Different evolution of trough and dose levels during the first year after transplantation for tacrolimus versus cyclosporine

At present, the two calcineurin inhibitors-cyclosporine (CsA) and tacrolimus (FK506)-are among the most frequently used immunosuppressants in clinical transplantation. Both drugs share variable oral bioavailability, which necessitates intense drug monitoring. This variability is attributed to large interindividual differences in drug catabolism by cytochrome P450 3A4/5 (CYP3A4/5) and drug efflux by P-glycoprotein (PGP). In addition, the activity of both CYP3A4 and PGP can vary substantially within the same individual due to environmental factors such as concomitant intake of inducing/inhibiting medications (eg, rifampicin/sporanox) or food substances (eg, grapefruit juice). More recently, an inducing effect of methylprednisolone on intestinal and hepatic CYP3A4 has been shown. Also, an influence of gender on CYP3A4 activity (being higher in women) has been reported. Once CsA and FK506 are absorbed and reach the bloodstream, both drugs are avidly bound to erythrocytes (up to 95% for FK506 and 50% for CsA) and plasma proteins, leaving only a small fraction of circulating active drug. This phenomenon also limits further hepatic catabolism and hence clearance of drug, which is influenced by hematocrit and levels of plasma proteins such as albumin. The aim of the present study was to compare the influence of changing steroid doses, hematocrit, and albumin on trough and dose levels of FK506 versus CsA during the first year after transplantation. In addition, the evolution of trough and dose levels of FK506 versus CsA was stratified according to gender.     

Alterations of CYP3A4 and P-glycoprotein activity in vivo with time in renal graft recipients

BACKGROUND: Catabolism by intestinal and hepatic cytochrome P450 3A4 (CYP3A4), and excretion by P-glycoprotein (PGP), has a major influence on oral bioavailability of calcineurin inhibitors. In this study, the activity of intestinal and hepatic CYP3A4 and PGP in vivo was assessed in renal transplant recipients during the first year after transplantation (Tx). METHODS: Stable Caucasian renal transplant patients were tested at 1 week, 3 months, and 1 year after Tx, and compared with the results obtained in drug-free healthy volunteers. Intestinal and hepatic CYP3A4 and PGP activity were determined by measurement of (14)C-excretion dynamics in breath and urine after oral and intravenous administration of [N-methyl-(14)C]-erythromycin. RESULTS: Compared with 1 week after Tx, intestinal and hepatic CYP3A4 activity significantly decreased at 3 months and 1 year after Tx (-33% and -45%; -7% and -33%, respectively). Compared with the healthy volunteers, intestinal and hepatic CYP3A4 activity of the patients was significantly increased at 1 week after Tx, but normalized at 1 year after Tx. A similar pattern, though not significant, was seen for intestinal PGP activity. CONCLUSION: Phenotypic expression of hepatic and intestinal CYP3A4 was increased immediately after Tx, but gradually decreased to basal levels toward the end of the first year after Tx. The most plausible explanation for this evolution was the tapering of corticosteroid (CS) doses. These findings may also explain the increasing bioavailability of tacrolimus with time after Tx.     

Impact of gastric acid suppressants on cytochrome P450 3A4 and P-glycoprotein: consequences for FK506 assimilation

BACKGROUND: Cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (PGP) are important determinants of the oral bioavailability and clearance of tacrolimus. Cimetidine and omeprazole are known modulators of several CYPs in vitro. In the present study, the impact of cimetidine and omeprazole on tacrolimus exposure and on CYP3A4/PGP activity in vivo was examined. METHODS: In a cohort of 48 renal transplant recipients who switched standard ulcer prophylaxis with 400 mg of cimetidine daily to 20 mg of omeprazole, dose/weight normalized trough levels of tacrolimus during a 5-day interval before and after switch were compared and further studied using multivariate analysis. In a cohort of 6 healthy volunteers, the effect of a 5-day course of ranitidine, cimetidine, and omeprazole on overall CYP, CYP3A4, and PGP activity in vivo was assessed with the (13)C-aminopyrin breath test and the combined per oral and intravenous (14)C-erythromycin breath and urine test. RESULTS: Dose/weight normalized trough levels of tacrolimus decreased significantly (-15%) after switch from cimetidine to omeprazole. In healthy volunteers, a significant increase of intestinal CYP3A4 activity was observed after omeprazole, whereas no change was noted after cimetidine/ranitidine. Overall CYP activity was significantly decreased after cimetidine and remained unchanged after omeprazole/ranitidine. No effects on PGP or hepatic CYP3A4 were seen. CONCLUSION: Switching treatment with cimetidine to omeprazole in renal transplant recipients is associated with a decrease of dose/weight normalized trough levels of tacrolimus. Studies in healthy volunteers suggest that this may be explained by an increase of intestinal CYP3A4 activity.     

Combined Therapy with Atorvastatin and Calcineurin Inhibitors: No Interactions with Tacrolimus

Increased systemic exposure to statins and consequent risk for complications has been reported in patients concomitantly treated with cyclosporin A (CsA). This has been ascribed to inhibition of drug catabolism by cytochrome P450 3A4 (CYP3A4) or drug transport by P-glycoprotein (PGP) and organic anion transporting polypeptide (OATP1B1). It is not known whether the combination of statins and tacrolimus (Tac) also suffers from this drawback.
Therefore, a pharmacokinetic study of atorvastatin and its metabolites was performed in 13 healthy volunteers after 4 days' treatment, and after short (12 h) concomitant exposure to CsA and Tac. A complementary assessment of overall CYP, and hepatic and intestinal CYP3A4 + PGP activity was performed after each treatment episode and compared to baseline (no drugs). Systemic exposure to atorvastatin acid and its metabolites was significantly increased when administered with CsA. In contrast, intake of Tac did not have any impact on atorvastatin pharmacokinetics. Concomitantly, a profound decrease of hepatic and intestinal PGP and an increase of intestinal CYP3A4 were noted with CsA, whereas no effect was seen after atorvastatin therapy with or without Tac. Based on these findings treatment with Tac appears a safer option for patients needing a combination of statins and calcineurin inhibitors.     

Nutritional immunomodulation leads to enhanced allograft survival in combination with cyclosporine A and rapamycin, but not FK506

BACKGROUND: Recently, specific immunonutrients were found to increase experimental allograft survival when combined with cyclosporine A (CsA). This study compared the effect on rat cardiac allograft survival when nutritional immunomodulation was used with CsA, rapamycin (Rapa), or tacrolimus (FK506). METHODS: Intra-abdominal ACI to Lewis cardiac allografts were performed and assessed daily by palpation. Study groups included untreated controls and those receiving CsA, Rapa, or FK506. Rats were fed ad libitum with Impact diet (fortified with fish oil, arginine, and RNA) or standard rat food. Further study groups were transplanted that received a donor-specific transfusion in addition to immunosuppression and diet. RESULTS: Allograft survival was extended by combining Impact with CsA (45.3+/-19 days) and Rapa (165.3+/-52 days), but not FK506 (12.4+/-3.2 days). Mean graft survival in the Rapa/Impact group met criteria for functional tolerance. The addition of a donor-specific transfusion did not lead to graft survival advantages over similar groups not receiving a donor-specific transfusion. CONCLUSIONS: The use of immunonutrients improves transplant outcome in animals treated with short courses of CsA and Rapa, but not FK506. These findings highlight the potential differences in the effects of nutritional immunomodulation with different immunosuppressive drugs in the treatment of transplant patients.     

他克莫司和环孢素A对肾移植术后患者肝功能影响的临床比较观察

目的:研究和比较他克莫司（FK506）以及环孢素A（CsA)对肾移植术后患者肝功能的影响。方法：将肾移植术后患者随机分为FK506组和CsA组,FK506组8例,CsA组26例。CsA组中出现肝功能异常的6例患者用FK506进行替换治疗。两组均联合应用霉酚酸酯（MMF）和泼尼松（Pred)。结果：观察6个月,FK506组和CsA组中急性排斥的发生率差异 不显著;FK506组中未发现肝功能异常患者,CsA组中有6例患者肝功能异常;肝功能异常的6例患者用FK506替换CsA后,总胆红素（TBIL）、直接胆红素（DBIL）、丙氨酸转氨酶（ALT）相继转为正常。结论：FK506免疫抑制剂效果与CsA相似,但对肝功能影响甚微,适合应用于术前有肝功损害或术后应用CsA后出现肝功能异常倾向的患者。     

Genetic Polymorphisms in CYP3A5 and MDR1 Genes and Their Correlations With Plasma Levels of Tacrolimus and Cyclosporine in Renal Transplant Recipients

Immunosuppressive drugs, such as tacrolimus (FK506) and cyclosporine (CsA), play an essential role in graft survival, preventing rejection. Large interindividual differences in drug-metabolizing enzymes as well as in drug transporters make the task of reaching the optimal concentrations difficult. The bioavailability of CsA and FK506 seems to be associated with the cytocrhome P450 IIIA (CYP3A) gene. It has also been described that the Multi Drug Resistance 1 (MDR1) gene that encodes for polyglycoprotein-P (P-gp) may influence the metabolizing action of FK506 and CsA. Therefore, we sought, to correlate single nucleotide polymorphisms (SNPs) in the CYP3A and MDR1 genes with the concentrations of FK506 and CsA. For this purpose we analyzed 2 groups of renal transplant recipients by sequencing: one receiving a CsA immunosuppressive regime, and other, an FK506-immunosuppression. This study showed that subjects in the FK506 group who had encoded the 1236C>T substitution in the MDR1 gene displayed 44.4% higher drug concentrations compared with (“wild-type”) individuals. Individuals carrying the 2677G>T,A mutation showed FK506 concentrations that were 44.7% higher than the wild-type individuals. Concerning the CsA group, individuals carrying the 22915A>C substitution displayed CsA concentrations 52.1% higher than wild-type individuals.     

FK506与CsA在肾移植术后抗排斥的临床应用

目的 比较他克莫司(FK506)与环孢素A(CsA)预防肾移植术后排斥反应的效果和安全性。方法 肾移植患者53例分成两组,FK506组为28例,CsA组为25例。其中CsA组因肝功能损害3例,难治性急性排斥反应1例而改换成FK506。FK506起始用0.2mg·kg~(-1)·d~(-1),CsA起始用6mg·kg~(-1)·d~(-1),同时分别联合应用MMF0.75g,每日2次口服,以及术后三天大剂量甲基强的松龙(MP)静滴,第三天改强的松口服,所有病例均严密观察并行血、尿等生化分析。结果 FK506组移植肾功能好,平均7.5天脱酐水平降至平均99.5μmol/L,2例出现排斥反应,经MP连续3d冲击后治愈。CsA组19例移植肾功能良好,6例出现急性排斥,其中3例经MP连续3d冲击后治愈,2例应用OKT3后急性排斥逆转,1例术后3d出现急性排斥经MP与OKT3治疗后改换成FK506,另3例肝损害呈进行性转氨酶升高改换成FK506。FK506组有血糖升高6例(18.8%),高血压5例(15.6％),感染7例(21.9％)。CsA组血糖升高2例(9.5％),高血压5例(23.8％),感染4例(19.0%)。结论肾移植术后应用FK506疗效确切,能有效防治难治性排斥的发生、发展,降低急性排斥的发生率,特别是在乙肝抗原阳性、肝功能受损者比CsA优越。     

Cytochrome P450 3A4 and P-glycoprotein Activity and Assimilation of Tacrolimus in Transplant Patients with Persistent Diarrhea

Renal transplant recipients suffering from persistent diarrhea have been repeatedly reported to have increased tacrolimus (Tac) trough levels. This study aimed to explore this phenomenon in detail in 15 renal transplant recipients with diarrhea, whose immunosuppression consisted of corticosteroids, mofetil mycophenolate and Tac. Both hepatic and intestinal CYP3A4 and PGP activity, important determinants of Tac bioavailability, were assessed, together with global CYP activity and investigations for gastrointestinal infection, function and morphology. Global CYP, CYP3A4, PGP and trough/dose levels of Tac were compared with diarrhea-free controls. In addition, a pharmacokinetic study of Tac was performed in 11 patients affected by diarrhea versus 9 controls. As expected, diarrhea was associated with increased Tac trough levels. An even stronger, significant increase of dose-normalized Tac levels was observed between 90 and 360 min after Tac intake. Time to peak concentration and drug half-life, however, were not altered. In addition, a concomitant decrease (+/-50%) of intestinal PGP activity was noticed in patients with diarrhea. For global CYP, CYP3A4 and hepatic PGP activity no such differences were noted. This pattern was not influenced by the specific cause of diarrhea. These data strongly suggest that persistent diarrhea is associated with an increased oral bioavailability of Tac.     

他克莫司替代环孢素A在肾移植术后肝功能损害患者中的应用

目的 :评价对肾移植术后肝功能损害患者用他克莫司 (FK5 0 6 )替代环孢素A(CsA)治疗的有效性及安全性。方法 :2 3例肾移植术后肝功能损害患者由CsA加霉酚酸酯 (MMF)加泼尼松 (Pred)方案改为FK5 0 6加MMF加Pred方案。FK5 0 6按 0 .1mg/kg·d-1剂量口服 ,随后根据血药浓度调整用量。结果 :2 3例患者除 1例因肺部感染死亡外 ,其余均在替代用药后 6 0d内肝功能恢复正常。有 6例患者出现血糖升高 ,1例血脂升高。 6例血糖升高者有 4例既往有糖尿病史 ,1例并发丙型肝炎。结论 :FK5 0 6替代CsA治疗肾移植术后肝损害患者效果好 ,无排斥反应发生、安全     

Effect of low dose cyclosporine and sirolimus on hepatic drug metabolism in the rat1.

BACKGROUND: We examined the effect cyclosporine (CsA) and sirolimus (SRL) alone and in combination on hepatic cytochrome P450-mediated metabolism in rats. METHODS: Rats were given 1 mg/kg of CsA or 0.4 mg/kg of SRL alone or in combination via constant intravenous infusion. Renal function was evaluated at the end of treatment. Blood samples were obtained to estimate CsA and SRL concentrations. Hepatic microsomes were prepared for immunoblotting and catalytic assays. RESULTS: CsA alone did not alter serum creatinine levels. SRL given alone or in combination with CsA produced a significant increase in urine output without changes in fluid balance. Although CsA and SRL administered alone caused damage to renal proximal tubules, the two-drug combination dramatically increased the renal structural damage. CsA alone suppressed cytochrome P450 (CYP) 3A2 protein levels by 39% (P=0.012) and catalytic activity by 30% (P=0.042). SRL alone reduced catalytic activity by 38% (P=0.012). Combination therapy reduced both CYP3A2 levels by 55% (P<0.001) and catalytic activity by 55% (P=0.001). CYP2C11 protein expression or catalytic activity were not changed in any group. CYP2A1 protein expression and catalytic activity were both significantly reduced in rats given CsA or/and SRL. Steady-state CsA levels were increased during concurrent SRL dosing, however, SRL concentrations were not changed by CsA coadministration. CONCLUSIONS: Concurrent SRL dosing increases CsA concentrations due to inhibition of hepatic CYP3A2 protein expression. Nephrotoxicity caused by combination therapy is due to CsA elevating levels of SRL or by SRL itself. Concurrent administration of CsA and SRL in transplant patients should be performed with caution.     

肾移植术后肝功能异常患者用他克莫司替换环孢素A疗效的初步观察

目的　观察他克莫司 (FK5 0 6 )替换环孢素A(CsA)并联合应用霉酚酸酯 (MMF)及泼尼松 (Pred)防治肾移植术后肝功能异常患者的有效性及安全性。方法　肾移植术后 8例肝功能异常患者 (男性 5例 ,女性 3例 ,平均 38.2 3岁 ) ,用FK5 0 6替换CsA治疗 ,停用CsA 2 4h后 ,开始给予FK5 0 6。FK5 0 6初始剂量根据患者体重、肝功能损害程度及术后时间确定 ,服药 1周后 ,根据全血FK5 0 6谷值浓度调整剂量 ,使其谷值浓度维持于 5～ 15 μg/L。结果　用FK5 0 6替换CsA ,1个月后患者血中直接胆红素从替换前的 (2 2 .6 6± 17.19) μmol/L下降至 (7.0 5± 2 .32 ) μmol/L ,P <0 .0 5 ;间接胆红素从替换前的 (4 2 .15± 34.15 ) μmol/L下降至 (14.5 4± 2 .5 9) μmol/L ,P <0 .0 5 ;血清丙氨酸转氨酶从替换前的 (83 .0 0± 93 .14)IU/L下降至 1个月后的 (2 9.5 0± 15 .41)IU/L ,P >0 .0 5 ;血清肌酐从 (177.91±86 .41) μmol/L下降至 (135 .92± 34.0 5 ) μmol/L ,P >0 .0 5。 3例腹水的患者均于药物替换 1个月后完全消失。仅有 1例患者出现便秘、食欲下降伴上肢颤抖。结论　用FK5 0 6替换CsA并联合应用MMF及Pred对防治肾移植术后肝功能异常是安全和有效的措施     

肝炎病毒携带者肾移植术后他克莫司的应用体会

目的：探讨肝炎病毒携带者肾移植术后应用他克莫司（FK506）的临床意义。方法：将59例肾移植受者（年龄＜55岁）分为两组，即肝炎病毒 携带者组（21例）和非肝炎病毒携带者组（38例）。观察肝炎病毒携带者和非肝炎病毒携带者肾移植术后应用FK506初始剂量的血药浓度，以及术后3个月，半年维持剂量的变化，并观察肝功能和急、慢性排斥反应的发生情况。结果；在相似的初始剂量下，肝炎病毒携带者组FK506血药浓度明显高于非携带者组，而且术后3个月及半年FK506维持剂量又明显低于非携带者组；术后3个月两组各有2例肝功能异常；随着观察时间的延长，有15例非肝炎病毒携带者因血药浓度偏低和维持剂量一直偏高，难以承担昂贵药费或发生急、慢性排斥反应，先后改用环孢素A。结论：肝炎病毒携带者肾移植术后免疫抑制剂应首选FK506，既减轻和避免药物副作用，药费也相对较低。     

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.     

Differences in Type 1 and Type 2 intracytoplasmic cytokines, detected by flow cytometry, according to immunosuppression (cyclosporine A vs. tacrolimus) in stable renal allograft recipients

Recent multicenter, randomized clinical trials have shown that in renal transplant patients tacrolimus (FK506) was more efficient than cyclosporine A (CsA) at preventing acute rejection. In order to try and evaluate whether this difference was related to a different in vivo T-cell suppression we assessed, in a prospective study, the frequencies of interleukin (IL)-2-, IL-4-, IL-5-, IL-6-, IL-10-, interferon-gamma (IFN-gamma)- and double-positive IL-2/IFN-gamma-producing whole T cells, CD4 + and CD8 + T-cell subsets by means of cytokine flow cytometry. This was performed after in vitro stimulation of peripheral blood mononuclear cells (PBMCs) with phorbol myristate acetate (PMA) and ionomycin, in the presence of monensin, in 14 healthy volunteers (controls) and in 14 renal transplant patients. The immunosuppression of the latter was based either on CsA (n = 7) or on FK506 (n = 7). Cytokine-expressing T-cell frequencies were assessed immediately pretransplantation (DO), and subsequently 3 months (M3) and 6 months (M6) afterwards in fasting patients prior to the morning intake of the immunosuppressive drug. We found that at DO the frequencies of IL-2-(22 +/- 2% vs. 22.2 +/- 2%), IFN-gamma-(26 +/- 3% vs. 29 + 3.4%) and IL-4-(0.8 +/- 0.2% vs. 1.4 +/- 0.2%)-expressing T lymphocytes were not significantly different between the controls and the patients, respectively. Conversely, the frequency of IL-2/IFN-gamma double positive cells was higher in the latter (9.3 +/- 1.6%) than in the controls (5.6 +/- 0.8); p = 0.06. Finally, on D0 the frequencies of IL-5-, IL-6-, and IL-10-producing T lymphocytes were lower than 1%, in both groups, as well as after grafting, i.e. on M3 and M6. As compared to baseline (DO): (a) chronic immunosuppression significantly decreased the frequencies of IL-2-, IL-4- and IL-2/IFN-gamma-expressing T cells, whereas those of IFN-gamma, IL-5, IL-6, and IL-10 were not significantly affected; (b) the frequencies of cytokine-expressing T cells were not statistically different between M3 and M6; (c) the decrease in the frequencies of IL-2- and IL-2/IFN-gamma-expressing T cells affected CD4 + and CD8 + cells equally; (d) there was a marginal decrease in the frequency of IFN-gamma-expressing cells only in the CD4 + subset but not in the CD8 population; and (e) for CsA, but not for FK506, the frequency of the IL-2-expressing T cells was negatively correlated with the whole blood trough levels. When we compared the frequencies of cytokine-expressing cells in FK506- and CsA-treated patients, we found that the frequency of IL-2-expressing T cells was significantly lower with FK506 (10.9+/-1.61%) than with CsA (16.3 +/- 1.8%; p = 0.03), whereas the frequencies of the other cytokine-expressing cells were not statistically different between the two groups. In conclusion, our study clearly demonstrated that studied ex vivo, FK506 and CsA decrease the frequencies of cells expressing IL-2, IL-4 and IL-2/IFN-gamma in vivo but do not affect those expressing IFN-gamma. Meanwhile, the frequency of IL-2-producing T cells was more affected with FK506 than with CsA and was negatively correlated with the CsA trough level. Finally, our results regarding IL-2 might explain to some extent the higher efficiency of FK506 in vivo than CsA.     

Morphological findings in non-episode biopsies of kidney transplant allografts treated with FK506 or cyclosporine

Abstract We conducted an analysis of biopsy specimens of non-episode renal allografts from patients treated with tacrolimus (FK506) or cyclosporine (CsA) to evaluate chronic drug-induced nephropathy in stable allografts. A total of 38 biopsy specimens from stable functioning renal allografts were examined. The patients had been treated with FK506 ( n = 16) or CsA ( n = 18) as main immunosuppressant for 0.3 to 7.4 years. Of the 38 biopsy specimens, 15 showed mild drug-induced arteriolopathy (hyalinosis or insudative change of arterioles and small arteries) with stripeD-form interstitial fibrosis, 10 showed minimum interstitial cellular infiltration (borderline rejection), 2 showed IgA nephropathy, 4 showed evidence of chronic rejection (transplant nephropathy) and 12 showed no abnormal findings. Of 34 renal allograft biopsy specimens with stable function, 22 (65 %) showed pathological evidence of drug-induced nephropathy. There were no significant qualitative or quantitative differences between FK506- and CsA-associated nephropathy.     

CYP3A5基因多态性对中国肾移植受者他克莫司血药浓度和疗效的影响

目的研究CYP3A5基因多态性对肾移植受者他克莫司（FK506）血药浓度／剂量比（blood drag concentration／dose,C／D）,术后急性排斥反应（AR）及不良反应发生率的影响。方法采用聚合酶链反应-限制性片段长度多态性技术检测’肾移植受者CYP3A5基因型,并以直接测序法进行验证。比较不同基因型患者之间的FK506C／D值,AR、不良反应的发生率。结果肾移植术后3个月内,＊3／＊3基因型患者FK506的C／D值为149±59,明显高于＊1／＊1基因型和＊1／＊3基因型患者的78±24和90±42（均为P〈0．05）;移植术后3个月内＊1／＊1基因型患者的AR发生率与＊1／＊3基因型和＊3／＊3基因型患者的AR发生率比较差异无统计学意义。＊1／＊1基因型和＊1／＊3基因型患者比较,＊3／＊3基因型患者术后肝功能异常、药物肾毒性不良反应的发生率较高（均为P〈0．05）。结论CYP3A5基因多态性对服用FK506肾移植患者的C／D值、肝功能异常、药物肾毒性有一定影响。CYP3A5＊3／＊3基因型患者的FK506的C／D值、肝功能异常和药物肾毒性不良反应的发生率较高。     

肾移植术后应用他克莫司的临床观察

目的 观察他克莫司（ＦＫ５０６）作为免疫抑制剂的有效性和安全性。方法 将首次接受同种异体肾移植的３５例患者随机分为２组,一组给予他克莫司,硫唑嘌呤（或霉酚酸酯）和泼尼松（ＦＫ５０６组）,另一组给予环孢素Ａ、硫唑嘌呤（或霉酚酸酯）及泼尼松（ＣｓＡ组）,观察２个组的免疫抑制效果及药物的副作用。结果 ＣｓＡ组和ＦＫ５０６组的人／肾１年存活率分别为１００．０％／９３／３％和９５．０％／９５．０％;两组肝和     

Pharmacological preconditioning with low-dose cyclosporine or FK506 reduces subsequent ischemia/reperfusion injury in rat kidney.

BACKGROUND: Ischemia/reperfusion (I/R) injury in the early posttransplant period is closely associated with delayed recovery of graft function, increased acute rejection, and late allograft dysfunction. Pharmacological preconditioning with low-dose cyclosporine (CsA) or FK506 was performed to induce ischemic tolerance in rat kidney with I/R injury. METHODS: Low-dose CsA (3 mg/kg, administered i.v.) or FK506 (0.3 mg/kg i.v.) were used to induce ischemic tolerance in Sprague-Dawley rats, and the induction of heat shock protein (hsp) 70 by CsA or FK506 was evaluated overtime. Rats were pretreated with CsA or FK506 6 hr before I/R injury when hsp70 was maximally expressed, and were killed 24 hr later. The effect of pharmacological preconditioning on subsequent I/R injury was evaluated in terms of renal function, histopathology score, assays for apoptosis (DNA fragmentation analysis, TUNEL staining, expressions of pro-apoptotic genes, and caspase activity), and the expression of inflammatory cytokine genes (interleukin-1 and tumor necrosis factor-alpha). RESULTS: Preconditioning with low-dose CsA or FK506 significantly improved renal function and renal histology, compared to rats with I/R injury. Apoptotic cell death (typical DNA laddering and increased TUNEL-positive cells) in rat kidneys with I/R injury, was decreased by pretreatment with low-dose CsA or FK506. Increased expression of pro-apoptotic genes (Fas, Fas-ligand, caspase 1 and 3) and activated caspases in ischemic rat kidneys were decreased after CsA or FK506 pretreatment. CONCLUSIONS: Pretreatment with low-dose CsA or FK506 prevents subsequent I/R injury, and this effect may be related to the induction of hsp70. Pretreatment of renal donors with low-dose CsA or FK506 may result in an improvement in immediate posttransplant function.