The aetiology and pathogenesis of chronic allograft nephropathy

Renal transplantation is the ultimate form of renal replacement therapy, and is the treatment of choice for many patients with end-stage renal failure. The advent of calcineurin inhibitor based immunosuppression resulted in the 1-year renal allograft failure rate dropping from around 50% twenty years ago to less than 10% in more recent times. Despite a massive improvement in renal allograft survival in the first year following transplantation 10-year graft survival can be as low as 50%. Chronic allograft nephropathy (CAN) is recognised as the main cause of renal allograft failure following the first year after transplantation. The diagnosis of CAN can only be made histologically. Typically biopsy specimens in grafts with CAN demonstrate an overall fibrotic appearance effecting the vascular endothelium, renal tubules, interstitium, and glomerulus. The risk factors for CAN are divided into alloimmune and alloimmune independent. Alloimmune dependent factors include acute cellular rejection, severity of rejection, subclinical rejection and HLA mismatch. Alloimmune independent factors such as delayed graft function, donor age, Cytomegalovirus infection, donor/recipient co-morbidity and of course calcineurin inhibitor toxicity are important in the development of CAN. The pathogenesis of CAN is complex, multifactorial, and unfortunately incompletely understood. There are a number of pivotal steps in the initiation and propagation of the fibrosis seen in biopsy specimens from kidneys with CAN. Endothelial activation in response to one or more of the aforementioned risk factors stimulates leukocyte activation and recruitment. Recruited leukocytes subsequently infiltrate through the endothelium and induce key effector cells to secrete excessive and abnormal extracellular matrix (ECM). Enhanced deposition of ECM is a histological hallmark of CAN. This paper aims to present a concise yet accurate and up-to-date review of the literature concerning the aetiological factors and pathological processes which are present in the generation of CAN.     

将钙调磷酸酶抑制剂转换为西罗莫司在慢性移植肾肾病中的临床治疗效果

目的 探讨慢性移植肾肾病(CAN)患者将免疫抑制方案中钙调磷酸酶抑制剂(CNI)转换为西罗莫司(SRL)的有效性及安全性.方法 选取72例经移植肾活检证实发生CAN的受者,其中35例将免疫抑制方案中CNI转换为SRL(SRL组),其余37例继续原CNI方案(CNI组).另取10例因其他原因将CNI转换为SRL治疗的受者,将45例转换为SRL的患者分为A组[血肌酐(SCr)＜120 μmol/L),B组(SCr为120～200 μol/L,且Banff分级为Ⅰ～Ⅱ级),C组(SCr为120～200 μmol/L,且Banff分级在Ⅱ级以上),D组(SCr＞200 μmol/L).随访期为24个月,检测各组随访期内的各临床指标.结果 转换治疗前,两组间SCr和肾小球滤过率(eGFR)的差异无统计学意义(P＞0.05);转换治疗后24个月内,SRL组SCr水平和eGFR较CNI组明显改善(P＜0.05),而CNI组的移植肾功能有逐渐衰退的趋势.SRL组尿蛋白及血脂明显上升(P＜0.05),而CNI组变化不大;SRL组血小板计数较CNI组明显下降(P＜0.05),两组间其他指标的差异无统计学意义(P＞0.05).A组患者各指标在转换治疗前后的变化并不大,B组患者的肾功能及蛋白尿有改善明显,C组和D组患者肾功能有不同程度衰退情况,且蛋白尿加重.结论 SRL转换治疗对于稳定及改善CAN患者的移植肾功能是有效、安全的,CAN早期进行转换(SCr＜200 μmol/L)效果明显.     

Protective effects of atorvastatin on chronic allograft nephropathy in rats

OBJECTIVE: Chronic allograft nephropathy (CAN) is the leading cause of late kidney allograft loss. Recent studies have suggested that atorvastatin (ATO) may interact with the acute inflammatory process in the renal interstitium and suppress the proliferation of mesangial cells. We hypothesized that ATO could also inhibit the chronic inflammatory process and prevent the progression of CAN. MATERIALS AND METHODS: Fisher (F344) kidneys were orthotopically transplanted into Lewis rat recipients. Lewis-to-Lewis rat kidney transplantation was served as the syngeneic control (Syn group). Allograft recipients were randomized and treated with cyclosporine A alone (Allo group) or in combination with ATO (15 or 30 mg/kg/d intrgastric, respectively, the low dose treatment group/high dose treatment group [LT/HT] groups). Renal function and the urine protein excretion were analyzed. Animals were sacrificed 20 weeks posttransplantation for histological and immunohistochemical studies, as well as analysis of mRNA levels of cytokines and chemokines. RESULTS: Renal function progressively deteriorated and substantial proteinuria developed in the Allo group compared with the Syn group. ATO-treated rats had significantly higher creatinine clearance rate and less amount of proteinuria. Histological examination revealed obvious features of CAN in the Allo group, whereas LT/HT groups demonstrated minimal glomerulosclerosis, interstitial fibrosis, intimal thickening, and tubular atrophy. The numbers of infiltrating mononuclear cells (ED1+, CD8+, and CD68+) decreased markedly, and the intragraft expression of transforming growth factor beta1 (TGF-beta1) and collagen III were also significantly attenuated in the LT/HT groups, as compared with the Allo group. The mRNA levels of proinflammatory cytokines (interleukin-2, interferon-gamma, interleukin-10), chemokines (RANTES, MCP-1), and profibrotic genes (TGF-beta1, collagen III) were significantly down-regulated in ATO-treated rats. CONCLUSION: Atorvastatin showed excellent favorable effects on blocking renal inflammation and fibrosis, and thus, efficiently inhibited the development and progression of CAN, which might improve the long-term survival rate of renal allografts.     

肾小管上皮细胞转分化在慢性移植肾肾病中的作用

目的探讨肾小管上皮细胞-肌成纤维细胞转分化在慢性移植肾肾病(CAN)的发生、发展中的作用。方法36例移植肾穿刺标本分为正常组(N组),CAN组(C组),依Banff 97标准将C组按CANⅠ、Ⅱ、Ⅲ级分为C_1、C_2、C_3组,每组9例。免疫组化染色半定量分析比较α-平滑肌肌动蛋白(α-SMA)、波形蛋白(VIM)、角质蛋白(CK_(AEI/AE3))和转化生长因子β1(TGF-β1)在各组中的表达,线性相关分析TGF—β1和α-SMA、VIM、CK_(AE1/AE3)表达的相关性。结果C_1、C_2、C_3组α-SMA表达积分分别为0．95±0．07、1．78±0．12、2．42±0．31,VIM表达积分分别为0．74±0．05、1．31±0．18、2．34±0．25,组间呈递增趋势,均明显高于N组α-SMA表达积分0．07±0．02、VIM表达积分0．09±0．02(P＜0．05)；移植肾组织中TGF-β1表达与α-SMA、VIM呈正相关(r分别为0．73、0．68,P＜0．05),而与CKAE1/AE3表达呈负相关(r=-0．71,P＜0．05)。结论肾小管上皮细胞-肌成纤维细胞转分化参与了CAN的发生、发展,而局部肾组织中TGF-β1的表达上调可能是介导肾小管上皮细胞转分化的重要原因。     

雷帕霉素与他克莫司治疗慢性移植肾肾病

目的 探讨低剂量免疫抑制剂组合治疗慢性移植肾肾病的临床效果. 方法慢性移植肾肾病患者31例,均经临床及部分移植肾穿刺病理证实.术后免疫抑制方案为他克莫司(FK506)、吗替麦考酚酯(MMF)、泼尼松(Pred)三联免疫抑制治疗.调整免疫抑制剂方案为雷帕霉素(RAPA)加低剂量FK506+MMF+Pred四联方案.根据血药浓度、血常规、肝肾功能调整免疫抑制剂用量.监测血压、急性排斥反应发生率、血肌酐、肌酐清除率(GFR)、24 h尿蛋白定量.结果 31例随访12个月.28例患者SCr由治疗前(300±21)μmol/L,治疗后降至(215±38)μmol/L,GFR由治疗前(42.54±2.95)ml·s-1/1.73 m2升至(49.98±3.05)ml·s-1/1.73 m2;治疗前后SCr、GFR差异均有统计学意义(P＜0.05).3例SCr 416～464μmol/L者治疗后SCr仍进行性上升,恢复血液透析治疗.30例24 h尿蛋白定量＜0.8 g者应用RAPA后尿蛋白量并不增加,1例24 h蛋白尿由0.95g升至1.29g.人/肾存活率为100%(31/31)、90.3%(28/31).治疗过程中主要不良反应为全血细胞减少和高脂血症.结论 慢性移植肾肾病患者SCr 167～320μmol/L,24 h蛋白尿定量＜0.8 g,采用RAPA加低剂量FK506+MMF+Pred治疗安全、有效.     

环孢素A转换为他克莫司对慢性移植肾肾病患者的治疗效果

目的 探讨由环孢素A(CsA)转换为他克莫司(Tac)为主的免疫抑制方案对慢性移植肾肾病(CAN)患者的治疗效果.方法 选择接受同种肾移植后发生CAN的患者153例,患者肾移植后均采用CsA、吗替麦考酚酯(MMF)及泼尼松(Pred)的免疫抑制方案.根据是否以Tac替换CsA将患者分为两组.(1)CsA组:45例,进入研究后患者维持原免疫抑制方案.(2)Tac组:108例,进入研究后将CsA转换为Tac,停用CsA后立即开始服用Tac,MMF和Pred的用法同CsA组.对所有患者随访12个月,观察人/移植肾存活率、急性排斥反应发生率、移植肾功能、24 h尿蛋白定量、移植肾穿刺病理学活检及免疫抑制剂的不良反应等指标.结果 随访12个月时,CsA组和Tac组患者存活率均为100%,移植肾存活率分别为86.6%和93.5%(P＜0.05);急性排斥反应发生率分别为4.4%(2/45)和3.7%(4/108)(P＞0.05),6例发生急性排斥反应的患者均经甲泼尼龙冲击治疗3 d后逆转.Tac组患者移植肾功能明显改善,并且出现重度蛋白尿、重度肾间质纤维化和肾小管萎缩的患者比例较CsA组显著减少(P＜0.05).Tac组有13.8%(15例)的患者出现轻度血糖增高,发生率显著高于CsA组的4.4%(2例)(P＜0.05);Tac组有22.2%(24例)的患者发生高血压,发生率显著低于CsA组的55.6%(25例)(P＜0.05);17例因使用CsA而出现牙龈增生和多毛症者,经转换治疗后,症状均明显好转.结论 由CsA转换为Tac为主的免疫抑制方案能够显著改善CAN患者的移植肾功能,延缓CAN的发展,转换过程中未发生严重Tac不良反应并且改善了使用CsA时出现的不良反应.

Abstract：

Objective To investigate the effect of conversion from cyclosporine A (CsA) to tacrolimus (Tac) on chronic allograft nephropathy (CAN). Methods 153 CAN patients undergoing kidney transplantation received CsA, mycophenolate mofetil (MMF) and prednisone (CsA-MMF-Pred) regimen after kidney transplantation, and divided into 2 groups according to whether CsA were maintained in the immunosuppressive regimen: CsA + MMF + Pred group (CsA group, n = 45); Tac + MMF + Pred group (Tac group, n = 108). The patients were followed up with patient/kidney survival rate, acute rejection incidence, renal function, 24-h proteinuria and adverse events of immunosuppressive drugs for 12 months. Results Compared with CsA group, the transplanted kidney survival rate was significantly higher in Tac group (93. 5 % vs 86.6 %, P＜0. 05). Acute rejection (AR) was diagnosed in 4. 4 % (2/45) of recipients in CsA group and 3. 7 % (4/108) in Tac group (P＞0. 05) respectively. Acute rejection (2 cases in CsA group and 4 in Tac group) was reversed by 500 mg of methylprednisolone for consecutive 3 days, and the patients in Tac group showed a significantly lower degree of interstitial fibrosis and tubular atrophy (IF/TA) (P＜0. 05).Renal allograft functions and 24-h proteinuria during a follow-up period of 12 months were significantly improved in Tac group (P ＜ 0. 05). Incidence of mild hyperglycemia in Tac Group (13.8 %, 15/108) was significantly higher than in CsA group (4.4 %, 2/45), and that of hypertension in Tac group (22. 2 %, 24/108) was significantly lower than in CsA group (55.6 %,25/45). CsA-related side effects (such as hirsutism and gingival hypertrophy) in 17 patients were greatly improved after conversion from CsA to Tac treatment. Conclusion The conversion from CsA to Tac on the patients with CAN can improve renal allograft function, retard the progression of renal allograft dysfunction, reduce the incidence of CsA-related side effects and not generate serious adverse effects of Tac.     

Vascular endothelial growth factor in chronic rat allograft nephropathy

BACKGROUND: Chronic allograft nephropathy (CAN) is a complex process of alloimmune responses and chronic inflammation leading to fibrosis and vasculopathy. We examined the biological role of proinflammatory vascular endothelial growth factor (VEGF) in a rat renal transplantation model of CAN. METHODS: Syngraft and allograft recipients were treated with a suboptimal dose of cyclosporine A which allows acute rejection and CAN to develop. Intragraft VEGF, VEGFR-1 and VEGFR-2 expressions were determined at 5, 14, 30 and 60 days. Protein tyrosine kinase inhibitor PTK787 was used to inhibit VEGFR activity. RESULTS: In nontransplanted kidneys and syngrafts, mild VEGF expression was observed in the glomeruli and tubuli. VEGFR-1 was detected in vascular structures and VEGFR-2 in glomeruli as well. In allografts, total intragraft VEGF expression and interstitial inflammatory cell VEGF expression were induced and correlated with the chronic allograft damage index (CADI) score. Total intragraft and interstitial inflammatory cell VEGFR-1 expression was induced and interstitial cell VEGFR-1 expression correlated with the CADI score. Blocking VEGF receptor signaling with PTK787 significantly reduced fibrosis and the CADI score, but did not affect early inflammation or VEGF, VEGFR-1, VEGFR-2 expressions compared to vehicle treated group. CONCLUSIONS: Interstitial inflammatory cell VEGF and VEGFR-1 expressions are induced during the development of CAN. Increased VEGF activity may enhance the alloimmune induced inflammatory responses leading to fibrosis and CAN.     

西罗莫司与钙调磷酸酶抑制剂联合方案在慢性移植肾肾病中的应用

目的 探讨西罗莫司(SRL)与减低剂量的环孢素A(CsA)或他克莫司(Tac)联合方案在慢性移植肾肾病(CAN)中的应用.方法 53例无特定病因所致的CAN患者,在原CsA(或Tac)+吗替麦考酚酯(MMF)+泼尼松(Pred)的免疫抑制方案上加用SRL(四联方案),其中CsA(或Tac)和MMF的用量减少25％～50％.治疗12个月,观察受者血肌酐、肾小球滤过率(GFR)、血胆固醇、血甘油三酯、尿蛋白等的改变.结果 四联方案治疗前患者血肌酐为(161.51±106.48)μmol/L,治疗后1个月为(138.47±67.74) μmol/L,治疗后6个月为(126.51±56.21)μmol/L,治疗后12个月为(123.43±54.18)μmol/L.与治疗前相比较,治疗6个月和12个月后,差异有统计学意义(P＜0.05,P＜0.01).四联方案治疗前患者GFR为(0.754±0.302) ml/s,治疗后1个月为(0.868±0.358)ml/s,治疗后6个月为(0.952±0.347) ml/s,治疗后12个月为(1.007±0.394) ml/s.治疗6个月和12个月后,患者GFR与治疗前相比较,差异有统计学意义(P＜0.05,P＜0.01).治疗1、6和12个月后,患者血胆固醇和甘油三酯与治疗前相比较,差异均无统计学意义(P＞0.05,P＞0.05).四联方案治疗前患者尿蛋白阳性率为9.4％,治疗后1个月为13.2％,治疗后6个月为22.6％,治疗后12个月为26.4％.治疗12个月后蛋白尿阳性率与治疗前相比较,差异有统计学意义(P＜0.05).结论 应用SRL+ CsA(或Tac)+ MMF+ Pred四联方案改善了CAN患者的血肌酐和GFR,但增加了患者蛋白尿的发生率.     

Chronic allograft nephropathy

Chronic allograft nephropathy (CAN) is the leading cause of renal allograft loss in paediatric renal transplant recipients. CAN is the result of immunological and nonimmunological injury, including acute rejection episodes, hypoperfusion, ischaemia reperfusion, calcineurin toxicity, infection and recurrent disease. The development of CAN is often insidious and may be preceded by subclinical rejection in a well-functioning allograft. Classification of CAN is histological using the Banff classification of renal allograft pathology with classic findings of interstitial fibrosis, tubular atrophy, glomerulosclerosis, fibrointimal hyperplasia and arteriolar hyalinosis. Although improvement in immunosuppression has led to greater 1-year graft survival rates, chronic graft loss remains relatively unchanged and opportunistic infectious complications remain a problem. Protocol biopsy monitoring is not current practice in paediatric transplantation for CAN monitoring but may have a place if new treatment options become available. Newer immunosuppression regimens, closer monitoring of the renal allograft and management of subclinical rejection may lead to reduced immune injury leading to CAN in the paediatric population but must be weighed against the risk of increased immunosuppression and calcineurin inhibitor nephrotoxicity.     

大鼠慢性移植肾肾病动物模型的制作经验总结

目的 总结制作稳定的大鼠慢性移植肾肾病(CAN)动物模型的经验.方法 以F344近交系大鼠为供者,取供者左肾作为供肾,原位低温灌注;以Lewis近交系大鼠为受者,行左侧原位肾移植,供肾动脉与受者腹主动脉端侧吻合,供肾静脉与受者肾静脉端端吻合,输尿管带膀胱瓣与受者膀胱吻合.术后用环孢素A灌胃10 d,剂量为10 mg·kg-1·d-1.每月采集受者血液和尿液,测定血肌酐及24 h尿蛋白,分别于术后2、4个月获取移植肾进行病理检查.结果 45只进行移植,手术成功率为85%,单次手术时间为(120±20)min.移植后1个月,大鼠即出现血肌酐、尿素氮及血胱抑素升高,24 h尿蛋白增加,与术前相比,各项指标均升高(P<0.05);术后2个月及4个月,除尿蛋白继续增加外,其余观察指标上升不明显.移植术后2个月,移植肾有轻度至中度的间质纤维化,淋巴细胞和浆细胞的浸润;4个月时,移植肾可见广泛的间质纤维增生,间质细胞大量浸润,肾小球基底膜增厚、硬化、闭塞,肾小管萎缩退化,符合CAN的病理改变.结论 通过充分的手术强化训练及改进,规范大鼠取、肾、移植术中、术后管理的每个细节,大鼠CAN模型的成功率及稳定性高.

Abstract：

Objective To summarize the experience of establishing the stable rat model of chronic allograft nephropathy. Methods We used Fisher rats as donors and Lewis rats as recipients.After the left kidney of the donor perfused in situ under hypothermic condition, the left renal vein,abdominal aorta and bladder flap of the donor was anastomosed with the left renal vein, renal artery and bladder of the recipient, respectively. The recipients were given cyclosporin oral solution 10 mg/kg every day by gavage for 10 days after transplantation. The blood and urine samples were collected 1 month, 2 months and 4 months after transplantation and renal function and total urine protein were examined. The pathological changes of the renal allograft were observed 2 and 4 months after transplantation. Results Forty-five rats received operation and achievement ratio was 85%. The renal transplantations were finished in 120 ± 20 min. The Scr, BUN, Cycs and total urine protein demonstrated a significant increase one month after transplantation. On the second and fourth month,with the exception of urine protein continued to increase, the other indicators did not change significantly. Two months after transplantation renal pathology demonstrated light to moderate interstitial fibrosis, infiltration of lymphocytes and plasma cells. At 4th month the renal allografts showed extensive interstitial fibrosis, a large number of infiltrating interstitial cells, thickening,hardening, occlusion of glomerular basement membrane, and renal tubular atrophy that were consistent with pathological changes of chronic allograft nephropathy. Conclusion Through adequate surgical training and improvement, and specification for rat nephrectomy, transplantation surgery,and postoperative management in every detail, the model with high success rate and stability can be achieved.     

钙调磷酸酶抑制剂转换为西罗莫司治疗慢性移植物肾病的疗效研究

探讨钙调磷酸酶抑制剂(CNI)转换为西罗莫司治疗慢性移植物肾病(chronic allograft nephropathy,CAN)的疗效及不良反应.方法 回顾性研究对象为2005年1月至2010年12月在西安交通大学医学院第一附属医院肾移植科随访的95例肾移植后并发CAN患者,术后均接受CNI为主的免疫抑制剂方案.所有患者均签署知情同意书,符合医学伦理学规定.患者确诊CAN后将CNI转换为西罗莫司.记录西罗莫司的维持剂量及血药浓度水平,了解转换治疗后血清肌酐(Scr)的变化,根据转换前Scr水平高低分为两组,Scr≥266 μmol/L为Scr高水平组(22例),Scr<266 μmol/L为Scr低水平组(73例);比较两组转换治疗后Scr变化幅度的差异;了解转换治疗的不良反应.结果 95例患者的随访时间6~48个月,西罗莫司的维持剂量为0.5~4 mg/d(中位数为1.5 mg/d),血药浓度为1.3~12 ng/ml(中位数为5.4 ng/ml).Scr低水平组转换治疗效果明显高于Scr高水平组(P<0.05).95例患者均未发生急性排斥反应.新发或蛋白尿加重32例(34%),新发或高脂血症加重25例(26%),1例患者发生肺部感染,经对症治疗后均治愈或缓解.结论 CNI类药物转换为西罗莫司治疗CAN是安全有效的,转换前Scr水平较低者的治疗效果优于转换前Scr水平较高者,转换后的主要并发症是蛋白尿和高脂血症.     

大豆异黄酮对大鼠慢性移植肾肾病的防治作用

目的通过对肾移植大鼠的饮食营养干预，观察大豆异黄酮对慢性移植肾肾病的防治作用。方法选择近交系雄性Fisher（F344）大鼠作为供者，雄性Lewis（Lew）大鼠作为受者，采用显微外科技术制作肾移植模型。将受者随机分为三组，分别给予高异黄酮大豆蛋白饲料（HIS组）、低异黄酮大豆蛋白饲料（LIS组）或酪蛋白饲料（CAS组）。移植前和移植后第4、12和24周时检测血压，并收集受者的血和尿样，检测尿蛋白和血肌酐含量。24周时处死大鼠获取移植肾，行组织学和免疫组织化学检查。结果在移植后4周时，HIS组受者的尾动脉收缩压、24h尿蛋白含量和血肌酐浓度即低于LIS组和CAS组，但差异无统计学意义（P〉0．05）；移植后12周和24周时，HIS组的受者尾动脉收缩压、24h尿蛋白含量和血肌酐浓度均较LIS组和CAS组显著降低（P〈0．05）；移植后24周时，HIS组移植肾组织的间质纤维化和炎症、血管硬化、肾小球硬化和肾小管萎缩等慢性病变均较LIS组和CAS组为轻（P〈0．05）；HIS组移植肾组织中转化生长因子-β1（TGF-β1）的表达和分泌均较LIS组和CAS组为少（P〈0．05）。结论大豆异黄酮对移植肾功能和结构有保护作用，可作为一种防治慢性移植肾肾病的新方法。     

慢性移植肾肾病模型中骨桥蛋白、α平滑肌肌动蛋白和E钙黏蛋白的表达

目的 观察骨桥蛋白(OPN)、α平滑肌肌动蛋白(α-SMA)、E钙黏蛋白在大鼠慢性移植肾肾病(CAN)模型移植肾中的表达及其表达的相关性.方法 以Fisher大鼠为供者,Lewis大鼠为受者,进行原位异体肾移植(CAN组);以供、受者均为Lewis大鼠的肾移植模型作为对照.术后12周处死受者,取血、尿样本检测移植肾功能,取移植肾进行HE染色和天狼星红染色,观察其组织形态学变化.采用免疫组织化学法和免疫印迹法观察移植肾组织OPN、α-SMA和E钙黏蛋白的表达.结果 CAN组大鼠移植肾组织形态学符合CAN的病理改变.免疫组化结果显示,与对照组相比较,CAN组肾小管上皮及肾间质中OPN和α-SMA的表达增强,而CAN组小管上皮E钙黏蛋白的表达明显下降.免疫印迹结果与免疫组化结果一致,CAN组移植肾组织中OPN和α-SMA的表达相对灰度值分别为85.74±2.29和88.79±4.44,对照组分别为14.25±0.71、11.21±0.56,两组间的差异有统计学意义(P＜0.05).CAN组E钙黏蛋白的相对灰度值为24.96±0.02,对照组为75.04±3.21,两组间的差异有统计学意义(P＜0.05).两组大鼠移植肾OPN的表达量与α-SMA的表达量呈正相关(r=0.746,P＜0.05),与E钙黏蛋白的表达量呈负相关(r=-0.526,P＜0.05).结论 CAN大鼠移植肾中OPN的表达增加,OPN可能参与了移植肾肾小管上皮细胞向间充质细胞转化的过程.

Abstract：

Objective To investigate the expression of OPN, α-SMA, E-cadherin and their correlation in the chronic allograft nephropathy (CAN) rat model, and to explore the possible role of OPN in CAN.Methods Orthotopic renal-transplantation using Fisher rats as donors and Lewis rats as recipients was done to establish CAN group, and Lewis to Lewis rats as control group. Rats in each group were sacrificed 12 weeks after the surgery. Blood and urine were collected for further test. Allograft samples were collected and sectioned for HE, Sirus-red staining, immunohistochemistry and Western blot.Results There were CAN morphological changes of the allograft in CAN group. As compared with control group, immunohistochemistry and Western blot revealed that the expression of OPN and α-SMA in CAN group was significantly increased, and that of E-Cadherin reduced. Its trend was correlated with the inflammatory response and the EMT of tubule epithelial cells.Conclusions OPN expression in rat CAN model is significantly up-regulated. OPN may play a role in CAN. OPN might affect the CAN by promoting EMT of tubule epithelial cells.     

Chronic renal allograft nephropathy

Chronic rejection/chronic allograft nephropathy is the most prevalent cause of renal graft loss after the first year post-transplant. Chronic rejection/chronic allograft nephropathy is characterized by a slow progressive deterioration of graft function, often in combination with proteinuria and hypertension. Both immunologic and non-immunologic factors play key roles in the pathogenesis of chronic allograft nephropathy. Acute rejection episodes are the most prevalent risk factor for chronic rejection. Many risk factors for chronic allograft nephropathy have been identified, such as delayed graft function, nephron-dosing mismatch, repeated acute rejection episodes, and pathologically severe rejection. However, the precise pathogenesis of chronic allograft nephropathy remains elusive. The differential diagnosis of immunologically mediated chronic rejection and chronic rejection caused by non-immunologic factors is usually not possible using clinical parameters. The histopathologic findings of chronic allograft nephropathy are progressive interstitial fibrosis and remodelling of the vascular wall, and these findings are nonspecific. However, typical chronic transplant glomerulopathy, which affects glomerular tufts, as well as the multilayering of the peritubular capillary basement membrane, are characteristic of immunologic chronic rejection. Furthermore, in long-surviving patient with an allograft treated with a potent immunosuppressive agent, a calcineurin inhibitor, two or more concomitant independent lesions often develop. Therefore, the term "chronic allograft nephropathy" may be clinically preferable to "chronic rejection" to describe the gradual decline in graft function months or years after transplantation, in the absence of a well defined mechanism of graft dysfunction. The most effective way to prevent chronic allograft nephropathy is to avoid any kind of graft damage via either immunologic or non-immunologic mechanisms. Received: April 1, 2000 / Accepted: May 2, 2000     

CD20阳性淋巴细胞在慢性移植肾肾病组织中浸润的意义

目的 探讨肾移植术后慢性移植物肾病(CAN)组织CD20阳性淋巴细胞浸润的临床意义及其机制.方法 选择肾移植术后2年内活检证实为CAN病例为研究对象,应用免疫组织化学方法检测补体C4d的沉积和CD20阳性淋巴细胞在移植肾组织的浸润,同时分析临床随访资料.结果 人选CAN病例44例,其中CD20阳性淋巴细胞浸润13例(29.5％),CD20阴性为31例(70.5％),移植肾组织不同病理分级者中CD20阳性者所占比例的差异无统计学意义(P＞0.05).44例中,12例(27.3％)出现管周毛细血管内皮细胞(PTC)补体C4d的线性沉积,CD20阳性和阴性者中补体C4d表达阳性率的差异无统计学意义(P＞0.05).确诊为CAN时移植肾组织CD20为阴性和阳性者的肾功能分别为( 140.8±22.0)μmol/L和(183.5±25.5) μmol/L(P＜0.01),1年后分别为(165.6±37.6)μmol/L和(242.2±59.1 )μmol/L(P＜0.01).结论 CD20阳性淋巴细胞在移植肾组织的浸润与移植物的预后相关,其机制可能不是通过慢性体液免疫反应.     

肾移植术后一年体质量指数对慢性移植物肾病的影响

目的 研究肾移植患者术后1年体质量指数(BMI)对慢性移植物肾病(CAN)的影响.方法 肾移植术受者564例,依据BMI分3组:①I组:18.5≤BMI≤25(正常);②Ⅱ组:25＜BMI≤30(超重);③Ⅲ组,BMI＞30(肥胖).比较各组术后高血压、糖尿病、CAN等发生情况.结果 各组术后1年的BMI均较术前增加,其中Ⅱ、Ⅲ组与术前比较差异有统计学意义(P值分别＜0.05和0.01).3组CAN发生率分别为34.9%(128/367)、38.4%(48/125)、43.1%(31/72),术后1年随着BMI的升高而增加,Ⅲ组与Ⅰ组比较差异有统计学意义(P＜0.05);高血压、糖尿病和高脂血症的发病率随着BMI升高而增加,Ⅲ组与Ⅰ组高血压、糖尿病和高脂血症的发生率分别为30.6%(22/72)和21.0%(77/367)、26.4%(19/72)和15.8%(58/367)、29.2%(21/72)和18.1%(66/367),2组比较差异有统计学意义(P＜0.05);急性排斥反应发生率:Ⅰ组26.4%(97/367),Ⅱ组25.6%(32/125),Ⅲ组22.2%(16/72),3组之间急性排斥反应发生率比较差异无统计学意义(P＞0.05).结论 肾移植患者术后1年BMI和CAN的发生密切相关,通过饮食控制、适当体育锻炼、免疫抑制剂减量等措施可以控制移植后BMI,进而最大限度降低CAN的发生.     

Impact of recurrent disease and chronic allograft nephropathy on the long‐term allograft outcome in patients with IgA nephropathy

Although recurrent IgA nephropathy (IgAN) may lead to graft dysfunction after transplantation, donation from living related donor (LRD), with whom the risk of recurrence may be higher, is not a contraindication. Herein, we evaluated the natural history of allograft in recipients with IgAN and the risk factors influencing long‐term allograft outcome. Recurrence rate and graft survival were assessed retrospectively in 221 IgAN patients, including transplants from 139 LRDs (62.9%). Ten‐year cumulative rate for recurrent IgAN was 30.8%. The operation at younger age and donation from LRD were significant for the recurrence by multivariate analysis. Ten‐year graft survival was affected by recurrent IgAN (61.0% in recurrent IgAN group vs. 85.1% in nonrecurrent, P < 0.01). However, transplants from LRDs did not show poor graft survival when compared with those from other types of donors. In transplants from LRDs, the incidence of chronic allograft nephropathy (CAN) was lower than those in grafts from deceased donors (10.8% vs. 19.5%, P < 0.05). When CAN was considered in addition to recurrence, the variance of graft survival was affected significantly by the development of CAN than by the recurrence. These results suggest that the detection and adequate management of CAN could improve graft outcome in transplant recipients with IgAN.     

磷酸化肌球蛋白轻链在大鼠慢性移植肾肾病早期病变中的作用及其机制

目的 探讨磷酸化肌球蛋白轻链(pMLC)在慢性移植肾肾病(CAN)中的作用与机制.方法 依照标准的CAN大鼠模型进行左肾原位移植,受者为LEW大鼠,供者为F344大鼠,另取雄性F344大鼠和LEW大鼠仅行单肾切除术,分别作为对照.分别于术后4、8及12周时,收集各组大鼠的24 h尿量,并检测其尿肌酐水平,计算肌酐清除率.然后取各组大鼠血液标本,测定血清肌酐水平.采用Banff分级标准评定各组肾小球肾病、肾小管萎缩、间质纤维化及血管内膜增厚程度.采用免疫组织化学法和采用蛋白质印迹法检测肾组织中磷酸化MLC(pMLC)和整合素连接激酶(ILK)的表达部位及表达水平.结果 移植组大鼠术后4周时肾间质可见单个核细胞浸润,12周时可见血管平滑肌细胞的移行与增殖.移植组大鼠各时相肾组织pMLC和ILK表达水平显著高于Lewis对照组及F344对照组,且随着移植时间的延长有逐渐增高趋势.大鼠移植肾组织中pMLC表达水平与24 h尿蛋白定量、血清肌酐水平、肾间质单个核细胞浸润、肾小动脉血管平滑肌细胞数量、Banff评分等呈显著正相关,相关系数(r)分别为0.273(P＜0.05)、0.434(P＜0.01)、0.525(P＜0.01)、0.676(P＜0.01)、0.570(P＜0.01),在移植后4周时,pMLC表达水平与肾小管间质ILK表达水平呈显著正相关,r=0.778(P＜0.01).结论 pMLC在慢性移植肾病早期病理变化中发挥重要作用,移植肾肾小管间质及肾小动脉中pMLC表达上调与ILK的作用机制相关.

Abstract：

Objective To investigate the role and mechanism of phosphate myosin light chain (pMLC) in the rat kidney of chronic allograft nephropathy (CAN) model. Methods The left donor kidneys from Fisher (F344) rats were orthotopically transplanted into Lewis recipients. Meanwhile, the F344 rats and LEW rats with resection of the right kidney served as control groups. Animals were harvested respectively at the 4th, 8th and 12th week after transplantation. The creatinine clearance rate (CCr) was calculated by urine creatinine of 24-h urine. Blood samples were collected from rats for determination of serum creatinine. The expression of pMLC was detected by using Western blotting and immunohistochernistry, and that of integrin-linked kinase (ILK) by using immunohistochemistry. Results Mononuclear cells infiltration of allografts was markedly aggravated as compared to the controls. Allografts got severe interstitial fibrosis and tubular atrophy at 12th week after transplantation. The expression of pMILC and ILK was up-regulated in the kidney of CAN rats after transplantation, and increased more significantly as the time went on. The expression of pMILC was significantly correlated with 24-h urine protein excretion (r= 0. 273, P＜0. 05), serum creatinine levels (r = 0. 434, P＜0. 01 ), the number of tubulointerstitial infiltrated mononuclear cells (r = 0. 525, P＜0. 01 ), the number of smooth muscle cells (SMC) in vascular wall (r= 0. 676, P＜0. 01 ) and the extent of interstitial fibrosis (r= 0. 570, P＜0. 01 ).There was a significantly positive correlation between ILK and pMLC in CAN rats at the 4th week after transplantation (r= 0. 778, P＜0. 01 ). Conclusion pMLC might play an key role in CAN, and the over-expression of ILK might be involve in the pathogenesis of CAN.     

抗可诱导共刺激分子抗体对大鼠慢性移植肾肾病的影响

目的 探讨应用抗可诱导共刺激分子(ICOS)抗体阻断ICOS-BTRP-1共刺激通路对大鼠慢性移植肾肾病(CAN)的影响及其可能机制.方法 实验分为3组:(1)同系对照组,供、受者均为Wistar大鼠,进行肾移植;(2)同种对照组,以SD大鼠为供者,Wistar大鼠为受者进行肾移植,术后灌胃给予环孢素A(CsA),用10 d;(3)实验组,在同种对照组的基础上,于使用CsA后经腹腔注射抗ICOS单克隆抗体,2 mg/kg,2次/周,共用3个月.各组分别于术后4、8和12周,检测受者血清肌酐;观察移植肾的病理学变化;用免疫组织化学法检测移植肾和受者脾脏中ICOS的表达;检测移植肾组织中ICOS mRNA的表达.另取存活6个月的实验组和同系对照组大鼠,检测其外周血中CD4+CD25+T淋巴细胞的比例.结果 同系对照组术后各个时间点的血清肌酐变化不大;同种对照组血清肌酐明显升高,12周时达(310±18)μmol/L;实验组血清肌酐也呈上升趋势,但上升幅度明显低于同种对照组,至12周时为(122±13)μmol/L.术后12周时,同种对照组移植肾肾小球硬化率和Banff评分(总分)分别为(54.75±3.06)%和8.28±1.41,实验组为(15.05±1.64)%和6.13±1.00,两组比较,差异有统计学意义(P＜0.01).同系对照组受者脾脏边缘区可见ICOS表达,白髓区少见ICOS表达,该组移植肾内未见ICOS明显表达;在同种对照组,移植后各时间点移植肾和受者脾脏中都可见ICOS明显表达;实验组移植肾和受者脾脏内ICOS的表达明显下降,且主要表达于脾脏的白髓区,边缘区很少表达.术后4、8和12周时,实验组各个时间点ICOS mRNA的表达明显低于同种对照组.实验组存活＞6个月者外周血中CD4+CD25+T淋巴细胞的比例平均为13.5%,同系对照组平均为9.1%.结论 应用抗ICOS抗体阻断ICOS-B7RP-1共刺激通路可在一定程度上抑制CAN的进展,其机制可能与移植肾组织ICOS的表达受到抑制及ICOS在受者脾脏内的重新分布有关,其中也可能有CD4+CD25+调节性T淋巴细胞的参与.