Normal glomerular filtration rate in long-term follow-up of children after orthotopic liver transplantation

BACKGROUND: Cyclosporine A (CyA) and tacrolimus are the principal immunosuppressive agents used for OLT in children. However, progressive deterioration of renal function from calcineurin inhibitor toxicity after OLT has been widely reported. The aim of this study was to assess long-term renal function in children after OLT. METHODS: We reviewed all OLT patients surviving >1 year at Sainte Justine Hospital from 1987 to 2003. The GFR (ml/min/1.73 m) was measured yearly by the Tc-99m DTPA single injection technique RESULTS: In all, 101 OLT patients (27 tyrosinemia, 33 biliary atresia, 5 fulminant hepatic failure, 36 miscellaneous) were studied. Median age at OLT was 35 months (range 6-178 months) in tyrosinemia group and 58 months (range 1-226 months) in the "Others" (P = NS), median pediatric end-stage liver disease score was respectively 3 (range -9 to 21) and 15 (-9 to 35), (P=0.001), and median follow-up was 6 (range 1-14) and 6 (range 1-17) (P = NS) years, respectively. Median annual GFR values in tyrosinemia fluctuated between 61 and 104 ml/min/1.73 m, with an improving tendency, and 94-121 ml/min/1.73 m in the Others. GFR did not differ on CyA vs. tacrolimus treatment. The median duration of therapy with calcium-channel blocker in the tyrosinemia group was 5 (1-13) vs. 2 (1-13) years in the Others. CONCLUSIONS: Median GFR remained normal in most nontyrosinemia patients (Others). Tyrosinemia patients remained stable at a lower GFR. CyA administration in three daily doses and prolonged calcium-channel blocker therapy may have contributed to this stability. Impairment of kidney function was associated with congenital kidney disease, toxic kidney injury, and portal hypertension.     

Decline in 51Cr-labelled EDTA measured glomerular filtration rate following lung transplantation.

BACKGROUND: The nephrotoxity of calcineurin inhibitors in lung-transplanted patients is well described, but previous studies have estimated rather than directly measured glomerular filtration rate (GFR). This study describes the decline of measured GFR in a large cohort of lung-transplanted patients from a national centre, and the correlation between measured and calculated GFR. METHODS: All lung-transplanted patients 1992-2004 (n = 390) were included in a longitudinal analysis. Seven patients were excluded due to retransplantation. Pre- and post-transplant parameters included (51)Cr-labelled EDTA clearance (mGFR) and the Cockcroft-Gault calculated clearance (cGFR). Trough cyclosporine levels (C0) and demographic and transplant information were also included in the analysis. RESULTS: A total of 66959 C0 and serum creatinine and 1945 mGFR measurements pertaining to 383 patients were included in the analysis. Pre-transplant mGFR was significantly lower with respect to recipient age over 60 years; and patients with a referral diagnosis of pulmonary hypertension had a lower mGFR and higher baseline serum creatinine levels than patients with emphysematous disease (P < 0.05). There were linear correlations between log(10) mean interval serum creatinine and log(2) mGFR at all time points pre- and post-transplantation (P < 0.0001, Spearman correlation coefficient = -0.81) and between log(2) cGFR and log(2) mGFR (P < 0.0001, Spearman correlation coefficient = 0.81), however, the agreement between mGFR and cGFR was poor (-2.7 +/- 38.6 ml/min). A simplified repeated measure ANOVA model describing post-transplant GFR over time demonstrated a 54% decline in mGFR within the first 6 months post-transplant. Pre-transplant mGFR was an important determinant of 6 month post-transplantation mGFR. Increasing mean C0, body mass index and early acute renal failure were independent risk factors for a more rapid decline in post-transplant mGFR. CONCLUSION: mGFR decreases dramatically during the first 6 months after lung-transplantation. Avoidance of high dose calcineurin inhibition may postpone the onset of post-transplant end-stage renal failure.     

Circadian rhythm of glomerular filtration rate in patients after kidney transplantation

Within 6 months of a kidney transplantation the graft can beregarded as an organ deprived of its innervation. We analysedwhether the transplanted kidney has a diurnal rhythm of itsglomerular filtration rate (GFR) similar to the GFR rhythm thathas been demonstrated in normal individuals and in patientswith nephrotic syndrome. GFR was measured by inulin clearancesevery 3 h during 1 day of bed-rest and identical food and fluidintake per 3 h in seven patients, 4–7 months after a successfulkidney transplantation, and in 10 healthy volunteers. Similarto these healthy subjects, a normal circadian rhythm of GFRwas detected in all but one patient with a maximum of 57 (range45–82) ml/min in daytime, a minimum of 47 (range 36–70)ml/min during the night and a relative amplitude of 21 (range10–41)%. The circadian rhythm of GFR was absent in thepatient with the lowest value of GFR (39 ml/min). In conclusion,GFR has a circadian rhythm in patients studied within 6 monthsof a kidney transplantation, despite the absence of renal innervation.     

西罗莫司在肝移植术后钙调素类抑制剂相关肾损病人中的应用

目的 探讨西罗莫司对肝移植术后钙调素类免疫抑制剂相关肾功能损害病人的肾功能的改善作用及安全性.方法 对11例肝移植术后出现钙调素类免疫抑制剂相关肾损害病人进行西罗莫司转换治疗,同时减少或完全停止钙调素类免疫抑制剂的应用.观察转换治疗后病人的肾功能、肝功能、急性排斥反应的发生及药物副作用等情况.结果 随访至今所有病人均存活,随访时间6～23个月.转化治疗后所有病人的肾功能均有不同程度的改善,6个月后血肌酐从(163.8±47.9)μmol/L降为(108.1±26.6)μtmol/L(P<0.05);除1例病人出现转氨酶升高,加用钙调素类免疫抑制剂后恢复正常外,其余病人肝功能无明显变化;药物副作用有高脂血症、贫血、溃疡型口疮等.结论 西罗莫司可以安全地应用于肝移植术后钙调素类免疫抑制剂相关肾功能损害的病人,改善病人的肾功能,同时对移植肝功能无明显影响.     

Measuring vs estimating glomerular filtration rate in kidney transplantation

Evaluation of kidney function is crucial in the care of kidney transplant recipients and in the design and interpretation of clinical trials in transplantation. Kidney function is most commonly assessed in both instances using serum creatinine concentration or an estimate of glomerular filtration rate (GFR) based on serum creatinine. These are inexpensive, widely available, and easily administered. Both have significant drawbacks, notably with respect to their inability to accurately identify changes in GFR. Novel markers of GFR such as cystatin C and β-trace protein show promise as accurate and sensitive markers of GFR but have not yet been adequately evaluated in kidney transplantation. In addition, they are relatively expensive compared to creatinine and their assays are not available in most clinical laboratories. Glomerular filtration rate measurement using a variety of different available tracers and techniques is infrequently used in either clinical care or research protocols because of its cost and cumbersomeness. This review will discuss the merits and pitfalls of the various tools available to evaluate GFR in kidney transplantation.     

The stability of the glomerular filtration rate after renal transplantation is improving

The 6-mo function and the stability of function posttransplantation in 429 cadaver renal transplants was investigated from 1990 to 2000. The 6-mo creatinine clearance (CrCl) and the rate of change of CrCl beyond 6 mo posttransplantation were calculated. The mean 6-mo CrCl was 64.6 +/- 1.1 ml/min and was stable between 1990 and 2000. The net slope of CrCl was -1.4 +/- 0.5 ml/min per yr. The slope has improved in recent years, such that the mean slopes in the period after 1997 are actually positive (+3.5 ml/min per yr). The slope of CrCl beyond 6 mo was not related to the actual value of the 6 mo CrCl, i.e., there was no accelerated loss of function at low CrCl levels. The 6-mo CrCl was independently determined by donor factors (age, gender), recipient factors (age, gender), and immune factors (rejection episodes, regraft status). The slope of the CrCl correlated independently with the transplant year, recipient gender, rejection episodes, diastolic BP, and the choice of immunosuppressive drugs. Cytomegalovirus infection and mismatch status and lipid levels and treatment were not independently associated with slope or 6-mo CrCl. Thus, the most striking change in the course of renal transplants over the past decade is the new stability of function, correlating with reduced rejection and probably due at least in part to the new immunosuppressive agents. Despite continued calcineurin inhibitor use, late improvement in function now occurs in many cadaver kidney transplants, suggesting a previously unappreciated capacity for functional adaptation.     

Erythropoietin administration is associated with short-term improvement in glomerular filtration rate after ischemia-reperfusion injury

Background: Erythropoietin (EPO) is a cytokine with organ‐protective properties. We hypothesized that EPO could attenuate acute renal dysfunction and inflammation in a porcine model of ischemia–reperfusion (IR). Furthermore, we aimed to characterize the impact of EPO on systemic and renal hemodynamics, and renal oxygen consumption. Methods: Twenty‐four pigs were randomly assigned to three groups: (1) EPO (5000 IU/kg) administered intravenously before IR (n=9), (2) placebo administered before IR (n=9), or (3) sham group, anesthetized and operated on only (n=6). IR was induced by clamping the left renal artery for 45 min. Hemodynamics and renal blood flow (RBF) were analyzed continuously. Glomerular filtration rate (GFR), renal oxygen consumption, and plasma cytokines (IL‐1β, IL‐6, IL‐8, IL‐10, and TNF‐α) were analyzed hourly. Renal biopsies were analyzed for cytokine content and apoptosis. Results: GFR was higher during reperfusion in the EPO group than in the placebo group (P<0.01). No differences between the IR groups were found in hemodynamics, RBF, oxygen consumption, or renal apoptosis. The levels of TNF‐α in the plasma (P=0.036) and the levels of TNF‐α and IL‐10 in the renal cortex (P=0.04 and P=0.01, respectively) were lower in the EPO group compared with the sham group. Conclusion: EPO attenuated the renal dysfunction as estimated as GFR. This effect was not related to changes in the hemodynamics. The immunomodulatory effects of EPO were manifested as decreased levels of TNF‐α and IL‐10 in renal biopsies and TNF‐α levels in plasma.     

Sirolimus and mycophenolate mofetil after liver transplantation

Since the approval of sirolimus (SRL) as an immunosuppressive agent in renal transplantation, several liver transplant centres have introduced this agent to the immunosuppression regimen. We present here a retrospective follow-up study of late conversion to sirolimus and mycophenolate mofetil (MMF) as immunosuppressive agents after liver transplantation (LTX). From July 2001 to March 2002, seven liver transplant recipients (three female, 59 (41-66) years old) were enrolled in this study. Indications for liver transplantation were hepatitis B and/or hepatitis C (three), alcohol-induced cirrhosis (three) and Wilson's syndrome (hepatolenticular degeneration) (one). LTX was performed by standard (four) or piggy-back (three) technique. The switch to SRL was performed 62 (37-118) months after LTX; the reasons for the switch from cyclosporine or tacrolimus to SRL were renal (six) or neurological (one) impairment. As immunosuppressive therapy, SRL at trough levels of 4-10 ng/ml and MMF at trough levels of approximately 1 micro g/ml were administered. Mean follow-up time under SRL per patient was 137 (26-258 days). Patient and graft survival was 100% during SRL therapy, and there were neither rejection episodes nor infections. Renal function improved in five of the six patients (83.3%) whom we had switched to SRL due to renal impairment. In the patient whom we switched to SRL due to neurological impairment, the neurological symptoms abated, and renal function improved. Side effects (hypertriglyceridaemia, hypercholesterolaemia, exanthema) became manifest in three patients (42.8%). Cessation of therapy due to side effects was necessary in two patients (exanthema: one, hypertriglyceridaemia: one). One patient refused to continue the therapy with SRL because he wanted tablets, and we only had SRL in fluid form. The data of our study suggest that SRL is a potent immunosuppressive agent of potential benefit in clinical LTX. SRL in combination with MMF provided sufficient immunosuppression of liver allografts in the late course after LTX. Side effects were reversible with dose reduction or cessation of therapy. We can thus conclude that SRL might offer an immunosuppressive therapy for patients with renal or neurological impairment after LTX.     

Serial decrease in glomerular filtration rate in long-term pediatric liver transplantation survivors treated with cyclosporine

Serial calculations of glomerular filtration rate were made in 31 pediatric liver transplant recipients surviving more than 1 year. GFR was computed from the Schwartz formula, (cGFR = KL/S Cr), before orthotopic liver transplantation, and at 3-6 monthly intervals thereafter. At the same time points, CsA dose/kg, CsA level, blood pressure, and liver functions were recorded. The mean difference between the pre-OLT cGFR and the most-current cGFR for all patients was -50 ml/min/1.73 m2 (P = less than 0.005). In 17/31 (55%), the current cGFR was less than 80 ml/min/1.73 m2, indicative of renal impairment. The cGFR continued to decrease in 24 patients followed beyond 1 year (26.8 ml/min/1.73 m2 per year decrease, P less than 0.005). More patients with a cGFR less than 80 ml/min/1.73 m2 had outpatient hypertension. There was no correlation of cGFR with CsA levels, CsA dose, or liver function. We conclude that a significant decrease in cGFR is seen in children treated with CsA for more than 1 year, which is progressive in the majority.     

Factors influencing glomerular filtration rate in renal transplantation after cyclosporine withdrawal using sirolimus-based therapy: a multivariate analysis of results at five years

Changes in calculated glomerular filtration rate (GFR) from baseline to five yr were analyzed in relation to risk factors among renal transplant recipients. At three months after transplantation (baseline), 430 eligible patients receiving sirolimus (SRL), cyclosporine (CsA), and steroids (ST) were randomly assigned (1:1) to continue SRL-CsA-ST or have CsA withdrawn and SRL trough levels increased (SRL-ST group). For each risk factor, changes from baseline were compared within each treatment using a t-test and between treatments using ANCOVA. Univariate then multivariate robust linear regression analyses were also performed. In the SRL-ST group, changes from baseline were not significantly different for any risk factor. With the exception of cold ischemia time >24 h, GFR values declined significantly for all risk factors in SRL-CsA-ST patients. For all risk factors, except second transplant or cold ischemia time >24 h, renal function was significantly different between groups. By order of significance in the multivariate analysis, treatment (p < 0.001), donor age (p < 0.001), proteinuria (p < 0.001), and biopsy-confirmed rejection (p = 0.010) were significant predictors of GFR change from baseline. In conclusion, patients with risk factors for reduced renal function benefit from SRL maintenance therapy without CsA vs. those remaining on CsA.     

Course of glomerular filtration rate after renal transplantation and the influence of hypertension.

INTRODUCTION: A gradual decline in the glomerular filtration rate (GFR) is a general problem in patients after renal transplantation that may be due to several factors. METHODS: The glomerular filtration rate (GFR) was estimated using the corrected Schwartz formula in 16 pediatric renal transplant recipients over a period of 5 years post-transplant. Several potential risk factors for graft outcome were analyzed. The mean age of the patients (8 female, 8 male) at the time of transplantation was 11.1 years (range: 2.7-17.3). All patients received a cadaveric renal graft for the first time. Immunosuppression consisted of cyclosporine in combination with steroids in all children treated; 3 patients received azathioprine in addition. Blood pressure (BP) was monitored regularly and its extent was expressed by an antihypertensive treatment (AHT) score. RESULTS: At the end of the first post-transplant year the mean GFR was 88 +/- 24 ml/min/1.73 m2. During the following 4 years the GFR declined to 68 +/- 29 ml/min/1.73 m2 representing an overall GFR loss of 20 ml/min/1.73 m2 (23%). With regard to the GFR loss, 2 groups could be distinguished. The first group of 7 patients showed a significant GFR decrease from 89 +/- 26 to 49 +/- 27 ml/min/1.73 m2 (p = 0.0025), whereas the second group of 9 patients had a relatively constant GFR during the 5 years (87 +/- 26 and 83 +/- 24 ml/min/1.73 m2). In each group, two acute rejections were observed in the first post-transplant year. Blood pressure, expressed by an AHT score, increased in Group 1 moresso than in Group 2 during the 5 years. CONCLUSION: During the course of a 5-year period post-transplant the GFR declined significantly in 7 of 16 patients. One of the factors responsible for GFR loss is probably the increase in blood pressure.     

Glomerular filtration rate after liver transplantation with a low-dose cyclosporin protocol

Cyclosporin nephrotoxicity is a well-known complication in organ transplantation. In successful liver transplantation, a moderate degree of renal impairment is accepted. Whether this impairment is continuously progressive, stabilizes with time, or is reversible is not known. We have prospectively evaluated the glomerular filtration rate (GFR) using ⁵¹CrEDTA plasma clearance in 29 liver transplant patients (11 males and 18 females) with a mean age of 49 years (range 22–62 years). The ⁵¹CrEDTA plasma clearance measurements were performed preoperatively and at 3, 6, 12, 24, and 36 months after the liver transplantation. All but six patients were given sequential, quadruple drug therapy with antithymocyte globulin, azathioprine, steroids, and cyclosporin. Intravenous cyclosporin was avoided and oral cyclosporin started when renal function was stable. Cyclosporin was started in a dose of 8 mg/kg body weight, aiming at whole blood trough levels (specific monoclonal technique) of 200 g/l in the postoperative period; thereafter, the dosage was rapidly tapered down, aiming at whole blood trough levels of less than 100 g/l at 3 months (1.5–2 mg/kg body weight). From a mean preoperative GFR of 89±3 ml/min per 1.73 m², all patients declined in renal function after transplantation to a mean of 64±4 ml/min per 1.73 m² 3 months after transplantation, and starting in the 3rd month the renal function was stable at about 70% of the preoperative value. No correlations were found between cyclosporin weak level or accumulated cyclosporin dose and renal impairment. We conclude that liver transplantation with cyclosporin immunosuppression will induce renal impairment even if cyclosporin blood levels are carefully monitored and kept low. However, with a low-dose regimen, a progressive decline can be avoided.     

Sirolimus monotherapy in liver transplantation

INTRODUCTION: Since 1999, a new immunosuppressive drug was administered to renal transplant patients. The SRL molecule acts by blocking post-receptor signal transduction of interleukin-2 (IL-2) interacting with a family of intracellular binding proteins termed immunophilins FKBPs. Among these FKBPs, FK506 12-kd binding protein is the most relevant. SRL is an immunosuppressive drug. Therefore it can inhibit the immune system; at the same time the drug is not nephrotoxic, neurotoxic, and without diabetogenic effects. METHODS: Among 285 patients who underwent liver transplantation, 27 took Sirolimus as monotherapy. Immunosuppressive treatment upto cyclosporine (CsA) or tacrolimus (FK) associated with steroids (methylprednisolone) and mycophenolate Mofetil (MMF) was initiated among subjects with pre-transplant renal failure. SRL was administered as monotherapy for patients who developed nephrotoxicity, or neurotoxicity, or diabetes. Moreover, patients affected by multifocal HCC who did not meet the Milan criteria or patients who developed Kaposi's Sarcoma were prescribed SRL monotherapy. RESULTS: Nephrotoxicity occurred in 14 patients with mean serum creatinine level 2.2 mg/dl. Eleven patients with real failure showed significant improvements after a mean period of 28 days of SRL monotherapy (range: 6-45 days). The mean creatinine serum level after treatment with SRL monotherapy was 1.0 mg/dl (range: 0.7-1.2 mg/dl). Neurotoxicity occurred in 4 patients with tremor, confusion, and agitation. Each patient had complete improvement of symptoms after a few days of Sirolimus monotherapy. Among Three patients who developed Kaposi's Sarcoma, two underwent remission. One patient had diabetes due to calcineurin inhibitors, and one showed arterial hypertension not treatable with drugs. After the switch, we treated these patients with medications. Another important indication was HCC not meeting the Milan criteria. CONCLUSION: SRL monotherapy may be used to manage complication of calcineurin inhibitors or Kaposi's Sarcoma.