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.     

A study of the mechanisms responsible for the action of new immunosuppressants and their effects on rat small intestinal transplantation

In a series of studies, using an identical rat intestinal transplantation model, we evaluated the effects of several drugs. FK-506 caused a significant attenuation in the proliferation of allogeneic CD4+ T cells and IFN-γ secreting effector functions. FYT720 resulted in a marked reduction in the numbers of lymphocytes, associated with a reduction of T cell recruitment, in grafts. An anti-MAdCAM antibody was next reported to significantly down-regulate CD4+ T cell infiltration in intestinal grafts by blocking the adhesion molecule, and could be useful as an induction therapy. Concerning TAK-779, this CCR5 and CXCR3 antagonist diminished the number of graft-infiltrating cells by suppressing the expression of their receptors in the graft. As a result, it reduced the total number of recipient T cells involved in graft rejection.As the next step, we focused on the participation of monocytes/ macrophages in this field. PQA-18 has been the focus of a novel immunosuppressant that attenuates not only the production of various cytokines, such as IL-2 & TNF-α, on T cells, but the differentiation of macrophages by inhibiting PAK2 as well.In this report, we summarize our previous studies not only regarding the above drugs, but on an anti-complement drug and a JAK inhibitor as well.     

Bombesin can minimize impairments of interstitial cells of Cajal induced by FK506 in small bowel transplantation

Purpose

Interstitial cells of Cajal (ICC) are known as intestinal pacemaker cells and express c-kit on their membrane. Previously, we reported that FK506 had neurotoxicity to enteric ganglia, and bombesin (BBS) preserved them against FK506. The aim of this study was to investigate whether ICC was impaired by FK506 and whether ICC was preserved by BBS against FK506.

Methods

Twelve rats underwent allogeneic SBTx heterotopically and were divided into 2 groups as follows: group A underwent SBTx with FK506 and group B with FK506/BBS. All rats were administered FK506 daily. Either BBS or normal saline was infused continuously from day 14 to 28. Analysis of ICC was performed immunohistochemically with c-kit. Interstitial cells of Cajal were evaluated by counting the number of c-kit-positive clusters in each graft.

Results

The expression of c-kit accumulated around 60% of PGP9.5-positive enteric ganglia. The number of c-kit-positive clusters in group A was 22.3 ± 5.5 clusters per cross section (C/CS) and that in group B was 36.3 ± 5.1 C/CS. Interstitial cells of Cajal were well preserved in group B. There was a significant difference between groups A and B (P <.001).

Conclusion

Interstitial cells of Cajal were impaired by FK506 in allografts, and BBS could minimize the impairment of ICC against FK506.     

Drug delivery system using microspheres that contain tacrolimus in porcine small bowel transplantation

Rejection remains a major barrier to successful bowel transplantation, in spite of improved immunosuppressive techniques. Therefore, new, more effective, immunosuppressants, with fewer side effects, are needed. Biodegradable microspheres containing tacrolimus (FK506) were used in an experimental porcine small bowel transplantation. Twenty pigs underwent transplantation and were divided into four groups according to the immunosuppressive regimen. Group A (n=5): no immunosuppression; group B (n=6): 0.2 mg/kg per day of FK506; group C (n=3): 1.0 mg/kg per day of FK506; group D (n=6): 0.04 mg/kg per day of FK506 contained in biodegradable microspheres. Rejection was diagnosed macroscopically by endoscopic examination and histologically by biopsy specimen analysis. The mean survival time and standard deviation (SD) were 8.8±3.5, 11.0±1.4, 9.7±2.5 and 28.6±22.5 days for groups A, B, C, and D, respectively, with a statistically significant difference found between group D, on the one hand, and groups A, B and C, on the other. The mean trough blood concentration of FK506 was 10.5±2.2, 27.9±6.0 and 10.5±3.5 ng/ml in groups B, C and D, respectively. In groups A and B, all pigs died of rejection, without infection. In group C, all died of infection, without rejection. In contrast, none of the pigs in group D developed rejection or infection. Our results clearly show that the drug delivery system using biodegradable microspheres that contain FK506 is effective for controlling rejection with fewer side effects in the porcine small bowel transplantation.     

Intraportal delivery of immunosuppression to intrahepatic islet allograft recipients

Local delivery of immunosuppressive agents may dampen local alloreactive events with avoidance of systemic toxicity. We investigated the innovative strategy of intraportal (IPO) delivery of three immunosuppressive agents in streptozotocin diabetic rat recipients of islet allografts (Lewis to Wistar-Furth) transplanted intrahepatically. IPO budesonide (BUD, 240 or 360 g/kg per day), a potent steroid, and cyclosporin (CyA, 2 or 4 mg/kg per day) did not prolong graft mean survival time [MST±standard deviation (SD)] as compared to nonimmunosuppressed recipients. Fourteen days of IPO FK 506 (0.16 mg/kg per day) significantly increased MST as compared with untreated controls (49±29 vs 7±1 days, P<0.01) and was more effective than intravenous (IV) FK 506 (17±7 days, P<0.01). When FK 506 was given for 28 days, the benefit of IPO over IV delivery was reaffirmed (MST 81±32 vs 34±4 days, P<0.01). The potential for toxicity was lessened by lower mean systemic levels in the IPO group as compared to the IV group (1.3±0.6 vs 3.5±0.9 ng/mg, P<0.02). The strategy of continuous IPO FK 506 was effective in the prevention of rejection of intrahepatic islet allografts.     

A novel small-molecule compound targeting CCR5 and CXCR3 prevents acute and chronic allograft rejection

BACKGROUND: Chemokines and chemokine receptors are critical in leukocyte recruitment, activation, and differentiation. Among them, CC chemokine receptor 5 (CCR5) and CXC chemokine receptor 3 (CXCR3) have been reported to play important roles in alloimmune responses and may be potential targets for posttransplant immunosuppression. METHODS: Fully major histocompatibility complex (MHC)-mismatched murine cardiac and islet transplant models were used to test the effect in vivo of a novel, small-molecule compound TAK-779 by targeting CCR5 and CXCR3 in acute allograft rejection. An MHC class II mismatched cardiac transplant model was used to evaluate its efficacy in chronic allograft rejection. Intragraft expression of cytokines, chemokines, and chemokine receptors was measured by quantitative real-time polymerase chain reaction and by histological analysis. RESULTS: Treatment of TAK-779 significantly prolonged allograft survival across the MHC barrier in two distinct transplant models. The treatment downregulated local immune activation as observed by the reduced expression of several chemokines, cytokines, and chemokine receptors. Thereby, the recruitment of CD4, CD8, and CD11c cells into transplanted allografts were inhibited. Furthermore, TAK-779 treatment significantly attenuated the development of chronic vasculopathy, fibrosis, and cellular infiltration. CONCLUSIONS: Antagonism of CCR5 and CXCR3 has a substantial therapeutic effect on inhibiting both acute and chronic allograft rejection. CCR5 and CXCR3 are functional in the process of allograft rejection and may be potential targets in clinical transplantation in the future.     

Bombesin can rescue the enteric ganglia from FK506 neurotoxicity on small bowel transplantation

Background/Purpose

FK506 has been reported to have neurotoxic effects. The aim of this study was to investigate whether FK506 causes neurotoxic effects on the transplanted graft enteric ganglia (TGEG) and whether bombesin (BBS) can prevent such atrophy.

Methods

Thirty rats heterotopically underwent small bowel transplantation and were divided into 5 groups as follows: group A, syngraft (SYN) alone; group B, SYN with FK506; group C, SYN with FK506 and BBS; group D allograft with FK506; group E, allograft with FK506 and BBS. From postoperative days 14 to 28, either BBS or normal saline was administered continuously. All recipients except for group A received FK506 daily. The ganglionic count was obtained by counting the number of protein gene product 9.5 immunohistochemically stained ganglia in the cross sections of each graft.

Results

The number of TGEG in groups A, B, and C was 69.7 ± 6.0, 51.5 ± 7.7, and 84.8 ± 10.2 ganglia per cross section, respectively. There was a significant difference between each group (P < .001). The number of TGEG in groups D and E was 44.6 ± 7.5 and 65.1 ± 9.5 ganglia per cross section, respectively. There was a significant difference between the 2 groups (P < .001).

Conclusions

FK506 causes severe neurotoxicity in transplanted grafts, and BBS protects graft enteric ganglia against the neurotoxic effects of FK506.     

他克莫司与新型免疫抑制剂FK778或FK779联合应用预防大鼠心脏移植排斥反应

目的 评价他克莫司（FK506）与FK778或FK779联合应用预防大鼠心脏移植排斥反应的效果。方法 大鼠异位心脏移植后单独应用FK506、FK778和FK779进行免疫抑制治疗，并设联合用药组。结果 单独用药组与不用药对照组相比，移植心脏存活时间明显延长，FK779组尤其显著；联合用药组移植心脏存活时间不但比对照组明显延长，而且明显长于各药同剂量单用组，FK506与FK779合用组尤其显著。结论 FK506、FK778和FK779均有很强的免疫抑制效应，FK506与FK778或FK779联合应用具有较强的协同效应。     

Effects of FK506 on experimental membranous glomerulonephritis induced by cationized bovine serum albumin in rats

Background. There have been no reports on the effect of FK506, a new immunosuppressive agent, on experimental membranous glomerulonephritis (MN) induced by an exogenous antigen. Therefore we investigated the effects of FK506 on MN induced by cationized bovine serum albumin (C-BSA) in rats. Methods. Two weeks after the rats were immunized with 1 mg of C-BSA and Freund's complete adjuvant, they received intravenous injections of 3 mg/kg of C-BSA 3 times weekly for 4 weeks. Rats were divided into four groups: group A (n=5) received intramuscular injections of 3 mg/kg of FK506 daily for 5 days beginning 2 days before the first immunization; group B (n=4) received 1 mg/kg of FK506 daily for 2 weeks beginning 2 weeks after the first immunization. Group D (n=5) received no FK506 and served as the control group. Rats were sacrificed 8 weeks after the first immunization. Results. Administration of FK506 in the preimmunization stage almost completely suppressed the development of MN in group A. Histological findings in groups B and C were similar to those in group D, the control group. However, urinary protein excretion was significantly lower in the group B(24±46 mg/day) and C (220±44 mg/day) than in group D (330±61 mg/day). Expression of intracellular adhesion molecule-1 in glomeruli and the number of leukocyte functioning-associated molecules-1 were significantly decreased in groups A, B, and C compared with the control group. Administration of FK506 was not associated with any significant side-effects or histological abnormalities. The whole-blood trough levels of FK506 in groups B and C were 9.1 ng/ml and 9.2 ng/ml respectively. Conclusions. The efficacy of FK506 was significantly increased when the drug was administered in the early phase of immunization in this model. The present study suggests that FK506 may be useful in patients with intractable nephrotic syndrome such as MN.     

T lymphocyte recruitment into renal cell carcinoma tissue: a role for chemokine receptors CXCR3, CXCR6, CCR5, and CCR6

Background

Evidence suggests that some patients with renal cell carcinoma (RCC) respond to immunomodulatory therapies that activate T lymphocytes. A prerequisite for effective T cell therapy is efficient targeting of effector T cells to the tumour site, yet the molecular basis of T cell recruitment to RCC is unknown. Furthermore, some T cells that naturally infiltrate this cancer are regulatory T cells (Tregs) that may suppress antitumour immune responses.

Objective

Determine the mechanisms of effector and regulatory T cell recruitment to RCC to allow targeted therapy that promotes local anti-tumour immunity.

Design, setting, and participants

Tumour-infiltrating and peripheral blood T cells were collected from 70 patients undergoing nephrectomy for RCC.

Measurements

T cells were analysed by multicolour flow cytometry for expression of 19 chemokine receptors and 7 adhesion molecules. Receptors that were expressed at higher levels on tumour-infiltrating lymphocytes (TILs) compared with matched peripheral blood lymphocytes (PBLs) were analysed further for their ability to mediate migration responses in TILs and for expression of corresponding ligands in tumour tissue.

Results and limitations

Three chemokine receptors—CCR5, CXCR3, and CXCR6—were significantly overexpressed on TILs compared with matched PBLs (n = 16 cases) and were capable of promoting migration in vitro. Their corresponding ligands CCL4-5, CXCL9-11, and CXCL16 were all detected in RCC tissue. However, since they were present in all cases studied, it was not possible to correlate ligand expression with levels of T cell infiltration. Foxp3⁺ Tregs were enriched within TILs compared with matched PBLs and expressed high levels of CCR5, CXCR3, and CXCR6, as well as CCR6, the ligand for which (CCL20) was detectable in RCC tissue.

Conclusions

Our data support a role for CCR5, CXCR3, and CXCR6 in the selective recruitment of T cells into RCC tissue and, together with CCR6, in the recruitment of Tregs.     

FK506和供体特异性输血在大鼠异位心脏移植中的作用

目的探讨FK506和供体特异性输血在大鼠异位心脏移植中的作用。方法利用大鼠异位心脏移植模型以了解在移植当天或移植术后第4日进行供者特异性输注（DST）的基础上,应用FK506能否延长移植物的存活。结果在移植当天行DST或单独用FK5061mg／kg连续10天,可将移植心中位存活时间从对照组的5天分别有效延长至7天和11天,而FK506与DST联合应用时并不产生增强效应。结论FK506和DST单独应用时虽均能延长大鼠同种移植心存活,但是它们没有协同作用。     

Efficacy of transient treatment with FK506 in the early phase on cyclophosphamide-induced bone marrow chimerism and transplant tolerance across MHC barriers

BACKGROUND: The use of mixed allogeneic bone marrow chimerism to induce donor-specific transplantation tolerance has been extensively demonstrated. In the present study, we assessed the effect of combined use of a short course of FK506 and a single-dose cyclophosphamide (CYP) on the induction of tolerance and development of GVHD after allogeneic BMT. MATERIALS AND METHODS: Lewis rat (RT1(l)) recipients received BMT from Brown Norway (RT1(n)) donors on the next day after injection of CYP at a dose of 200 mg/kg. The recipients were further treated with no FK506 (n = 8), 0.3 mg/kg/day FK506 on days 10-16 (n = 6), or the same dose of FK506 on days 0-6 (n = 6). In a subgroup of animals, heterotopic heart transplantation was performed to investigate transplantation tolerance. RESULTS: Six of eight recipient rats that did not receive FK506 died of severe GVHD, while high levels of chimerism were induced. Recipients of FK506 in the later phase developed mild transient GVHD around 2 to 3 weeks after BMT and recovered thereafter; however, the level of chimerism was significantly decreased (2.8 +/- 2.3% on day 100). Treatment with FK506 in the early phase completely prevented the development of GVHD and induced stable allogeneic chimerism in the long-term (13.8 +/- 8.3% on day 100). These recipients with stable chimerism accepted subsequent BN heart allografts indefinitely (>200 days x 5), while rejecting third-party (BUF) heart allografts by day 12. CONCLUSIONS: Early transient FK506 promotes the induction of stable bone marrow chimerism without GVHD after BMT with CYP pretreatment. The timing of treatment with FK506 is critical with a view to preventing GVHD and inducing stable long-lasting chimerism.     

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.     

Th17 lymphocyte levels are higher in patients with ruptured than non-ruptured lumbar discs,and are correlated with pain intensity

Background

Th17 lymphocytes have important roles in inflammation and autoimmune disease. Research on relationship between Th17 lymphocytes and pain associated with lumbar disc herniation (LDH) is limited. The purpose of this study was to examine the association of pain and Th17 lymphocyte and interleukin (IL)-17 levels in patients with herniated and non-herniated lumbar discs.

Methods

Thirty-four patients with single lumbar intervertebral disc herniation (median age, 44 years), and 17 healthy adults (median age, 37 years) were enrolled. Patients were divided into 2 groups depending on their magnetic resonance imaging (MRI) results and visual observations during surgery (group P, non-ruptured disc, n = 15; group E, ruptured disc, n = 19). Patients received posterior or transforaminal lumbar interbody fusion. Preoperative pain intensity was recorded using a visual analogue scale (VAS) score. The percentage of Th17 lymphocytes and IL-17 and prostaglandin E2 (PGE2) levels in peripheral blood were determined. Disc tissue was examined by immunohistochemistry for Th17 and IL-17 expression.

Results

Preoperative VAS pain scores were significantly higher in group E than group P (8.32 ± 1.04 vs. 6.33 ± 2.68, respectively, p = 0.009). Similarly, PGE2 level was greater in group E than group P (3.75 ± 1.41 pg/ml vs. 2.63 ± 0.89 pg/ml, respectively, p = 0.011). Compared to healthy controls (1.05 ± 0.19%), the percentage of Th17 cells was significantly greater in group P (1.52 ± 0.62%, p = 0.031), and the percentage in group E (2.99 ± 1.09%, p < 0.001) was significantly greater than in group P. The IL-17 expressions were similar. VAS pain score was positively correlated with Th17 proportion (r = 0.489, p = 0.003), and IL-17 concentration (r = 0.458, p = 0.007). PGE2 was also positively correlated with Th17 proportion (r = 0.539, p = 0.001), and IL-17 concentration (r = 0.500, p = 0.003). The expression of IL-17 was higher in the cells of group E and group P compared with normal tissue (p < 0.001).

Conclusions

Immune system activation is responsible, at least in part, for the pain experienced by patients with LDH, and increased levels of Th17 lymphocytes and IL-17 contribute to the pain.     

Immunosuppression with FK506 in rat arterial allografts: fate of allogeneic endothelial cells

PURPOSE: This study clarified the efficacy of low-dose FK506 and the possibility of discontinuing the use of FK506. METHODS: Fresh carotid arteries were allografted from ACI rats to Lewis rats. FK506 (0.2 mg/kg/day) was given intramuscularly from day 3 after transplantation until the rats were killed (group III), or it was given for 4 weeks and then discontinued (group IV). Isogeneic (group I) and allogeneic (group II) models served as untreated control groups. Grafts were harvested on days 0, 1, 3, 7, 14, 21, 28, 70, and 105 after transplantation. Histological evaluation and measurement of the endothelial cell (EC)-covered area were performed by means of scanning electron microscopy. RESULTS: In group I, ECs were denuded immediately after transplantation and subsequently regenerated within 2 weeks. In group II, after denudation and regeneration of ECs, massive leukocyte adhesion and subsequent destruction of regenerated ECs, followed by intimal hyperplasia, were observed. In group III, FK506 suppressed rejection almost completely, without intimal hyperplasia. In group IV, severe rejection and denudation of regenerated intima appeared 2 weeks after the use of FK506 ended. CONCLUSION: The denudation and regeneration of ECs may play an important role in the process of rejection and graft performance. FK506 proved to be successful in rat arterial allografting, and ECs of donor origin could survive on the allograft as long as FK506 was effective; however, cessation of the use of FK506 resulted in severe destruction of intima. To prevent allograft failure, long-term administration of an immunosuppressant is essential.     

Increased CXCR3 expression associated with CD3-positive lymphocytes in the liver and biliary remnant in biliary atresia

Background

Lymphocyte-mediated inflammatory damage of the bile ducts has been proposed as a potential mechanism in the pathogenesis of biliary atresia (BA). Chemokines regulate leukocyte migration and act as critical organizers of cell distribution in inflammatory responses. The aim of this study was to analyze the infiltration of T lymphocytes and the expression of a chemokine receptor, CXCR3, predominantly expressed on type 1 polarized T cells (T_H1, T_C1) in the liver and excised biliary remnants in infants with BA.

Methods

Immunohistochemistry for CD3, CD8, and CXCR3 was performed using liver biopsy specimens collected from the following 3 age-matched groups of patients: group 1, BA (nonsyndromic) at the time of Kasai portoenterostomy (n = 10); group 2, congenital choledochal dilatation (n = 2); and group 3, other cholestatic diseases including paucity of intrahepatic bile ducts and cholestasis (n = 3) related to total parenteral nutrition. Cellular staining on each section was graded from 0 to 4 and compared using nonparametric statistics.

Results

Infiltrating CD3⁺ and CD8⁺ lymphocytes in the portal tracts were significantly increased in group 1 (3.1 ± 0.4, 2.8 ± 0.4), compared with groups 2 (1.0 ± 0.0, 1.0 ± 0.0) and 3 (1.7 ± 0.3, 1.5 ± 0.5) (P < .01, P < .05). CXCR3⁺ mononuclear cells were significantly increased in group 1 (2.6 ± 0.3) compared with groups 2 (0.5 ± 0.5) and 3 (0.7 ± 0.3) (P < .05). They were mainly found in the portal tracts with a similar distribution to CD3⁺ cells. CXCR3⁺ cells and CD3⁺ cells also showed a similar distribution in specimens of biliary remnants from just below the portal plate.

Conclusions

Increased expression of CXCR3 associated with a significantly increased CD3 and CD8 T-cell infiltration suggests that CXCR3⁺ lymphocytes in a type 1 (T_H1, T_C1) cytokine milieu may play a role in the pathogenesis of BA.     

Allogeneic hepatocyte transplantation using fk 506

Hepatocyte transplantation is an intriguing alternative to orthotopic liver transplantation. While engraftment of syngeneic hepatocytes can be achieved with relative ease, engraftment of allogeneic hepatocytes has been far more complicated. We used FK 506 (Tacrolimus), a novel and highly efficient immunosuppressant, which has been reported to augment liver regeneration in rats. Recipients of isolated syngeneic (LEW) and allogeneic (Wistar F.) rat hepatocytes (major histocompatibility barrier) recieved different immunosuppressive regiments with FK 506 or Cyclosporine A (CsA). Mature syngeneic hepatocytes could be retrieved up to post op day 300 with the lowest number of hepatocytes on post op day 20. Following allogeneic transplantation, no mature hepatocytes could be identified after post op day 10, though ductular like structures within the spleen were found in FK 506 but not CsA-treated animals. The epithelial cells of ductular like structures exhibit cytological features of CK-19 positive cells. Our results suggest that under CsA or FK 506 immunosuppression long-term survival of mature allogeneic hepatocytes within the spleen cannot be achieved across a major histocompatibility barrier though FK 506 allows engraftment of allogeneic donor type ductular cells.     

Synergistic effects of malononitrilamides (FK778, FK779) with tacrolimus (FK506) in prevention of acute heart and kidney allograft rejection and reversal of ongoing heart allograft rejection in the rat

BACKGROUND: The effects of tacrolimus (FK506) and malononitrilamides (MNA) (FK778 and FK779) monotherapy and combination therapy were examined in prevention of acute heart and kidney allograft rejection and reversal of ongoing acute heart allograft rejection in the rat. METHODS: Brown Norway (RT1n)-to-Lewis (RT11) and ACI (RT1a)-to-Lewis (RT11) combinations were used, respectively, for heart and kidney transplantation models. Immunosuppressants were administered orally from day 1 to day 14 for preventing acute rejection and from day 4 to day 34 after transplantation for the reversal of ongoing acute rejection. RESULTS: In the prevention of acute heart rejection model, recipient rats treated with monotherapy of tacrolimus or MNA (FK778, FK779) showed a dose-related prolongation of mean survival time (MST) compared with naive control rats (P<0.01). The mean survival time in combination therapy of tacrolimus (FK506) and FK778 indicated that an additive to synergistic interaction was produced when compared with the respective monotherapies (combination index [CI]=0.631-1.022). These results were reproducible with tacrolimus and FK779 combination therapy (CI=0.572-0.846). Furthermore, similar results were also found in the prevention of acute kidney allograft rejection in the rat (CI=0.137-0.516). In the reversal of ongoing acute heart allograft rejection, combination therapy of tacrolimus and FK778 demonstrated a strong synergistic interaction (CI=0.166-0.970) compared with monotherapy of tacrolimus or FK778. CONCLUSIONS: Combination therapy of tacrolimus and MNA (FK778, FK779) produces synergistic effects in prevention of acute heart and kidney rejection and reversal of ongoing heart allograft rejection in the rat.     

FK 506 versus cyclosporin in the prevention of renal allograft rejection — European pilot study: six-week results

FK 506 was compared with cyclosporin in a randomised trial in good-risk cadaveric renal transplant recipients. The objective was to evaluate whether oral FK 506 dosing was viable and whether blood concentrations in the range 10–20 ng/ml would prove to be practical. Thirty-one adult patients were randomised to FK 506 and 16 to cyclosporin. Both groups received an identical regimen of azathioprine and corticosteroids. Serum creatinine concentrations decreased rapidly in both groups with mean values below 200 mol/l within 2 weeks. One graft in the cyclosporin group was lost due to renal vein thrombosis. During the 6-week study period, 19.4% of patients on FK 506 and 31.3% on cyclosporin experienced acute rejection. One patient in each group experienced corticosteroidresistant rejection that responded to anti-lymphocyte therapy. Infections were reported in 51.6% of the FK 506 group compared with 37.5% of the cyclosporin group. The spectrum of adverse events was similar in both groups. However, minor neurological disorders were more common in the FK 506 group (54.8% versus 6.3%) whereas hypertension was less common (48.8% versus 75.0%). The results indicate that oral FK 506 rapidly achieves therapeutic blood concentrations and is an effective immunosuppressant for the initial treatment of renal allograft recipients.     

Fk506 Inhibit Liver Regeneration in HOC Model Rat

BackgroundStudies have shown that lymphocytes support hepatic oval cell (HOC)-dependent liver regeneration and FK506（Tacrolimus） is known as an immunosuppressor. Therefore, we studied the role of FK506 in HOC activation and/or proliferation to guide the clinical use of FK506.MethodsThirty male Lewis rats were randomly divided into 4 groups: (A) intervene in activation (n = 8), (B) intervene in proliferation (n = 8), (C) control HOC model (n = 8), and (D) pure partial hepatectomy (PH) (n = 6). The HOC model was established by 2AAF(2-acetylaminofluorene)/PH in groups A to C. FK506 (at a dose of 1 mg/kg/d) was given subcutaneously in group A except on operation day, and not until day 8 post-operation (PO) in group B. Half of the animals were euthanized on days 10 and 14 PO, respectively. The remnant liver was weighed and stained by hematoxylin and eosin and immunohistochemical staining of proliferating cell nuclear antigen and epithelial cell adhesion molecule enabled HOC proliferation analysis.ResultsFK506 intervention exacerbated liver damage and hindered the recovery of the HOC model rat. Weight gain was severely retarded or even negative. Liver weight and the liver body weight ratio were lower than control group. HE and immunohistochemistry showed pooer proliferation of hepatocytes and fewer HOC numbers in group A.ConclusionFK506 inhibited HOC activation by affecting T and NK cells, ultimately blocking liver regeneration. Poor liver regeneration after auxiliary liver transplantation might be associated with the inhibition of HOC activation and proliferation caused by FK506 treatment.