Effective long-term immunosuppression maintained by low cyclosporine levels in primary cadaveric renal transplant recipients

Nephrotoxicity and cost are the major problems in the use of cyclosporine (CsA) in renal transplantation. Thus, maintenance of CsA levels at the lower limits of the therapeutic range is desirable. The lowest CsA level effective in preventing rejection while avoiding nephrotoxicity has not been defined. We report on 44 primary cadaveric renal transplant recipients treated with a protocol that involved a progressive reduction in the trough CsA levels. CsA was initiated at an oral dose of 15 mg/kg, and this dose was adjusted to achieve serum trough levels, as measured by radioimmunoassay, of 150-200 ng/ml during the first month, 100-150 ng/ml during the second month, 75-100 ng/ml during the third month, and 50-75 ng/ml thereafter. Patient and graft survival at 18 months were 94% and 83.6%, respectively. The mean daily CsA doses were 6.7 +/- 3.1 mg/kg at 6 months, 5.5 +/- 3.2 mg/kg at 12 months, and 4.7 +/- 2.4 mg/kg at 18 months. Corresponding trough serum CsA levels were 94 +/- 59 ng/ml, 64 +/- 22 ng/ml, and 44 +/- 21 ng/ml at 6, 12, and 18 months, respectively. Mean serum creatinine concentrations were 1.8 +/- 0.6 mg/dl at 6 months, 1.7 +/- 0.5 mg/dl at 12 months, and 1.6 +/- 0.5 mg/dl at 18 months. The mean serum creatinine concentration at 18 months was not significantly different from that of 18 conventionally treated primary cadaveric renal transplant recipients (1.6 +/- 0.5 vs. 1.4 +/- 0.4 mg/dl, P = .31). A total of 67% of patients did not have any rejection episodes under this protocol, while 71% of patients never developed CsA nephrotoxicity. No patient was taken off CsA for progressive nephrotoxicity. We conclude that trough serum CsA levels of 50-75 ng/ml, as measured by radioimmunoassay, are sufficient to maintain effective immunosuppression in the long-term management of primary cadaveric renal transplant recipients. These values are much lower than previously recommended, and this approach ameliorates chronic CsA nephrotoxicity.     

Long-term outcome of very early cyclosporine minimization and de novo everolimus therapy in kidney transplant recipients: a pharmacokinetic guided approach

Background

Cyclosporine (CsA) nephrotoxicity is an important cause of chronic allograft dysfunction. Clinical information concerning the impact of very early CsA dose reduction in kidney transplant recipients is limited. We have examined the long-term outcomes of very early CsA dose reduction. This is synchronized with de novo everolimus and steroid therapy.

Methods

We enrolled 10 de novo kidney transplant recipients to receive CsA (target C₀ 250–350 ng/mL) and prednisolone as initial therapy. CsA dosage was reduced by 50% at posttransplant day 7. Everolimus (target trough level, 3–8 ng/mL) was concomitantly started at the day of CsA reduction. Full pharmacokinetic studies of everolimus and CsA were studied at the period of 4–8 weeks after CsA reduction. CsA was then gradually reduced to maintain a trough level of 50–100 ng/mL and/or C_max <600 ng/mL.

Results

The mean follow-up was 51.2 ± 3.45 months. The nadir serum creatinine was 1.03 ± 0.33 mg/dL. The mean initial estimated glomerular filtration rate (eGFR) was 97.97 ± 23.36 mL/min. The mean initial trough everolimus was 5.2 ± 1.5 ng/mL. The eGFR at 1 year, 3 years, and last follow-up was 82 ± 25, 80 ± 21, and 80 ± 25 mL/min, respectively. Patient and graft survival was 100%.

Conclusion

Very early CsA dose reduction synchronized with de novo everolimus therapy was associated with good long-term patient and graft survival in kidney transplant recipients. This intervention can lead to 75% CsA minimization and is associated with very good GFR by the modification of Diet in Renal Disease Formula at year 4.     

Increased tacrolimus levels during diarrhea

While it is well known that diarrhea results in decreased trough levels of cyclosporin A, experience with levels of tacrolimus (FK506) and diarrhea is limited. We have therefore measured the tacrolimus trough levels of four male and two female recipients of solid organs before, during, and after gastroenteritis. The average age of these six patients was 31 (1–60) years. Four patients had received a kidney transplant, one patient had undergone simultaneous kidney-pancreas transplantation, and another patient had received a liver transplant. Rotavirus was identified in the feces specimen of a 1-year-old child that had undergone liver transplantation. All patients showed an elevated tacrolimus trough level (peak 20–60 ng/ml) after onset of gastroenteritis. Under symptomatic therapy and adequate adjustment of tacrolimus dose, the gastroenteritis stopped and tacrolimus levels returned to the therapeutic range. We recommend that FK506 levels be carefully monitored during diarrhea in order to prevent intoxication. Received: 17 May 2000 Revised: 12 December 2000 Accepted: 20 May 2001     

Cyclosporine plasma levels in renal transplant patients. Association with renal toxicity and allograft rejection

In 69 renal allograft recipients the highest-tolerated dose was given with respect to clinical events but without respect to the CsA plasma level (CsA-PL). The CsA dose was gradually decreased during the first 6-12 months after transplantation, and in some patients even later. The CsA dose after 12 months was 5-8 mg/kg/day and after 18 months 4-6 mg/kg/day, resulting in CsA-PL of 85-140 ng/ml and less than 50-110 ng/ml, respectively. CsA side-effects were usually seen in patients with high CsA-PL, but they were also encountered at levels normally seen in patients without toxicity. In the individual patient, acute CsA nephrotoxicity was associated with a significant rise in CsA-PL. In patients with acute nephrotoxicity a reduction of the CsA dose (mean 24%) was necessary to regain satisfactory renal function. All patients with several consecutive CsA-PL above 1000 ng/ml had hepatotoxicity or nephrotoxicity, or both, associated with severe morbidity and mortality. No difference was found between CsA-PL during acute rejection and during good renal function. The percentage of CsA determinations resulting in plasma levels below 50 ng/ml (the limit of detection) increased with the time of therapy and constituted 22% of all CsA-PL after 6 months of therapy. No rejections were seen later than 5 months after transplantation despite the low CsA-PL in many long-term treated patients. Treatment with high doses of methylprednisolone increased CsA-PL by 223%. Trimethoprimsulphamethoxazole in CsA-treated patients caused increases in serum creatinine levels. Monitoring of trough CsA plasma levels is recommended as a complement to clinical judgment. To avoid most nephrotoxicity and hepatotoxicity we have decided to keep the CsA-PL below 500 ng/ml during the first month, below 250 ng/ml the second month after transplantation, and below 200 ng/ml the third month after transplantation--and in long-term treated patients we now keep the CsA-PL between less than 50 and 150 ng/ml.     

The pharmacokinetics and immunosuppressive response of tacrolimus in paediatric renal transplant recipients

The aims of our trial were to study the pharmacokinetics of tacrolimus in paediatric kidney transplant recipients. The study comprised 25 patients (median age 13 years, range 2–20 years) followed for 12 months; five pharmacokinetics profiles (within the first and second week and after 1 month, 6 months and 12 months) were obtained. Patients were divided into two groups: six children <6 years old and 19 older children. Tacrolimus was given at an initial dose of 0.15 mg/kg twice a day. Blood samples were drawn before and 1 h, 2 h, 3 h, 4 h, 6 h, 9 h and 12 h after drug administration. Patient and kidney survival rates were 100% at 1 year. At 6 months and 12 months creatinine clearance was 68.5±16.3 ml/min per 1.73 m² and 64.0±15.2 ml/min per 1.73 m² body surface area, respectively. Tacrolimus trough levels were 7.8±1.9 ng/ml and 7.3±2.5 ng/ml. The area under the concentration–time curve for 0 h to 12 h (AUC_0–12) normalised to a dose of 0.15 mg/kg, increased with time from the kidney transplantation and stabilised after the 6th month post-transplantation. During the first month after transplantation the normalised tacrolimus concentration–time profiles were significantly greater in the older children (P<0.05); the actual doses were significantly greater in the younger children (P<0.05). In conclusion, initial doses of 0.15 mg/kg twice a day orally are safe and guarantee a satisfactory degree of immunosuppression, with our therapeutic regimen. Children <6 years old need to start with a 50% higher tacrolimus dose to achieve the same pharmacokinetic and immunosuppressive results.     

Dosing of MMF in combination with tacrolimus for steroiD-resistant vascular rejection in pediatric renal allografts

Abstract SteroiD-resistant vascular rejection was treated in seven adolescent renal allograft recipients using the combination of mycopheno-late mofetil (MMF) and tacrolimus (FK506). Since there are no published pediatric dose recommendations for MMF using this combination, trough concentrations and pharmacokinetic profiles were used for therapeutic drug monitoring. In order to keep the mycophenolic acid (MPA) concentrations between 2–5 μg/ml, mean MMF doses were reduced from 600 to 250 mg/m² b. i. d. Apparent clearance of MPA decreased from 5 to 1 ml/min per kg within 2 weeks. Pharmacokinetic monitoring revealed substantial variability among patients of both MMF and FK506. The MPA dose ranged from 178 to 1008 mg/m² per day to achieve an area under the curve (AUC) of 59.9 μg × h/ml ± 10.5 SD (range 49–65 μg). FK506 dose ranged from 1.3 to 8.8 mg/m² per day to achieve an AUC of 116 ng × h/ml ± 27 SD (range 83–145). We recommend adjusting MMF doses using therapeutic drug monitoring.     

Is There a Therapeutic Range for Monitoring Plasma Cyclosporin in Renal Allograft Recipients?

Sixty-two consecutive adult cadaveric renal allograft recipientshave been monitored by highperformance liquid chromatographyestimations of trough plasma cyclosporin (CsA) concentrationswithin 30 days of transplantation. The CsA estimations duringgraft rejection (mean $ 1 SD 218.6 $ 126.4 ng/ml) were not significantlydifferent from those obtained during stable renal function (232.3$ 172.8 ng/ml), whereas the estimations during episodes of nephrotoxicity(476.0$ 267.3 ng/ml) were significantly greater (P<0.001).During stable renal function 73.7% of estimations were withinthe therapeutic range of 100–350 ng/mI. However, 37.9%of estimations during nephrotoxicity and 76.7% of estimationsduring rejection episodes were also within this range. The therapeutic window for trough plasma CsA estimations isnot clearly defined. It seems that rejection episodes may occurat apparently adequate CsA concentrations, and although mostnephrotoxic episodes are associated with elevated concentrations,acute nephrotoxicity may occur at apparently therapeutic values.However, in this study, some patients at risk of nephrotoxicitywithin 30 days of transplantation were identified as early as7 days post-transplantation by the simple determination of themean trough CsA concentration for days 1–7.     

Tacrolimus reversibly reduces insulin secretion in paediatric renal transplant recipients.

BACKGROUND: Conflicting reports exist about the mechanism of tacrolimus-induced post-transplant diabetes mellitus. METHODS: We analysed intravenous glucose tolerance tests (IVGTT) of 14 paediatric renal transplant recipients on cyclosporin (CsA) microemulsion and 15 patients on tacrolimus (FK506). The groups were similar in age (13.2+/-4.2 vs 13.0+/-3.7 years), body mass index, serum creatinine concentrations (96+/-60 vs 97+/-44 micromol/l), time after renal transplantation, and cumulative steroid dose over 12 weeks prior to the test (3.4 vs 3.5 mg/m(2)/day, NS, Mann-Whitney). Parameters of glucose tolerance included glucose, insulin, C-peptide concentrations, and HbA1c. The mean concentrations of the primary immunosuppressant were similar to treatments employed in other centres (CsA 165+/-59 ng ml and FK506 7. 5+/-2.2 ng ml). RESULTS: Baseline glucose concentrations were significantly higher on FK506 therapy compared with CsA microemulsion therapy. Baseline insulin concentrations and C-peptide concentrations were identical in both treatment groups. FK506 trough levels correlated negatively with k values (glucose constant decay) in the FK506 group. There was a significant reduction of the insulin first-phase concentrations, both after 1 min and after 3 min in the FK506 group compared with the CsA group (112+/-17 vs 237+/-57 microU/ml, P=0.034). In patients with repetitive IVGTTs, glucose constant decay and insulin production improved after lowering FK506 whole-blood trough levels. CONCLUSIONS: We conclude that post-transplant glucose intolerance could be due to a dose-dependent, direct effect of FK506 on the pancreatic beta cell function, which can be controlled by dose reduction.     

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.     

采用程序化肾活检评估肾移植后低水平和标准水平他克莫司的疗效

目的以程序化肾活检评估低水平与标准水平他克莫司(FK506)的免疫抑制方案的疗效及其安全性。方法采用前瞻性、开放、随机对照研究,将48例首次接受尸体肾移植受者按随机数字分为两组:低水平FK506组(低FK506组,24例)和标准水平FK506组(标准FK506组,24例)。两组患者均采用麦考酚吗乙酯(MMF)+FK506+肾上腺皮质激素(激素)的三联免疫抑制方案,两组的MMF与激素用法相同。标准FK506组的FK506血药谷浓度:在入组后前3个月维持在10～12 ng/ml,3个月后维持在8～10 ng/ml。低FK506组的FK506血药谷浓度:入组后头2个月为8～10 ng/ml,第3个月为3～7 ng/ml,3个月后为3～5 ng/ml。术后定期随访1年,内容包括测定FK506血药谷浓度,检测肾功能[血清肌酐(Scr)、内生肌酐清除率(endogenous creatinine clearancerate,Ccr)]、空腹血糖、糖化血红蛋白、血清白蛋白、血脂。同时于术后3个月和12个月予以程序化移植肾活组织检查(活检),了解急性排斥反应(AR)发生情况、病理损伤指标评分及慢性移植物损伤指数(chronic allograft damage index,CADI)变化。观察术后1年的人、肾存活率及不良事件发生情况。结果移植术后1年,与标准FK506组比较,低FK506组:(1)FK506血药谷浓度较低(P<0.01),且达到目标水平的患者所占比例较高;(2)Ccr水平较高,(83±14)ml/min比(62±16)ml/min,P<0.05;(3)血糖水平较低(P<0.05);(4)根据程序化肾活检的结果,间质纤维化、肾小管萎缩和肾小球硬化评分较低(均为P<0.05);(5)AR发生率及其严重程度相似,术后1年人、肾存活率相近,均为100%(均为P>0.05)(6)术后1年的肺部感染与新发糖尿病的发生率较低(分别为P<0.05和P<0.01)。结论采用程序化肾活检评估疗效结果可靠,并有助于发现移植肾的慢性化改变,移植术后早期适度降低FK506血药谷浓度对于移植肾和患者均有较大益处,且不增加发生排斥反应的风险。     

Decreased cyclosporine exposure during the remission of nephrotic syndrome

In this paper, we report the pharmacokinetics changes observed in seven children with steroid-resistant nephrotic syndrome (SRNS). They received cyclosporine A (CsA) microemulsion 6 mg/kg/day and, one week later, they were admitted to perform a 12-h pharmacokinetic profile with eight time sample points. The pharmacokinetic profile was repeated at 24 weeks of treatment, when all patients achieved remission. Blood concentration against time curves were constructed for each patient at weeks 1 and 24 of CsA treatment. Peak concentrations (C _max) and the time needed to reach peak concentrations (t _max) were directly determined from these plots. The area under the curve (AUC) was estimated by the trapezoidal rule. There was a statistically significant difference of the AUC, trough levels, and t _max between weeks 1 and 24, with a decrease of AUC from 5,211 ng*h/ml in week 1 to 3,289 ng*h/ml in week 24, the trough levels decreased from 157 ng/ml to 96 ng/ml, and the t _max decreased from 1.85 h to 1.00 h. The higher CsA bioavailability during the nephrotic state has to be considered when managing patients, since the target AUC cannot be the same throughout the treatment.     

Safety of Conversion From Twice-Daily Tacrolimus (Prograf) to Once-Daily Prolonged-Release Tacrolimus (Advagraf) in Stable Liver Transplant Recipients

Nonadherence to immunosuppressive regimens among solid organ transplantation to range has been estimated from 15% to 55%. This problem has been identified as a leading cause of preventable graft loss. Tacrolimus once daily Advagraf has been developed to provide a more convenient dosing regimen to improve adherence. The aim of this study was to analyze the safety of a 1:1 dose conversion from twice-daily tacrolimus (Prograf) to Advagraf in 36 stable liver transplant recipients. The tacrolimus whole blood trough level at T0 was 6.7 ± 2.9 ng/mL with a daily dose of 3.7 ± 1.8 mg. The mean tacrolimus blood trough levels at T1 (7 days) and T2 (14 days) were 5.8 ± 2.5 and 5.8 ± 1.8 ng/mL with mean daily doses of 3.9 ± 1.9 and 4.1 ± 1.8 mg, respectively. There was no significant difference between T0, T1, and T2, either for tacrolimus blood trough levels or for tacrolimus daily dosages. Liver and renal function tests remained stable; no episodes of acute rejection were encountered after the conversion. A switching policy using a dose ratio of 1:1 from twice-daily tacrolimus to once-daily prolonged-release tacrolimus was safely applied to stable liver transplant recipients.     

用他克莫司替换环孢素A预防和治疗肾移植后慢性移植肾肾病

目的 观察用他克莫司（FK506）替换环孢素A（CsA）预防和治疗肾移植术后慢性移植肾肾病的有效性和安全性。方法 回顾性分析36例肾移植术后移植肾功能异常，病理检查确诊为慢性移植肾肾病（CAN）患者的临床资料。所有患者术后均采用以CsA为主的免疫抑制方案，临床确诊为CAN后，用FKS06替换CsA。FK506的起始剂量为原CsA剂量的1／50～1／100，维持剂量则根据患者的体重、发病情况、肾移植时间及FK506的血药谷值浓度确定，其他免疫抑制剂用量不变。观察换药后的移植肾功能变化，同时监测血糖、血脂和FK506的血药浓度。结果 用FK506替换治疗6个月后，患者的移植肾功能较替换前明显好转（P＜0．05），胆固醇、甘油三酯较替换前降低（P＜0．05），但血糖升高，出现新发糖尿病2例。结论 用FK506替换CsA可改善移植肾功能，提高移植肾的长期存活率。     

Safety and efficacy of conversion from twice-daily tacrolimus (prograf) to once-daily prolonged-release tacrolimus (graceptor) in stable kidney transplant recipients

Background

Graceptor is a new modified-release once-daily formulation of tacrolimus with an efficacy and safety profile similar to twice-daily tacrolimus (Prograf), as identified by clinical trials, offering a more convenient dosing regimen to improve adherence. The aim of this study was to analyze the safety of a 1:1 dose conversion from twice-daily Prograf to once-daily Graceptor in stable kidney transplant recipients.

Methods

We switched 33 Japanese patients who had undergone kidney transplantation ≥1 years before from twice-daily Prograf to once-daily Graceptor. The dose conversion ratio between Prograf and Graceptor was 1:1. We compared the following parameters: minimum tacrolimus concentration (C_min); concentration dose per weight (CDW); serum creatinine (sCr); blood urea nitrogen (BUN); total cholesterol (TC); high-density lipoprotein cholesterol (HDL-C); uric acid (UA); fasting blood sugar (FBS). Time points for measurements were 1 month before study start and 1 and 2 months afterward.

Results

The mean age of the subjects in this study was 46.5 ± 13.1 years. Mean C_min decreased from 4.55 ± 1.79 to 3.20 ± 1.22 ng/dL. The mean CDW also decreased, from 99.8 ± 69.5 to 75.0 ± 55.1 mg/dL/kg over the 2 months. There were no significant changes in sCR, BUN, UA, and FBS. Mean TC increased from 187.5 ± 51.4 to 194.3 ± 43.4 mg/dL, and mean HDL-C changed from 53.7 ± 12.0 to 56.1 ± 11 mg/dL. There were no episodes of rejection or infection.

Conclusions

We conclude that switching from Prograf to Graceptor is safe and has the advantage of improving adherence. It could also have a beneficial effect in controlling glycemic levels and the adverse effects of tacrolimus. In many cases (25%-30%), the minimum concentration of tacrolimus decreased after changing tablets. With Graceptor, the ratio of area under trough level to area under the curve (AUC) is low compared with Prograf, resulting in low C_min values of 1-2 ng/mL, and the AUC for Graceptor is very similar to that for Prograf.     

Renal function, efficacy and safety postconversion from twice- to once-daily tacrolimus in stable liver recipients: an open-label multicenter study

This multicenter, open-label, phase III study assessed renal function, safety, and efficacy in stable adult liver transplant recipients converted from tacrolimus twice-daily (BID) to once-daily (QD). Patients received tacrolimus BID for 6weeks before conversion to tacrolimus QD (1:1 [mg:mg] total daily dose basis) for 12weeks. Primary endpoint: change in steady state creatinine clearance (CrCl) between treatment phases. Of 112 patients enrolled, 98 were converted to QD dosing (full analysis set [FAS]). Mean (SD) tacrolimus dose was 3.7 (1.7) mg/day during BID and at conversion, and 3.9 (1.8) mg/day at Week 12. 74.5% of patients required no dose adjustment on conversion (FAS). Mean tacrolimus whole blood trough levels were at the lower end of the recommended range during tacrolimus BID and QD; the difference between mean steady-state trough levels was statistically significant (7.5ng/ml vs. 6.5ng/ml; P<0.0001). Following conversion, mean tacrolimus trough levels were reduced by 15% (about 1ng/ml) without any cases of acute rejection, remained stable during the remainder of the study, and were more consistent, showing reduced between- and within-patient variability in trough levels. Renal function remained stable, demonstrating noninferiority of tacrolimus QD versus BID (relative difference in mean calculated CrCl -0.1% [±6.3%]). Patient and graft survival were 100%. Adverse events incidence was low during both treatment phases.     

Renal hemodynamic effect of tacrolimus in renal transplanted children

Like cyclosporine (CsA), tacrolimus acts through the inhibition of renal phosphatase calcineurin. CsA induces reversible vasoconstriction, causing a transient reduction of renal plasma flow in patients with renal transplantation. The aim of this study was to determine the effect of tacrolimus on renal plasma flow in renal transplanted children. Eight children were studied with a median age of 10.6 years, a mean glomerular filtration rate (inulin clearance) of 55 ml/min per 1.73 m² (range 29–95), and a mean follow-up after transplantation of 5.6 months. Effective renal plasma flow (ERPF) was studied in each patient for 12 h after tacrolimus administration. Clearan- ces were obtained every 2 h for 12 h after drug administration. Tacrolimus pharmacokinetics was also studied. Average ERPF at the start of the test was 289 ml/min per 1.73 m² (range 177–404, SD±106). Variation in each of the 2-h periods was not significant, although a mild reduction of plasma flow was observed in three of the eight children. No correlation was found between tacrolimus AUC, peak, or trough levels and renal blood flow variations. Despite the relatively small number of patients studied, these data suggest that, in vivo, a therapeutic oral dose of tacrolimus is not necessarily followed by a significant reduction of ERPF in renal transplanted children. Received: 15 November 2000 / Revised: 3 April 2001 / Accepted: 16 May 2001     

Cyclosporine plasma levels six hours after oral administration. A useful tool for monitoring therapy

Clinical evolution and cyclosporine (CsA) monitoring of 65 transplanted patients (55 kidneys, and 10 kidneys and pancreases) treated with CsA were analyzed retrospectively (45 patients) and prospectively (34 patients). Our results showed the following: (1) nephrotoxicity is not uncommon even with low trough plasma levels of CsA; (2) the T6 value of a CsA pharmacokinetic plasma curve (6 hr after oral drug administration) is a valid expression of a full pharmacokinetic study; (3) when T6 was used prospectively as a monitoring tool and dose adjustments made disregarding concomitant serum creatinine levels, the latter decreased when CsA dose adjustments were made to correct toxic (greater than 350 ng/ml) or subtherapeutic (less than 100 ng/ml) T6, P less than 0.01. At present, serum creatinine for all our patients is 180.2 +/- 8 mumol/L, and no patient has needed to be switched to conventional treatment. The validity of trough plasma levels in patients under CsA oral administration once or twice a day seems questionable, and T6 proved to be more useful. Thus nephrotoxicity and CsA undertreatment may be avoided. This new monitoring tool (T6) will allow the utilization of lower doses of CsA and thus contribute to improved long-term graft function.     

Cyclosporine therapy monitored with abbreviated area under curve in nephrotic syndrome

Cyclosporin A (CsA) is an effective therapy for children with long-lasting nephrotic syndrome (NS). Long-term treatment can result in chronic CsA nephropathy (CsAN) and there is controversy concerning its incidence and severity. Trough levels are commonly used to monitor the drug concentration. We report a retrospective clinical and histological analysis of 18 children (12 males, 6 females) with steroid-dependent nephrotic syndrome (15 patients) and partially steroid-sensitive nephrotic syndrome (3 patients) treated with CsA for a long-term period (mean 4.9 years, range 2.2–6.9). Before CsA treatment all patients had normal creatinine clearance. CsA was started at a dose of 5 mg/kg per day administered orally in two divided doses and adjusted to maintain the mean CsA blood concentration between 250 and 350 ng/ml obtained from abbreviated area under the curve (AUC). A renal biopsy was performed after a mean period of 3.9 years (range 2.2–6.2) from the start of CsA treatment. Tubular, interstitial, and arteriolar lesions were evaluated in order to assess CsAN. The mean CsA dose and the mean CsA blood concentration were 4.4 mg/kg per day (range 3.6–5.8) and 276.6 ng/ml (range 162–346), respectively. No child had a worsening creatinine clearance during CsA treatment and follow-up after CsA discontinuation. If compared with the year before the start of CsA treatment, NS relapses and prednisone (PDN) dose significantly decreased during CsA treatment, 4/year versus 0.8/year (P <0.0001) and 0.9 mg/kg per day versus 0.2 mg/kg per day (P <0.0001), respectively. Histological analysis showed 15 patients with minimal change disease and 3 with focal segmental glomerulosclerosis. Clear-cut lesions diagnostic of CsAN were never found and only mild lesions were observed in 5 children (suggestive of CsAN in 2 patients and consistent with CsAN in 3 patients). Long-term CsA treatment is confirmed to be effective in preventing NS relapses and reducing PDN dose. Renal function is not a reliable indicator of CsAN. With the mean CsA blood concentrations used in our patients CsAN presented a low incidence (28%) and was generally mild. Renal biopsy should be performed 2–3 years from the start of long-term CsA treatment, especially if the mean CsA blood concentrations are not regularly monitored.     

Hypertrichosis and gingival hypertrophy regression in renal transplants following the substitution of cyclosporin by tacrolimus

Gingival Hyperplasia (GH) and hypertrichosis (HT) are two sides effects associated with the usage of cyclosporine (CyA) but not with tacrolimus (FK 506). The aim of this study is to evaluate the efficacy and security of the conversion from CsA to FK 506 to treat those two complications. From August 1996 to May 1997, 15 patients (9 males, 6 females) aged from 23 to 63 years old (38 +/- 14, mean +/- SD) were switched from CsA to FK 506, 12 for GH, 2 for HT and one for combined presentation. FK 506 was first initiated at a dose of 0.15 mg/kg/day and then adjusted to a level target of 8 ng/ml. The conversion was done on an out patient basis at average 35 (5-83) months after transplantation. Patients were followed prospectively for 12 months. There was a significant reduction in GH in all patients within 3 months. Five out 13 patients had a complete resolution of GH within three months of conversion, 9/12 within 6 months and all by 12 months. HT resolved completely within 6 months. No rejection episode occurred and the serum creatinin remain stable over one year post conversion. Conversion from CsA to FK 506 is thus a safe and valid option to treat CsA induced GH and HT.     

Maintenance cyclosporin monotherapy after renal transplantation-clinical predictors of long-term outcome

Background. There is considerable debate about whether maintenance cyclosporin (CsA) monotherapy is advisable or not in renal transplantation. Methods. Between August 1984 and December 1989, 463 adult patients received a first cadaver graft. Initial immunosuppression was sequential: antilymphocyte or antithymocyte globulins (10-14 days), prednisone and azathioprine were combined and CsA was introduced (6-8 mg/kg/day) when the antilymphocyte or antithymocyte globulins were discontinued. When the graft function was stable and the peak of preformed lymphocytotoxic antibodies was &les:25% and/or the number of rejection episodes was ⩽1, the steroid therapy was stopped within 1.5-3 months after transplantation, and azathioprine within 3-12 months. Patients with both anti HLA antibodies >25% and more than one rejection episode were excluded. Cyclosporin doses were adapted for whole-blood trough levels between 100 and 200 ng/ml (monoclonal antibody radioimmunoassay or high-performance liquid chromatography). Cyclosporin monotherapy was attempted in 234 of the 463 patients. Results. At the end of the investigation in January 1993 (follow-up time >36 months, mean 60.5±4.5 months), 135 patients were receiving CsA without steroids or azathioprine. The 99 CsA monotherapy failures were due to rejection episodes in 48 cases, CsA A nephrotoxicity in 26 cases, and other causes in 25 cases, including five deaths and four with poor compliance. Renal function was stable in patients with successful CsA monotherapy: mean creatininaemia was 124±10 &mgr;mol/l at the time of CsA monotherapy inclusion and 129±10 &mgr;mol/l at the end of follow-up (mean time of CsA monotherapy 52±6 months). The parameters for predicting monotherapy success were age (43.2 versus 27.8, P=0.0014), timing of trial inclusion ⩾6 months post-transplant (7.9&;plusmn; versus 5.3&;plusmn;3.1 months, P=0.04), and excellent and stable renal function at the time of inclusion (124±10 versus 145±32 &mgr;mol/l, P<0.001). Conclusions. Maintenance CsA monotherapy was effective in 58% of low-immunological-risk first-graft patients and probably did not jeopardize overall results of our first grafts: patient and graft survival were respectively 90 and 73% at 6 years. We propose this policy to avoid long-term complications of glucocorticoid and azathioprine in selected compliant recipients with low immunological risk, follow-up time post-transplantation >6 months, and stable creatinaemia levels.