The use of FK506 and RS61443 for reversal of small-bowel rejection

Successful clinical small-bowel transplantation is still difficult to achieve [3, 6]. Two features render the small intestine unique among vascularised solid organ grafts. First, the bowel contains a large amount of lymphoid tissue within the Peyer's patches, mesenteric lymph nodes, and intraepithelial lymphocytes, which are thought to mediate graft-versus-host disease and provide a major stimulus for the recipient's immune system [10]. Unfortunately, mere surgical reduction of these tissues, by using segmental allografts, does not furnish any immunological advantage [12]. Second, the small bowel lacks specific serum markers such as blood urea nitrogen (BUN) in the kidney or bilirubin in liver transplantation. Clinical signs such as fever, pain, or tenderness of the abdomen may indicate an already advanced destruction of the graft. Therefore, very potent immunosuppressive regimens are necessary to avoid small-bowel allograft rejection or even to reverse an ongoing rejection process. Cyclosporin was shown in small and large animal models to control rejection reactions sufficiently [4, 13]. However, there are two even more promising immunosuppressive agents currently under investigation. FK506, a macrolide lactone isolated from Streptomyces tsukubaensis, leads to long-term survival of small-bowel allografts in a rodent model and has already been used in a few clinical small-bowel transplantations [11, 14]. RS61443, a mycophenolic acid morpholinoethylester, selectively inhibits T- and B-cell proliferation [9]. We have investigated the use of FK506 and RS61443 for the reversal of small-bowel allograft rejection in a small animal model.     

Changes in the mononuclear cell subpopulations of rat cardiac transplant recipients administered FK506 for the treatment of ongoing rejection

The inhibitory effect on ongoing rejection and the changes that occurred in mononuclear cell subpopulations were compared between four groups of rats treated with FK506 or steroids. Group 1 was given no immunosuppressive drugs, group 2 was given FK506 from the day of grafting, group 3 was commenced on FK506 on the 4th day after grafting, and group 4 was commenced on methylprednisolone (MP) on the 4th day after grafting. The garft survival times in groups 2 and 3 were significantly longer than those in groups 1 and 4, and there were fewer CD3⁺ and CD4⁺ T lymphocytes in the peripheral blood in the groups treated with immunosuppressive drugs than in group 1. In group 4, the levels in both the peripheral blood and thymus were significantly lower than those in the groups treated with FK506 despite the fact that graft rejection occurred soon after the discontinuation of steroid administration. Moreover, the levels of interleukin-2 receptors and macrophages in groups 2, 3, and 4 were significantly lower than that in group 1 postoperatively; however, the number of macrophages in groups 2 and 3 was significantly lower than that in group 4 on the 10th day after transplantation. The findings of this study demonstrated that FK506, even if administered after rejection has begun, might inhibit the subsequent extensive allograft rejection more specifically and effectively than steroids, and that the measurement of a marker for macrophages in the peripheral blood could be useful for the detection of rejection following allograft transplantation in rats.     

Improved renal allograft survival in children treated with FK 506 (tacrolimus) rescue therapy

FK 506 has been reported to be effective in reversing acute renal allograft rejection that is resistant to steroids and to OKT3. The contribution of FK 506 “rescue” therapy to long-term graft survival has not been determined. We report 23 children transplanted between January 1993 and December 1994, 10 of whom received FK 506 “rescue” therapy. Acute rejection was reversed in 8 of 10, with 7 of the remaining grafts still functioning after a mean follow-up of 10.9±7.8 (SD) months (range 1 – 26 months). The actuarial 1-year graft survival rate was 86% compared with 66% for historical controls (P <0.05). We conclude that FK 506 may provide long-term benefits to children facing allograft loss due to acute rejection. Received August 15, 1995; received in revised form and accepted April 1, 1996     

小剂量FK778对大鼠移植肾慢性排斥反应的预防作用

目的探讨小剂量FK778对大鼠移植肾慢性排斥反应的预防作用。方法应用显微外科技术制作移植肾慢性排斥反应大鼠模型，将肾移植大鼠分为两组。肾移植后第16周开始治疗组大鼠接受FK778每日5mg／kg体重灌胃，对照组接受赋形剂。移植后每4周行24h尿蛋白含量测定，第24周处死大鼠，对移植肾组织行组织学、免疫组织化学及实时定量RT—PCR检测。结果治疗组大鼠蛋白尿、肾组织病理损害程度，淋巴细胞和单核／巨噬细胞浸润程度和对照组比较显著减轻，肾组织生长因子TGF-β基因的表达也减少。结论小剂量FK778能预防大鼠移植肾慢性排斥反应。移植肾组织T淋巴细胞和单核／巨噬细胞浸润减轻，TGF-β生长因子基因表达的减少，可能是其预防同种移植肾慢性排斥反应机制中的重要环节。     

Comparison of short and long-term renal function in liver transplant patients receiving cyclosporin or FK 506

Abstract Long-term renal function was compared in 49 liver recipients [25 patients received cyclosporin (CyA) and 24 patients received FK 5061 followed for a period of 1 year. Creatinine (CR) and glome-rular filtration rate (GFR) pre-transplantation (pre-Tx) and at 1, 3, 5, and 12 months post-Tx were recorded, as well as incidences of hyperkalemia, post-Tx hypertension, and insulin-dependent diabetes mellitus (IDDM) in the two groups. At 1 year post-Tx, the mean Cr had risen from baseline by 56% and 60% in the FK and CyA groups, respectively; the mean GFR had dropped by 32% in FK patients and by 27 % in CyA patients. Acute nephrotoxicity occurred in 1/25 CyA patients (217 required dialysis) and 9/26 FK patients (7/9 required dialysis; 211 were switched to CyA). None remained on dialysis at 3 months. Renal insufficiency persisted at 1 year in 7/16 patients with early toxicity (CyA, 4; FK, 3) and in 3 of the remaining 36 pts ( P < 0.001). Hyperkalemia occurred in 4/25 CyA, and in 12/24 FK patients ( P < 0.025), post-Tx hypertension occurred in 15 CyA, and 7 FK patients ( P < 0.05), and IDDM occurred in 4 CyA and 7 FK patients ( P = ns). FK 506 and CyA, thus, exerted similar chronic renal effects. Although acute renal insufficiency improved upon dose reduction, renal impairment was permanent in some cases.     

他克莫司和雷帕霉素对肝癌肝移植患者Foxp3+ Treg的影响及防治排斥反应的研究

目的 探讨免疫抑制剂他克莫司和雷帕霉素对肝癌肝移植受者Foxp3+ Treg产生的影响及其防治排斥反应的疗效.方法 自移植后第2个月到第12个月,每月采血,采用实时荧光定量PCR法检测他克莫司组和雷帕霉素组肝癌肝移植受者新鲜外周血单个核细胞中Foxp3 mRNA的表达水平,通过同期术后观察和实验室检查,比较两组受者间Foxp3 mRNA表达水平和急性排斥反应发生率的差异.结果 他克莫司组受者的外周血单个核细胞中Foxp3 mRNA表达水平(0.1032±0.0943)明显低于雷帕霉素组受者(1.2136±0.6738),差异有统计学意义(t=5.1610,P＜0.01);雷帕霉素组患者比同期他克莫司组受者术后急性排斥反应发生率明显减低,差异有统计学意义(x2=2.2222,P＜0.05).结论 他克莫司抑制了肝癌肝移植术后免疫耐受的诱导,而雷帕霉素可能参与了免疫耐受的诱导和维持;雷帕霉素对肝癌肝移植受者防治排斥反应的效果更好.     

FK506对大鼠心脏移植细胞凋亡的作用

目的　观察大鼠心脏移植急性排斥反应中的细胞凋亡现象及FK5 0 6对它的影响。方法　进行 48次SD→Wistar的大鼠颈部心脏移植 ,用苏木素 伊红 (HE)染色和原位末端标记(TUNEL)技术检测移植心切片 ,进行排斥反应的病理分级并计算凋亡指数 (AI)。结果　移植心的细胞凋亡主要发生于心肌细胞 ;FK5 0 6能明显减少心肌细胞的凋亡 ,减轻移植心的组织损伤。移植后第 3、5、7天AI对照组分别为 3.73± 2 .32、8.30± 2 .97、10 .2 2± 5 .5 2 ;FK5 0 6治疗组为 1.2 7± 1.2 0、2 .89± 2 .18、3.11± 1.6 8;两组比较差异有非常显著性 (P <0 .0 1)。结论　细胞凋亡是心脏移植急性排斥中组织损伤的重要机制 ;FK5 0 6能明显抑制心肌细胞凋亡 ,这可能是FK5 0 6发挥免疫抑制作用的重要方面。     

Co-administration of ketoconazole and tacrolimus therapy: a transplanted rat model

Background/aim The aim of this work is to study the effect of addition of ketoconazole to experimental kidney transplanted rat treated with tacrolimus and precludes the percentage of tacrolimus dose reduction. Material and methods The material of this work included 60 male Sprague Dawely rats subjected to renal allotransplantation. They were equally divided into five groups: Group I: served as control group, Group II: received FK506 3.2 mg/kg/bw, Group III: received FK506 2 mg/kg/bw, Group IV: received FK506 1 mg/kg/bw, Group V: received FK506 1 mg/kg/bw plus ketoconazole 20 mg/kg/day. FK506 trough level and laboratory investigations were determined at 0, 3, 7, 10, 14, and 27 days post-transplantation. Results In all groups loss of body weight was observed at day 27 after treatment compared to that before transplantation. Serum creatinine significantly increased at day 27 compared to the basal level in groups treated with 1.0 mg and 3.2 mg FK506 (1.80 ± 0.50 vs. 0.39 ± 0.06 P = 0.001) and (1.03 ± 0.26 vs. 0.50 ± 0.07 P = 0.001) respectively. While for 2.0 mg or 1.0 mg plus keto groups, no significant differences in serum creatinine levels over time (0.56 ± 0.22 vs. 0.44 ± 0.10 P = 0.106) and (0.55 ± 0.30 vs. 0.42 ± 0.08 P = 0.160) were observed. Conclusion Concomitant administration of ketoconazole and FK506 is safe and results in increase blood trough level concentration of FK506 with 50% dose reduction in transplanted rat model.     

The immunomodulatory effects of a novel agent, leflunomide, in rat cardiac allotransplantation

Abstract We assessed the immunomodulatory effect of leflunomide (LEF) in a heterotopic abdominal model of rat heart transplantation using a major histocom-patibility mismatch (DA X LEW). The endpoint of this study was cardiac rejection assessed by abdominal palpation of the ventricular impulse and confirmed by laparotomy and histology. In this study, LF was investigated using four dosages (5, 10, 20 and 30 mg/kg per day orally) against cyclosporine (CsA) (15 mg/kg per day orally) and FK506 (1 mg/kg per day orally). The ability of LEF to prevent rejection and reverse ongoing acute rejection was assessed. The results showed that untreated hearts were fully rejected by day 5 and that LEF at 5 mg/kg was significantly better than any other dose tested, was superior to FK 1 mg/kg, and was as effective as CsA 15 mg/kg in preventing rejection after a short course of treatment. After a longer course, 10 and 20 mg/kg LEF proved more effective than 5 mg/kg in controlling rejection and as efficacious as 1 mg/kg FK and 15 mg/kg CsA. In the control of ongoing established early rejection. LEF proved to be equally effective, even at lower doses (5 mg/kg), to CsA 15 mg/kg and FK 1 mg/kg. In the control of ongoing established late rejection, 20 mg/kg LEF proved to be superior to 10 mg/kg LEF and 15 mg/kg CsA, and was as effective as FK 1 mg/kg. However, when higher doses of CsA (25 mg/kg) and FK (2 mg/kg) were tested against 20 mg/kg LEF in this mode of rescue, LEF proved as effective as CsA and superior to FK. In the assessment of drug toxicity using body weight as a parameter, 20 mg/kg LEF proved safer than any other LEF dose tested, and safer than 15 mg/kg CsA and 1 mg/kg FK in both short- and long term administration. We conclude that LEF is a relatively safe and potent immunosuppressant with promising clinical potential.     

The superior effect of the combination of FK 506 and deoxyspergualin on rat cardiac allograft survival

In this present study, the effects of FK 506 and 15-deoxyspergualin (DSG), with respect to dose, timing, and combination, were investigated in an ACI-to-LEW rat cardiac allograft model. FK 506 was adminstered intramuscularly for 14 days starting on day 0 after grafting, while DSG was given intraperitoneally for 7 days starting on day 0,4, or 7 after transplantation. FK 506 or DSG monotherapy prolonged cardiac allograft survival in dose-dependent manners, and the minimum effective dose for overcoming rejection was 0.1 mg/kg per day in the case of FK 506 and 1.0 mg/kg per day for DSG. The graft survival rate was higher with administration of DSG starting on day 4 on day 0 after transplantation. A low dosage of FK 506 strating on day 0, in combination with DSG starting on day 0 or day 4 (but not on day 7), had a synergistic effect in prolonging allograft survival for 14.0±3.3 days and 25.4±8.2 days, respectively. The most effective combination treatment schedule for prolongation of allograft survival was FK 506 starting on day 0 and DSG starting on day 4 after transplantation.     

FK506 in pediatric kidney transplantation—Primary and rescue experience

Between 14 December 1989 and 17 December 1993, 43 patients undergoing kidney transplantation alone at the Children's Hospital of Pittsburgh received FK506 as the primary immunosuppressive agent. The mean recipient age was 10.2±4.8 years (range 0.7–17.4 years), with 7 (16%) children under 5 years of age and 2 (5%) under 2 years of age. Fifteen (35%) children underwent retransplantation, and 5 (12%) had a panel-reactive antibody level greater than 40%. Twenty-two (51%) transplants were with cadaveric donors and 21 (49%) were with living donors. The mean follow-up was 25±14 months; there were no deaths; 1- and 3-year actuarial graft survival was 98% and 85%. The mean serum creatinine and blood urea nitrogen were 1.2±0.6 mg/dl and 26±11 mg/dl; the calculated creatinine clearance was 75±23 ml/min per 1.73 m². Twenty-four (62%) patients have been successfully with-drawn from steroids and 24 (62%) require no anti-hypertensive medication. Improved growth was seen, particularly in pre-adolescent children off steroids. Between 28 July 1990 and 2 December 1993, 24 children were referred for rescue therapy with FK506, 14.6±16.4 months (range 1.1–53.2 months) after transplantation. Nineteen (79%) were referred because of resistant rejection; 4 (17%) were referred because of proteinuria; 1 (4%) was switched because of steroid-related obesity. There were no deaths; 1-and 2-year graft survival was 75% and 68%; 17 (71%) patients were successfully rescued, including 1 of 2 patients who arrived on dialysis; 4 (24%) of the successfully rescued patients were weaned off steroids. While not without side effects, which include nephrotoxicity, neurotoxicity, diabetogenicity, and viral complications, FK506 appears to be an effective immunosuppressive agent for both primary and rescue therapy after kidney transplantation. Its steroid-sparing qualities may be of particular importance in the pediatric population.     

FK506对大鼠坐骨神经再生作用的实验研究

押目的对FK506促神经再生的作用及药物应用方法进行初步探讨。方法雄性SD大鼠60只,随机分成三组,切断双侧坐骨神经制成坐骨神经再生室模型。A组(对照组)再生室内注入生理盐水;B组(全身用药组)再生室内注入盐水,颈后皮下注射FK5061mg/kg,连续14天;C组(局部用药组)再生室内注入1μg/mlFK506。于术后一定时间内观察神经损伤局部的免疫反应熏检测腓肠肌湿重、组织形态学及图像分析、电生理学。结果B、C组神经损伤局部淋巴细胞浸润程度较A组轻微。6周时B组各测定结果明显优于A组;C组各指标好于A组,但不具有统计学意义。结论穴1雪全身应用FK506(1mg/kg)具有神经保护和神经营养作用,可加快神经功能的恢复。(2)局部应用FK506(1μg/ml)对早期损伤神经有一定的保护作用,但对神经再生的促进作用不确切。     

Limited effectiveness of FK506 administration for ongoing rejection in heterotopic rat heart transplantation

A comparison was made of the histological findings for myocardial tissue of heterotopic transplanted rat hearts administered with FK506. ACI rats were used as donors and Lewis rats as recipients. FK506 was used for 6 days except for group I (control group). Group II received 0.32 mg/kg/day of FK506 from the day of operation while group III was given the same dosage from the 4th day after transplantation. Group IV was given 1.28 mg/kg/day of the agent from the day of grafting and group V received the same dose from the 4th postoperative day. The graft survival time was longer for all groups given FK506, but was significantly longer only for groups administered with FK506 from the day of operation. Histological studies performed 10 and 20 days after transplantation showed that a moderate rejection was seen in about half of the grafts receiving FK506 from the 4th day after grafting. An ultra-structural study of these cases showed that infiltrating large lymphocytes still remained in the interstitial tissues and that the cytoplasmic organelles of the myocytes had been focally destroyed. These results suggest that, although FK506 suppressed any further rejection, the effect might be limited and the myocardial changes of the cardiac graft might persist even after administration for ongoing rejection.This work was supported by a Ministry of Education Grant (A) 03770873.     

FK 506 as an alternative in cyclosporin-induced hemolytic uremic syndrome in a kidney transplant recipient

We describe a patient who received a living related kidney transplant that worked very well initially but developed oliguria and renal failure within 1 week and required dialysis. Clinical and hemological changes, as well as renal biopsy, confirmed the diagnosis of cyclosporin-induced hemolytic uremic syndrome. The patient did not respond to antirejection therapy or plasma exchange but did respond to the withdrawal of cyclosporin A and the commencement of FK 506.     

普乐可复在异种小肠移植中的作用

目的探讨免疫抑制剂普乐可复(FK506)对于异种小肠移植后迟发异种移植物排斥反应和细胞介导的异种移植物排斥反应的作用。方法采用仓鼠-大鼠动物实验模型,分为对照组和治疗组。治疗1组为单纯用FK506组;治疗2组为FK506加脾切除组。观察移植肠管吸收功能、体重、生存时间、FK506血药浓度及移植肠管苏木精-伊红染色。结果治疗1、2组的生存时间分别为(29.5±2.4)d和(106.6±26.3)d,与对照组(4.3±0.5)d相比显著延长(P<0.01);且治疗1、2组之间相比,差异亦有非常显著性意义(P=0.006)。术后第4d对照组苏木精-伊红染色可见绒毛萎缩,有大量炎性细胞浸润。治疗组小肠黏膜显示高分泌状态。术后126d治疗2组小肠肌层明显增厚、绒毛萎缩、肠壁小动脉壁纤维化。结论FK506可抑制异种小肠移植后迟发异种移植物排斥反应和细胞介导的异种移植物排斥反应;加脾切除可明显延长异种小肠移植的存活时间;但不能逆转异种小肠移植后所发生的慢性排斥反应。     

TIRC7 is induced in rejected human kidneys and anti-TIRC7 mAb with FK506 prolongs survival of kidney allografts in rats

TIRC7 delivers essential signals during immune activation as antibodies targeting TIRC7 inhibit lymphocyte proliferation and Th1 cytokine expression in vitro and prolonged kidney and heart allograft survival in vivo. Immunohistochemical analysis of biopsy specimens from human renal allografts undergoing rejection despite treatment with Calcineurin inhibitors (CI) showed elevated TIRC7 expression. Accordingly, with a view to clinical application, we evaluated the therapeutic effect of a chimerized anti-TIRC7 mAb in combination with Tacrolimus (FK506) using a rat kidney transplantation model (DA to Lewis). The combination of sub-therapeutic doses of both compounds significantly (p<0.05) prolonged the median graft survival to 19.5 days compared to monotherapy with FK506 (median survival, 7d) or mAb against TIRC7 (7d). These results suggest a potential synergism of anti-TIRC7 mAb and FK506 action, which could be developed into a novel combination therapy in the clinic by lowering side effects of present CI treatment. Moreover, the identification of TIRC7 in graft infiltrating lymphocytes might serve as a diagnostic marker to detect allograft rejection.     

Abdominal organ cluster transplantation in pigs and FK

Using a swine abdominal organ cluster transplantation model, we investigated the postoperative function and immunological reactions of a cluster graft and evaluated the immunosuppressive activity of FK506. The animals were divided into two groups. Group I (n = 6) served as controls, while in group II (n = 6) a daily dose of 0.1 mg/kg FK506 was given intramuscularly. Postoperative pancreatitis was the most important factor influencing the early outcome in both groups. In group I, the cause of late death was cachexia due to diabetes mellitus induced by pancreatic rejection. In group II, emaciation despite a well-functioning graft was the principal cause of late death. Histologically, in group I the grade of rejection in the pancreas was more severe than in the liver, and no sign of rejection was observed in group II. In conclusion, the pancreas suffered more severe rejection than the liver, and FK506 could significantly prevent cluster allograft rejection in this model.     

Cell traffic between donor and recipient following rat limb allograft.

Although cell traffic from the graft into the recipient and from the recipient into the graft had been noticed in allogeneic organ transplantation, little is known following whole-limb allografting. This study was conducted to define cell migration between donor and recipient. Sixty-seven vascularized hind limb allotransplantations were performed in rat sex-mismatched pairs and the recipient animals were treated with FK506 immunosuppression. The ratio of donor and recipient cells was evaluated by semi-quantitative PCR using the specific primers of the Y-chromosome. Allografted limbs had no rejection episode until the final assessment. The male recipient cells were detected in female limb grafts not at 1 week but at 48 weeks after transplantation. The male donor cells were detected in the humerus and tibia in the female recipient but not in the gastrocnemius muscle and leg skin. Our results demonstrated that recipient-derived cells gradually migrated into the grafted bone, muscle and skin cells with the duration of time. Donor-derived cells migrated into the healthy bones but not into the healthy muscle and skin. Because active regeneration occurs in the grafted limb to compensate graft damage secondary to ischemia and operative intervention, recipient-derived cells may mediate a muscular and dermo-epidermal renewal.     

Active TGF‐β1 Expression in kidney transplantation: a comparative study of Cyclosporin‐A (CyA) and tacrolimus (FK506)

Abstract Chronic rejection is a major cause of graft dysfunction following kidney transplantation. This fibroproliferative disease may be promoted by overproduction of transforming growth factor beta (TGF‐β). Previous studies have suggested that cyclosporin‐A (CyA) might increase production of this growth factor. The current study was designed to measure the expression of TGF‐β in renal transplant biopsies from patients immunosuppressed with either CyA or tacrolimus. Paraffin‐embedded renal biopsies were sectioned, dewaxed and incubated with primary antibody against active TGF‐β₁ antibody. After washing, the sections were treated with secondary antibody conjugated with fluorescein isothiocyanate (FITC). In each case the sections were assessed by semi‐quantitative scanning laser confocal microscopy. Biopsies from patients receiving CyA expressed significantly more active TGF‐β₁ than biopsies from patients receiving tacrolimus (P < 0.0001, Mann‐Whitney test). The increased level of active TGF‐β₁ expression in renal biopsies of patients receiving CyA may indicate a mechanism of chronic rejection.