磁共振成像监测大鼠肝脏内经超顺磁铁氧化物标记的胰岛移植物

目的 探讨磁共振成像(MRI)监测胰岛移植物的可行性.方法 在体外利用超顺磁铁氧化物(SPIO)标记大鼠胰岛,然后移植至用链佐星诱导的糖尿病大鼠肝脏内,同系移植标记组供、受者均为Wistar大鼠,同种移植标记组供者为Lewis大鼠,受者为Wistar大鼠.并设同系移植对照组(供、受者均为Wistar大鼠)和同种移植对照组(供者为Lewis大鼠,受者为Wistar大鼠),胰岛移植物未经SPIO标记.术后定期利用MRI监测肝内胰岛移植物,监测受者的血糖,并抽取动物,对其肝脏进行病理检查.结果 只有SPIO标记的胰岛移植物能被MRI检测到.经MRI检测,同系移植标记组术后第1、2、3周胰岛移植物的相对数量分别为(89.6±2.2)%、(87.5±14.4)%和(74.5±19.5)%,同种移植标记组术后第1、2、3周的相对数量分别为(43.2±17.2)%,(36.5±13.0)%和(26.5±17.4)%,组间相同时间点两两比较,差异有统计学意义(P<0.05).同系移植标记组血糖始终维持在正常水平,肝脏中能检测到胰岛素免疫组化和普鲁士蓝染色双阳性细胞;而同种移植标记组移植1周后的血糖水平超过16.8 mmol/L,肝脏中无法找到形态完整的胰岛.结论 MRI监测结果与血糖监测和病理检查结果一致,但它可直观、无创、连续地监测胰岛移植物在体内分布和存活情况.     

单核细胞趋化因子-1和RANTES在慢性移植肾肾病大鼠肾组织中的表达及意义

目的　探讨慢性移植肾肾病大鼠模型肾组织中单核细胞趋化因子1(MCP 1)和RANTES的表达及意义。方法　以F344大鼠为供者、Lewis大鼠为受者建立慢性移植肾肾病(CAN)大鼠模型,以切除单侧肾脏的F344大鼠和Lewis大鼠为对照。术后12周,测定各组大鼠的肾功能以及肾组织中MCP 1和RANTES的表达,并观察同期肾组织学改变。结果　与单纯切肾的F344大鼠比较,CAN大鼠的血清肌酐水平明显升高(P<0.05),每100 g体重肌酐清除率明显降低(P<0.01);CAN大鼠肾组织的Banff评分明显高于单纯切肾的F344大鼠和Lewis大鼠(P<0.01); CAN大鼠肾组织中MCP 1 和RANTES的表达明显高于单纯切肾的F344大鼠(P<0.05,P<0.01);CAN大鼠移植肾组织学改变与肾组织中MCP 1和RANTES的表达呈正相关关系(r=0.5543,P<0.05;r=0.6259,P<0.05)。结论肾组织中MCP 1和RANTES的表达升高可能与慢性移植肾肾病的发生有关。     

以吗替麦考酚酯为基础的免疫抑制策略(续)

六、术前应用环孢素A(CsA)+吗替麦考酚酯(MMF)诱导可获更佳移植肾功能 Soliman等将80例肾移植受者平均分为两组,组1术后接受标准剂量的CsA+MMF+标准剂量糖皮质激素治疗,组2术前48 h接受CsA+MMF诱导,术后接受低剂量CsA+MMF+低剂量糖皮质激素治疗,以探索术前CsA+MMF诱导治疗是否可降低术后CsA使用剂量及毒性,并改善移植肾功能.     

肝硬化大鼠原位肝移植模型的制作及术后排斥反应的观察

目的 制备肝硬化大鼠的原位肝移植模型,观察术后排斥反应发生情况,为进行其它研究创建一个平台.方法 以皮下注射CCl4联合饮用苯巴比妥钠和乙醇溶液的方法制备大鼠肝硬化模型,应用改良的"二袖套"法建立大鼠原位肝移植模型,同系移植者的供、受者均为SD大鼠(SD实验组),以接受肝移植的正常SD大鼠为对照(SD对照组);同种移植者的供者为Lewis大鼠,受者为BN大鼠(BN实验组),以接受肝移植的正常BN大鼠为对照(BN对照组).术后观察受者的存活情况以及移植肝的组织学变化.结果 肝硬化大鼠门静脉压力为(182.0±10.7)mm H2O,显著高于正常大鼠的(70.8±5.5)mm H2O(P＜0.01),移植后7 d降至(82.7±10.7)mm H2O.同种移植组术后5～12 d,移植肝组织中均可见中、重度急性排斥反应病理改变.同系移植者存活时间中位数均＞100 d;同种移植者中,BN对照组和BN实验组受者肝移植后存活时间中位数均为10 d.结论 以Lewis大鼠为供者、肝硬化BN大鼠为受者制备的肝移植模型术后排斥反应的发生率较高,可作为肝移植后排斥反应相关研究的平台.     

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.     

在移植肾功能稳定的受者中主动撤除环孢素A的临床研究

目的 研究在移植肾功能稳定的受者中主动撤除环孢素A(CSA)对急性排斥反应发生率及肾功能的影响.方法 选择35例肾功能稳定的肾移植受者,其中尸体肾移植23例,亲属活体肾移植12例.除2例为再次肾移植外,其余均为初次肾移植.分别在肾移植术后6个月～6年时停用CsA,平均为术后(13.3±9.1)个月.撤除CsA后免疫抑制方案为:霉酚酸酯(MMF)+西罗莫司(SRL)+泼尼松(Pred).撤除CsA前有9例做了移植肾穿刺活检,8例测定了抗HLA抗体.结果 对35例受者随访6个月～4.5年,平均14.8个月.撤除CsA前、后血肌酐平均值分别为(88.1±15.5)μmol/L和(92.3±23.7)/μmol/L(P0.05).撤除CsA后,有2例经活检证实发生急性排斥反应,治疗后均逆转;CsA所致的毒副作用,如牙龈增生、糖耐量异常和多毛症等明显改善.9例移植肾活检中,有3例肾功能正常的受者已出现轻度慢性移植肾肾病表现.抗HLA抗体检测中,7例阴性者在撤除CsA前、后肾功能无明显变化.1例抗HLA抗体呈强阳性者在撤除CsA后进展为慢性移植肾肾病,恢复血液透析.结论 对移植肾功能稳定的受者在移植6个月后撤除CsA,转换为"霉酚酸酯+西罗莫司+泼尼松"的免疫抑制方案是安全的,不增加急性排斥反应风险;撤除CsA有利于消除一些与其相关的毒副作用;对抗HLA抗体呈强阳性者.撤除CsA后很难改变肾功能的进展.     

比较他克莫司和霉酚酸酯对大鼠慢性移植肾肾病的影响

目的 比较他克莫司(FK506)和霉酚酸酯(MMF)对慢性移植肾肾病(CAN)大鼠移植肾组织中趋化因子FKN以及受体CX3CR1表达的影响.方法 以 SD大鼠为供者,Wistar大鼠为受者,肾移植后制作慢性移植肾肾病模型.实验分为4组,每组均有24只.假手术组:只游离左肾血管和结扎右肾;对照组:受者为CAN对照;FK506组:受者为CAN,使用FK506 0.15 mg·kg-1·d-1;MMF组:受者为cAN,使用MMF 20 mg·kg-1·d-1.除假手术组外,每组受者术后均先使用环孢素A(CsA)10 mg·kg-1·d-1×10 d以渡过肾移植急性排斥期,然后予相应干预措施.分别于术后4、8及12周时处死受者,每组各时点处死的受者均为8只.光镜下检测移植肾组织的病理改变;采用免疫组织化学染色和实时荧光定量聚合酶链反应(PCR)检测移植肾组织中FKN和CX3CR1蛋白及其mRNA的表达.结果 对照组术后4周时移植肾问质小血管内膜开始增厚,肾小球开始出现硬化表现.8周时上述变化更为显著,12周时移植肾50%以上的肾小球出现硬化以及肾小管萎缩、间质明显纤维化等改变.FK506组出现CAN病理改变的时间较对照组早,且病变程度相对较重.MMF组出现明显CAN病理改变的时间较对照组晚,且病变程度相对较轻.FKN和CX3CR1主要表达于肾小管上皮细胞的胞膜和肾小管间质,部分见于间质血管,偶见于.肾小球壁层细胞.术后各时点的移植肾标本中,对照组FKN和CX3CR1的mRNA和蛋白表达均高于假手术组;FK506组均高于对照组;而MMF组均低于对照组.结论 FKN和CX3CR1在肾小管间质中的表达可能与CAN中肾小管损伤、间质纤维化等病理改变密切相关.MMF可能通过下调FKN和CX3CR1的表达对CAN的进展具有延缓作用;而FK506可能通过上调FKN和C2X3CR1的表达来促进CAN病变的发展.     

整合素连接激酶在大鼠慢性移植肾肾病中的作用与机制

目的探讨整合素连接激酶(ILK)在慢性移植肾肾病(CAN)中的作用与机制。方法实验组肾移植受者为雄性Lewis大鼠40只,供者为雄性F344大鼠40只,依照标准的慢性移植肾肾病大鼠模型要求行左肾原位移植。对照组分别为行单纯右肾切除的Lewis大鼠及F344大鼠各25只。于术后4、8、12、16及24周时分批处死大鼠,同时做肾功能与组织学检测,免疫组织化学与蛋白印迹法测定肾组织中ILK的表达,逆转录聚合酶链(RT-PCR)法检测ILK mRNA的表达,免疫组织化学方法检测基质金属蛋白酶9(MMP-9)的表达。结果CAN大鼠移植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,24周时可见轻度肾间质纤维化、血管硬化及管腔狭窄。CAN大鼠肾组织中ILK及ILK mRNA表达水平显著增高,且随着移植时间的延长有逐渐增高趋势。CAN大鼠肾移植术后8周前肾小管间质及肾小动脉MMP-9表达水平均显著高于同时段LEW对照组及F344对照组,16周后显著降低。Spearman等级相关分析结果显示:CAN大鼠肾组织中ILK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程度、肾小动脉平滑肌细胞数量、肾间质纤维化程度等呈显著正相关,与8周前MMP-9表达水平呈正相关,12周后无显著相关性。结论ILK在慢性移植肾肾病病理变化中发挥重要作用,移植早期肾小管间质及肾小动脉中MMP-9表达上调与ILK的作用机制有关。     

磷酸化糖原合成酶激酶-3β在大鼠移植肾早期病理改变中的作用

目的 探讨糖原合成酶激酶-3β(GSK-3β)在大鼠移植肾早期病理改变中的作用.方法 以F344大鼠为供者,Lewis大鼠为受者,依照标准的慢性移植肾肾病(CAN)模型要求行左肾原位移植,制作CAN模型(移植组).术后7d切除受者的右肾.以切除一侧肾脏的雄性F344大鼠和Lewis 大鼠为对照(F344对照组和LEW对照组).分别于术后4、8、12、16及24周时收集24 h尿液,采集血液,测定24 h尿蛋白和血肌酐,取移植肾组织,观察组织学改变,并用免疫组化法检测肾组织中磷酸化GSK-3β表达.结果 移植组术后早期(4、8和12周)移植肾病理改变主要表现为单个核细胞浸润、血管平滑肌细胞(SMC)的移行增殖,在后期(16和24周)尿蛋白排泄率显著增高,移植肾病理改变表现为肾间质单个核细胞浸润明显增加及严重的肾间质纤维化、肾小管萎缩.移植组术后各时间点移植肾组织中磷酸化GSK-3β及其mRNA表达水平均显著低于LEW对照组和F344对照组相同时点的表达水平(P＜0.05),并随着移植时间的延长进一步降低.磷酸化GSK-3β表达水平与早期肾间质单个核细胞浸润程度、SMC移行增殖及后期肾间质纤维化、肾小管萎缩、血管硬化程度呈显著负相关.结论 磷酸化GSK-3β表达下调在大鼠移植肾早期的肾间质单个核细胞浸润、SMC移行增殖及后期的肾间质纤维化、肾小管萎缩、肾血管硬化病变的发生中均起重要作用.     

川芎嗪联合丹参延缓肾移植大鼠慢性移植肾肾病进程的作用

目的 研究川芎嗪(TMP)联合丹参延缓肾移植大鼠慢性移植肾肾病进程的作用及机制.方法 以Fisher 344大鼠和Lewis大鼠分别作为肾移植的供、受者进行原位肾移植,并建立CAN模型.按随机数字表法将受鼠分为5组:环孢素A(CsA)组(A组),TMP+ CsA组(B组)、丹参+ CsA组(C组)、TMP+丹参+CsA组(D组)及空白对照组(E组,术使用任何药物).分别于术后2、4、6、8和12周,处死每组5只受鼠,取移植肾进行移植肾组织病理学变化,采用免疫组织化学法检测移植肾组织转化生长因子β1(TGF-β1)的表达,采用荧光定量聚合酶链反应法检测移植肾组织TGF-β1 mRNA的表达.结果　术后空白对照组受鼠的存活时间均未超过2周.A组于术后4周时最早出现CAN病理改变,B组和C组出现CAN病理改变的时间较A组晚,D组出现CAN病理改变的时间最晚,且病理改变程度最轻.术后各组Banff评分均呈现明显的上升趋势,相同时间点,A组明显高于其他3组(P＜0.05和P＜0.0 1),D组明显低于与B组和C组(P＜0.05),而B组与C组间无显著差异(P＞0.05).随着术后时间的推移,各组TGFβ1表达强度呈逐渐增加的趋势,相同时间点,A组TGF-β1表达强度最高,与其他3组比较,差异均有统计学意义(P＜0.05和P＜0.01),D组明显低于B组和C组(P＜0.05),B组与C组间无明显差异(P＞0.05).各组TGF-β1 mRNA表达的变化趋势及组间差异与TGF-β表达强度的情况相一致.结论 TMP或丹参均具有通过下调TGF-β1 的表达延缓肾移植大鼠CAN进程的作用,当两者联合应用时作用更为明显.     

非清髓性方案在诱导大鼠后肢移植免疫耐受中的应用

目的 探讨基于淋巴细胞毒性相关抗原4-抗体重组腺病毒(AdCTLA4-Ig)的非清髓性方案在造血干细胞嵌合体诱导复合组织异体移植免疫耐受中的作用.方法 以近交系Brown Norway(RT1n)大鼠为供体,Lewis(RT11)大鼠为受体.以后肢移植当天记为day 0.实验分4组,A组:受体直接给予同种异体后肢移植,移植前不进行非清髓件预处理,移植后连续100 d,每天仅给予低剂量环胞素A(CsA),8 mg/kg腹腔注射.B组:受体先给予非清髓性预处理,移植前第33天至移植后第100天,每日用免疫抑制剂三联方案腹腔注射雷帕霉素(RAPA,0.2 mg/kg)+麦考(MMF,20 mg/kg)+甲泼尼龙(MP,10 mg/kg),在移植当日及移植前及移植后第30天分3次尾静脉注射AdCTLA4-Ig(5×109 PFU/d),后肢移植前30 d接受单次3 Gy(照射率0.5 Gy/min)低强度全身照射,不予骨髓移植(BMT).C组:受体预处理方案同B组,移植前30 d,在低强度全身照射后4 h内给予单次尾静脉注射供体骨髓细胞(100×106 cells).D组:受体预处理方案及BMT方法同C组,但大鼠后肢移植供体为第三方动物WF大鼠.在后肢移植后第100天开始,B、C及D组均停止免疫抑制剂三联方案,每日仅给予低剂量CsA(8 mg/kg),连续100 d,直至大鼠后肢移植物发生排异反应而坏死.通过外周血嵌合率检测、移植物抗宿主病检测、后肢移植物存活情况观察、移植物组织病理学检查与评价及混合淋巴细胞反应对免疫耐受状态进行分析评价.结果 C组外周血嵌合率移植当口为(38.8±10.6)%,并长期保持稳定,移植后第300天为(29.3±11.9)%,均未发生移植物抗宿主病,停止免疫抑制剂三联方案后移植物存活>200 d,A、B、D组均发生免疫排异,后肢移植物分别存活(8±2)、(18±3)及(20±2)d,与C组相比,差异有统计学意义(P<0.01).C组移植物病理学检查显示无毛囊炎及血管周围炎等慢性免疫排异现象,混合淋巴细胞反应显示为供体特异性免疫耐受状态.结论 基于AdCTLA4-Ig的非清髓性BMT方案可以诱导长期稳定的造血干细胞嵌合体状态,并可以诱导受体对大鼠后肢移植物的供体特异性部分性免疫耐受.     

C4d deposition is correlated with the level of antivimentin antibody in rat kidneys undergoing chronic allograft nephropathy

Aims

Antivimentin antibody is often produced as an autoantibody after transplantation. C4d deposition, a marker of humoral immunity during transplantation, is believed to reflect alloantibodies. This study investigated the relationship between C4d deposition and humoral immunity to vimentin among rat kidneys undergoing chronic allograft nephropathy (CAN).

Methods

Fisher 344 rat renal grafts were orthotopically transplanted into Lewis rats following the procedure of Kamada with our modification. All recipients were administered cyclosporine (CsA) (10 mg/kg⁻¹ · d⁻¹ × 10 d) before being divided into 3 groups of oral treatments: (1) vehicle, (2) CsA (6 mg/kg⁻¹ · d⁻¹), and (3) mycophenolate mofetil (MMF; 20 mg/kg⁻¹ · d⁻¹). At 4, 8 and 12 weeks after transplantation, the rats were killed, the renal allografts harvested, and the sera collected. Serum creatinine (SCr) was measured and pathologic changes assessed according to the Banff 97 criteria. The antivimentin antibody was quantified by enzyme-linked immunosorbent assay. The deposition of C4d detected by immunofluorescence was analyzed by integrated optical density (IOD).

Results

Antivimentin antibody was observed in sera of all transplanted rats. The level of antivimentin antibody (IgGΔOD) increased gradually during the development of CAN from 4 weeks. Simultaneously, C4d deposition in peritubular capillaries also progressively strengthened. There was a strong positive correlation between the content of antivimentin antibody and C4d deposition (r = 0.892; P = .000). MMF simultaneously decreased antivimentin antibody formation and C4d deposition. In contrast, CsA had no significant effect.

Conclusions

We demonstrated the production of antivimentin antibodies and the deposition of C4d during the development of CAN. There was a positive correlation between them. Whether humoral immunity to vimentin contributes to C4d deposition is not clear and further studies are needed to elucidate this issue.     

Detection of Citrate Synthase Autoantibodies in Rats with Chronic Allograft Nephropathy

Citrate synthase (CS) is the one of the key enzymes in the citric acid cycle and an important mitochondrial autoantigen. The autoimmune responses against CS have not been studied in chronic allograft nephropathy (CAN). This study investigated the role of specific CS autoantibodies in rats bearing renal allografts affected with CAN.

Methods

Fisher344 rat renal grafts were orthotopically transplanted into Lewis rats following the procedure of Kamada with our modification. Lewis-to-Lewis and Fisher344-to-Fisher344 kidney transplantations were also performed as autologous control groups (each n = 9). All the allograft recipients given cyclosporine (10 mg/kg⁻¹d⁻¹ × 10 d) were divided into four groups (each n = 9): (1) vehicle: normal saline orally; (2) cyclosporine: 6 mg/kg⁻¹d⁻¹; (3)FK506: 0.15 mg/kg⁻¹d⁻¹; (4) mycophenolate mofetil (MMF): 20 mg/ kg⁻¹d⁻¹. At 4, 8, and 12 weeks posttransplantation, the animals were sacrificed to harvest sera and renal allografts. The serum creatinine (SCr) was measured and pathological changes assessed according to Banff 97 criteria. IgM and IgG isotypes of CS antibodies were detected in all recipient sera by enzyme linked immunosorbent assays.

Results

Both IgM and IgG isotype CS autoantibodies were observed in the sera of all the recipients before and after transplantation, but the levels of IgM CS autoantibody were obviously higher than IgG isotype in all the blood samples. It was stable not only in autologous but also in allograft groups. In both autologous groups, the SCr and IgM and IgG isotype CS autoantibodies showed no obvious change before and after transplantation, and no typical CAN occurred. The values of IgG isotype of CS autoantibody (ΔOD) at 4, 8 and 12 weeks were stable. At 4 weeks, the values of SCr, Banff score, and IgG isotype CS autoantibody (ΔOD) were not significantly different (P > .05) among the allograft groups. At 8 and 12 weeks, with progression of CAN in vehicle, cyclosporine and FK506 groups' values of SCr, Banff score, and IgG (ΔOD) also increased dramatically (P = .005) in all three groups when compared with the baseline and 4 week values, but the differences among the three groups were not significant (P > .05). At 8 and 12 weeks, the MMF group suffered mild-to-moderate CAN, but the values of SCr and Banff score were significantly lower than those in the other three groups. MMF significantly inhibited the formation of IgG (ΔOD) when compared with the other three groups (P = .02).

Conclusion

This study suggested that the IgG isotype of CS autoantibody contributes to CAN after kidney transplantation. The IgM isotype is physiological. MMF significantly inhibited the formation of IgG isotype CS autoantibody, which may be related to its effects to alleviate CAN.     

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.     

灵长类动物预致敏后肾移植加速排斥反应模型的建立

目的 建立灵长类动物预致敏后肾移植加速排斥反应模型.方法 取血型相容的正常猕猴配对,预先将供者腹部全层皮肤移植到受者背部,使受者预致敏.2周后再将同一供者的左侧肾脏移植到受者腹腔内,间时切除受者自体双肾,术后予以环孢素A、霉酚酸酯和泼尼松治疗(致敏用药组),不用免疫抑制剂者为对照(致敏对照组),以未致敏的肾移植作为对照组.术后观察受者血肌酐变化、移植物存活时间及病理特点.结果 对照组的4只移植肾存活时间分别为9、18、8、7 d;致敏对照组的3只移植肾存活时间分别为3、3、4 d;致敏用药组的3只移植肾存活时间分别为2、3、4 d.移植皮肤于术后10 d出现排斥反应,至术后14 d被完全排斥.对照组于肾移植1周以后才发牛排斥反应,而致敏者均在肾移植后3 d左右发生较严重的排斥反应.结论 受者被供者皮肤预致敏后再行肾移植,可以加速移植物的排斥,且不能被环孢素A、霉酚酸酯及泼尼松所组成的三联免疫抑制方案逆转.     

Early short-term platelet-derived growth factor inhibition prevents the development of chronic allograft nephropathy in experimental rat kidney transplantation

Chronic allograft nephropathy (CAN) remains the primary reason for late allograft loss in kidney transplantation. Platelet-derived growth factor (PDGF) is a major mitogen mediating mesenchymal cell proliferation in CAN. When administered continuously the PDGF receptor tyrosine kinase inhibitor imatinib prevents the development of CAN and restores kidney function in experimental kidney transplantation. Herein we investigated whether early short-term imatinib treatment prevented CAN. Kidney transplantations were performed from DA to WF rats and syngenic controls were done between DA rats. Allograft recipients were immunosuppressed with cyclosporine (CsA; 1.5 mg/kg/d sc). One group of allografts was also treated with imatinib (10 mg/kg/d po). Serum creatinine levels were measured once a week. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry (PDGF-AA, -BB, PDGFR-alpha, -beta). Histological changes were scored according to the Chronic Allograft Damage Index (CADI). Among syngenic grafts, no signs of CAN were observed, namely, CADI 0.3 +/- 0.2 (mean +/- SEM). Control allografts showed moderate to intense chronic changes, CADI 6.5 +/- 1.3. Early short-term imatinib treatment significantly prevented the development of CAN compared with control allografts. Only a few histological changes were seen, namely, CADI 3.3 +/- 1.4. Compared with control allografts PDGF ligand and receptor induction was significantly inhibited by imatinib to nearly the same level as in syngenic grafts. Creatinine values of imatinib-treated allografts were also lower than control allografts. Our results demonstrated that early short-term imatinib treatment significantly prevented CAN. This indicated that early PDGF induction has an important role in the pathogenesis of CAN.     

The effects of different immunosuppressants on chronic allograft nephropathy by affecting the transforming growth factor-beta and Smads signal pathways

OBJECTIVE: This study investigated the effects of various immunosuppressants on chronic allograft nephropathy (CAN) by affecting transforming growth factor-beta (TGF-beta) and Smads signal pathway. METHODS: Vascular smooth muscle cells (VMSC) from rat aorta were incubated for 6 or 12 hours with various immunosuppressants. Cyclosporine (CsA) (3 microg/mL), FK506 (1 microg/mL), mycophenolate mofetil (MMF) (0.3 microg/mL), rapamycine (Rapa) (10 microg/mL), CsA (1 microg/mL/MMF 0.3 microg/mL). We used the Sprague-Dawley Wistar rat accelerated kidney sclerosis model. Before transplantation, the kidney was preserved 1 hour in 0 degrees C to 4 degrees C heparin sodium chloride solution to reinforce the cold ischemia injury. The rats were divided into eight groups (each group n = 8): group A, pseudo-OP; group B, isotransplantation; group C, CsA 6 mg/kg . d; group D, FK506 0.15 mg/kg . d; group E, MMF 20 mg/kg . d; group F, Rapa 0.8 mg/kg. d; group G, CsA 3 mg/kg . d + MMF 20 mg/kg . d. The serum creatinine levels and pathological changes, according to the Banff scheme, were observed at 2, 4, 6, 8 and 12 weeks posttransplantation. Immunohistochemistry and quantitative fluorescence polymerase chain reactions were used to end localize and quantitate the expression of TGF-beta1 and Smad 2, 3, 7 in VMSC and in the transplanted kidney. RESULTS: CsA and FK506 stimulated gene expression and protein production of TGF-beta1, smad2, and smad3, but inhibited expression of smad7 both in VSMC and in the transplanted kidney. In contrast, MMF and Rapa down-regulated gene expression and protein production of TGF-beta1, smad2, 3 while up-regulating expression of smad7. There was no significant difference between the CsA group and the FK506 group, as well as the MMF group and the Rapa group. The group treated with CsA + MMF was similar to the MMF and the Rapa groups. CONCLUSION: Our study suggested that various immunosuppressants affected differentially TGF-beta1 and Smads signal pathways in rat VSMC and kidney grafts. CsA and FK506 can cause CAN, owing to up-regulated expression of smad2 and smad3, and down-regulation of smad7 expression. MMF and Rapa can prevent the CAN progression, because of down-regulation of the expression of smad2 and smad3, with increased smad7 production.