研究中心接受肾移植的148例IgAN终末期肾衰竭受者为研究对象。根据肾移植后有否IgAN复发分为IgAN复发组(46例)和非IgAN复发组(102例)。比较IgAN复发组和非IgAN复发组受者肾移植术后0、1、2、3、5年尿沉渣红细胞(U-RBC)计数、24 h尿蛋白定量、肾功能[血清肌酐(Scr)、肾小球滤过率(GFR)]; 比较两组受者术后移植肾病理组织学损伤的发生率和移植肾存活率。结果  IgAN复发组肾移植术后U-RBC计数、24 h尿蛋白定量逐渐增加, 肾功能逐渐变差。与非IgAN复发组比较, IgAN复发组术后2、3、5年的U-RBC计数明显增加, 术后5年的肾功能明显较差(均为P < 0.01~0.001)。移植肾病理学结果示, 与非IgAN复发组比较, IgAN复发组的细胞性新月体形成、肾小球粘连、系膜细胞增生、系膜基质增多、球性硬化、肾小球节段硬化、球性废弃和肾间质纤维化等的发生率均明显升高(均为P < 0.001)。IgAN复发组和非IgAN复发组的慢性移植肾损伤指数分别为7.7±2.3和4.6±1.4(P < 0.01)。与非IgAN复发组比较, IgAN复发组的慢性排斥反应发生率、移植肾肾小球病(不包括IgAN)和C4 d沉积阳性发生率均较高(P < 0.01~0.001)。IgAN复发组和非IgAN复发组肾移植术后1年移植肾存活率分别为93.8%和95.6%(P>0.05), 术后3年分别为86.7%和88.3%(P>0.05), 术后5年分别为51.4%和83.8%(P < 0.001)。IgAN复发组中10例(22%)患者和非IgAN复发组中9例(9%)患者发生移植肾丧失。结论  肾移植术后IgA肾病复发以无症状性镜下血尿、蛋白尿和肾功能呈进行性下降为特征, 会降低移植肾长期存活率, 提示预后不良。

Recurrent IgA nephropathy after renal transplantation: not always a benign prognosis

Objective To discuss the clinicopathological characteristics and prognosis of the recurrence of IgA nephropathy (IgAN) after renal transplantation. Methods A total of 148 patients, pathologically diagnosed with IgAN which progressed into end-stage renal failure, undergoing renal transplantation in National Clinical Medical Research Center of Kidney Diseases, Nanjing General Hospital of Nanjing Military Command from January 1996 to April 2009, were included in this study.According to whether IgAN recurred, all patients were assigned into recurrence (n=46) and non-recurrence groups (n=102). Urinary red blood cell (U-RBC) count, 24 h urinary protein level, renal function including serum creatinine (Scr) and glomerular filtration rate (GFR) at 0, 1, 2, 3 and 5 years after renal transplantation were statistically compared between two groups. The incidence of histopathological renal injury and survival rate of transplant kidneys was compared between two groups. Results In recurrence group, U-RBC count and 24 h urinary protein level were gradually elevated and renal function steadily declined. Compared with non-recurrence group, U-RBC count at 2-, 3-and 5-year after renal transplantation significantly increased, and renal function was significantly aggravated at postoperative 5 years (all in P < 0.01-0.001) in recurrence group. Renal pathological findings revealed that compared with non-recurrence group, the incidence of cellular crescent formation, glomerulus adhesion, mesangial cell proliferation, increased mesentery matrix, glomerulosclerosis, segmental glomerulosclerosis, glomerular dysfunction and tubulointerstitial fibrosis was significantly higher in recurrence group (all in P < 0.001). After renal transplantation, chronic kidney injury index in recurrence group was 7.7±2.3, which was significantly higher than 4.6±1.4 in non-recurrence group (P < 0.01). Compared with non-recurrence group, the incidence of chronic rejection, glomerulopathy of transplant kidney(without IgAN) and positive C4d deposition was significantly higher in recurrence group (P < 0.01-0.001). At 1-and 3-year after renal transplantation, survival rates of transplant kidney did not significantly differ between recurrence and non-recurrence groups(93.8% vs. 86.7%, 95.6% vs. 88.3%, both in P>0.05). However, the survival rate at 5 years after transplantation was 51.4% in recurrence group, significantly lower compared with 83.8% in non-recurrence group (P < 0.001). In recurrence group, 10 patients (22%) presented with renal failure after renal transplantation, and 9 patients(9%) in non-recurrence group. Conclusions After renal transplantation, the recurrence of IgAN characterized by asymptomatic microscopic hematuria, albuminuria and progressive aggravation of renal function reduce long-term survival rate of renal graft and indicate poor prognosis.