Successful withdrawal of steroids in pediatric renal transplant recipients receiving cyclosporine A and mycophenolate mofetil treatment: results after four years

Steroid avoidance/withdrawal and maintenance immunosuppression in pediatric kidney transplantation

BACKGROUND

Corticosteroids have been an integral part of maintenance immunosuppression for pediatric kidney transplantation. However, prolonged steroid therapy is associated with significant toxicities resulting in several SW/avoidance strategies in recent years.

METHOD/OBJECTIVE

This comprehensive review aims to discuss steroid-related toxicities and the safety, efficacy, and benefit of steroid avoidance/withdrawal immunosuppression in pediatric kidney transplant recipients.

RESULTS

Initial studies of SW/avoidance conducted in the setting of CSA and AZA showed an increased incidence of AR but no increase in graft loss or mortality with SW/avoidance maintenance immunosuppression. Studies performed under modern immunosuppression (induction therapy, Tac, and MMF) show no significant increase in AR or graft loss with SW/avoidance immunosuppression. Furthermore, SW/avoidance immunosuppression is associated with significant improvement in growth, BMI, BP control, and lipid profile in pediatric kidney transplant recipients. Despite these data, SW/avoidance remains controversial, and only 40% of pediatric kidney transplant recipients in the United States are currently on SW/avoidance maintenance immunosuppression.

CONCLUSION

SW/avoidance maintenance immunosuppression is safe and associated with fewer side effects compared with steroid-inclusive maintenance immunosuppression in pediatric kidney transplant recipients.

Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients

Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.

Changes in body mass index after pediatric renal transplantation

Significant weight gain following renal transplantation is common in adult and pediatric recipients and mostly depends on receiving higher doses of steroids, changes in mood and feelings, as well as their level of physical activities. This study was performed to evaluate body weight and body mass index (BMI) before and after kidney transplantation in children and adolescents. In this cross-sectional study, 71 pediatric renal transplant recipients (42 boys and 29 girls) were included. World Health Organization criteria were used for comparing Z-score BMI for age in our cases. Overweight was defined as Z-score BMI >+1 SD (standard deviation) and obesity as >+2 SD. At the time of transplantation, the mean age was 10.8 ± 3 years (5-16 years) and based on BMIZ-score, the patients were found to be thin (BMIZs <-2 SD) in 16.9%, normal (BMIZs = -2 to +1 SD) in 67.6%, overweight (>+1 SD to +2 SD) in 9.9%, and obese (BMIZs >+2 SD) in 5.6%.The mean follow-up duration after transplantation was 3.57 ± 1.68 years (1-7 years) and at the time of reevaluation after transplant, their mean age was 14.4 years (6-18 years). The mean BMI was 22 ± 5.3 kg/m², and for BMI grouping, the patients were thin in 7%, normal in 54.9%, overweight in 21.1%, and obese in 17%. Pretransplant thinness (BMIZs <-2 SD) was found in 12 patients (16.9%), equally in boys and girls, and in most of them (83.3%), BMIZs changed to normal or even >+1 SD after transplant. Chronic continuous decrease of glomerular filtration rate (CCD/GFR) was found in 27 cases (38%); 74.1% were male (P = 0.045), hypertriglyceridemia was found in 74.1% (P = 0.023%), hypercholesterolemia in 63% (P = 0.032),and obesity in 18.5% (p = 0.5). The incidence of obesity has tripled after kidney transplantation. It was not a risk factor for graft or patient survival in our experience, whereas pretransplant obesity had some effects on long-term graft outcome.

Corticosteroid Use and Growth After Pediatric Solid Organ Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

A number of corticosteroid minimization and avoidance protocols for post-solid organ transplant have been developed. The study objective was to examine the effect of corticosteroid withdrawal/avoidance on growth and safety parameters in pediatric solid organ transplant recipients.

METHODS

A systematic review using Medline and Embase was performed. All randomized controlled trials (RCT) and observational studies comparing corticosteroid withdrawal/avoidance to controls receiving corticosteroids in pediatric transplant recipients which reported growth as change in height or final height were included. Two reviewers independently abstracted study data and assessed quality.

RESULTS

The search yielded 930 records, 14 separate studies involving 1146 patients. Renal RCTs (n = 5) showed that corticosteroid withdrawal/avoidance was associated with a significant increase in growth (mean difference in height standard deviation score [SDS], 0.18; 95% confidence interval [95% CI], 0.07-0.29; P = 0.001) compared with those remaining on steroids. In liver RCTs (n = 2), mean difference in height SDS was -0.20 (95% CI, -1.08 to 0.68; P = 0.66). Results for renal observational studies (n = 5) was 0.34 (95% CI, 0.03-0.65; P = 0.03). The most pronounced effect was seen in prepubertal children with SDS of 0.28 (95% CI, 0.14-0.41; P < 0.0001). In pubertal participants this was not observed (SDS, 0.06; 95% CI, -0.04 to 0.15; P = 0.24). Corticosteroid withdrawal/avoidance was not associated with acute rejection (odds ratio [OR], 0.87; P = 0.63), graft failure (OR, 0.45; P = 0.08), or death (OR, 0.34; P = 0.16) in renal trials.

CONCLUSIONS

Corticosteroid withdrawal/avoidance in pediatric renal transplantation is associated with a significant improvement in height. Prepubertal patients appeared to have the greatest benefit. Importantly, the improvement in growth was not accompanied by increased rejection or worsening patient/allograft survival in the short term.

Corticosteroid-free Kidney Transplantation Improves Growth: 2-Year Follow-up of the TWIST Randomized Controlled Trial

BACKGROUND

Corticosteroid withdrawal (CW) after pediatric kidney transplantation potentially improves growth while avoiding metabolic and other adverse events. We have recently reported the results of a 196 subject randomized controlled trial comparing early CW (tacrolimus, mycophenolate mofetil (MMF), daclizumab, and corticosteroids until day 4) with tacrolimus, MMF, and corticosteroid continuation (CC). At 6 months, CW subjects showed better growth with no adverse impact on acute rejection or graft survival (Am J Transplant 2010; 10: 828-836). This 2-year investigator-driven follow-up study aimed to determine whether improved growth persisted in the longer term.

METHODS

Data regarding growth, graft outcomes and adverse events were collected at 1 year (113 patients) and 2 years (106 patients) after transplantation. The primary endpoint, longitudinal growth calculated as delta height standard deviation score, was analyzed using a mixed model repeated measures model.

RESULTS

Corticosteroid withdrawal subjects grew better at 1 year (difference in adjusted mean change, 0.25; 95% confidence interval, 0.10, 0.40; P = 0.001). At 2 years, growth remained numerically better in CW subjects (0.20 (-0.01, 0.41); P = 0.06), and significantly better in prepubertal subjects (0.50 (0.16, 0.84); P = 0.004). Bacterial and viral infection was significantly more common in CW subjects at 1 year only. Corticosteroid withdrawal and CC subjects received similar exposure to both tacrolimus and MMF at 1 and 2 years. No significant difference in patient or graft survival, rejection, estimated glomerular filtration rate, or other adverse events was detected.

CONCLUSION

Early CW effectively and safely improves growth up to 2 years after transplantation, particularly in prepubertal children.

Growth hormone, insulin-like growth factor-1, and the kidney: pathophysiological and clinical implications

Besides their growth-promoting properties, GH and IGF-1 regulate a broad spectrum of biological functions in several organs, including the kidney. This review focuses on the renal actions of GH and IGF-1, taking into account major advances in renal physiology and hormone biology made over the last 20 years, allowing us to move our understanding of GH/IGF-1 regulation of renal functions from a cellular to a molecular level. The main purpose of this review was to analyze how GH and IGF-1 regulate renal development, glomerular functions, and tubular handling of sodium, calcium, phosphate, and glucose. Whenever possible, the relative contributions, the nephronic topology, and the underlying molecular mechanisms of GH and IGF-1 actions were addressed. Beyond the physiological aspects of GH/IGF-1 action on the kidney, the review describes the impact of GH excess and deficiency on renal architecture and functions. It reports in particular new insights into the pathophysiological mechanism of body fluid retention and of changes in phospho-calcium metabolism in acromegaly as well as of the reciprocal changes in sodium, calcium, and phosphate homeostasis observed in GH deficiency. The second aim of this review was to analyze how the GH/IGF-1 axis contributes to major renal diseases such as diabetic nephropathy, renal failure, renal carcinoma, and polycystic renal disease. It summarizes the consequences of chronic renal failure and glucocorticoid therapy after renal transplantation on GH secretion and action and questions the interest of GH therapy in these conditions.

Surgical complications and graft survival in pediatric kidney transplant recipients treated with a steroid-free protocol: experiences from a Danish university hospital

BACKGROUND

The outcome of pediatric kidney transplantation depends on several factors, among these are the complications, which occur in relation to the surgical procedure. In this study, we present our experience with pediatric kidney transplantation in a steroid-free immunosuppression regimen, from a surgical point of view.

METHODS

Patient charts of pediatric kidney transplantations in the period 1998-2011 were reviewed. Surgical complications, acute rejection, and patient and graft survivals were recorded.

RESULTS

Sixty-one renal transplantations were performed in 58 patients. Thirty patients (49.1%) experienced a surgical complication, of which 11 (18%) required an explorative laparotomy. Overall the five-year Kaplan-Meier patient survival rate was 96.2% and the graft survival rate was 88.6%. Nine patients (14.7%) had an acute rejection episode within the first year after transplantation. No correlation was observed between surgical complications and acute rejection episodes or graft loss.

CONCLUSIONS

This study indicated a high incidence of surgical complications among pediatric kidney transplantations when using a steroid-free immunosuppression regimen. Despite this, we observed high overall patient and graft survival, supporting the trend toward steroids avoidance in pediatric kidney transplantation.

Steroid withdrawal in renal transplantation

Over the last decade, steroid minimization became one of the major goals in pediatric renal transplantation. Different protocols have been used by individual centers and multicenter study groups, including early and late steroid withdrawal or even complete avoidance. The timing of steroid withdrawal determines if antibodies are used, as avoidance and early withdrawal require antibody induction, while late withdrawal typically does not. A monoclonal antibody was used in most protocols during an early steroid withdrawal together with tacrolimus and mycophenolate mofetil in low immunological risk patients. Polyclonal induction was reported as effective in high-risk patients. Cyclosporine A and mycophenolate mofetil were used in late steroid withdrawal with no induction. All described protocols were effective in terms of preventing acute rejection and preserving renal graft function. There was no superiority of any specific protocol in terms of clinical benefits of steroid withdrawal. Pre-puberty determined growth benefit while other clinical advantages, including better control of glycemia, lipids, and blood pressure, were age independent. It is not clear whether the steroid withdrawal increases the risk of recurrence of primary glomerular diseases post-transplant, however it cannot be excluded. There is no evidence to date for a higher risk of anti-HLA production in steroid-free children after renal transplantation. Key summary points--Current strategies to minimize the steroid-related adverse effects in pediatric renal graft recipients include steroid withdrawal, early or late after transplantation, or complete steroid avoidance--Early steroid withdrawal or avoidance is generally used following the induction therapy with mono- or polyclonal antibodies, while in late steroid withdrawal induction therapy was generally not used- Elimination of steroids (early or late) does not increase the risk of acute rejection and does not deteriorate long-term renal graft function- Early steroid withdrawal is possible in patients at high immunological risk using a combination of polyclonal antibody induction, tacrolimus, and mycophenolate mofetil- All protocols of steroid minimization showed relevant clinical benefits, however the growth-related benefit was limited to pre-pubertal patients in all but one of the studies- Adverse events of steroid withdrawal occurred in a higher incidence of post-transplant bone marrow suppression Key research points - There is no clear evidence of the impact of steroid withdrawal on the risk of recurrence of primary glomerulonephritis after renal transplantation in children, therefore further evaluation of this important issue should be performed in prospective trials- There is limited pediatric data on the risk of anti-HLA/donor-specific antibody production in steroid-free patients after renal transplantation. It is not clear whether the selection of the type of induction antibody (lymphocyte depleting versus short, two-dose administration of anti-IL2R inhibitor) is important in this term. The production of anti-HLA antibodies should then be monitored on a regular basis and analyzed in prospective trials.

Complete steroid avoidance is effective and safe in children with renal transplants: a multicenter randomized trial with three-year follow-up

To determine whether steroid avoidance in pediatric kidney transplantation is safe and efficacious, a randomized, multicenter trial was performed in 12 pediatric kidney transplant centers. One hundred thirty children receiving primary kidney transplants were randomized to steroid-free (SF) or steroid-based (SB) immunosuppression, with concomitant tacrolimus, mycophenolate and standard dose daclizumab (SB group) or extended dose daclizumab (SF group). Follow-up was 3 years posttransplant. Standardized height Z-score change after 3 years follow-up was -0.99 ± 2.20 in SF versus -0.93 ± 1.11 in SB; p = 0.825. In subgroup analysis, recipients under 5 years of age showed improved linear growth with SF compared to SB treatment (change in standardized height Z-score at 3 years -0.43 ± 1.15 vs. -1.07 ± 1.14; p = 0.019). There were no differences in the rates of biopsy-proven acute rejection at 3 years after transplantation (16.7% in SF vs. 17.1% in SB; p = 0.94). Patient survival was 100% in both arms; graft survival was 95% in the SF and 90% in the SB arms (p = 0.30) at 3 years follow-up. Over the 3 year follow-up period, the SF group showed lower systolic BP (p = 0.017) and lower cholesterol levels (p = 0.034). In conclusion, complete steroid avoidance is safe and effective in unsensitized children receiving primary kidney transplants.

Effects of steroid avoidance and novel protocols on growth in paediatric renal transplant patients

The vast majority of kidney transplant recipients undergo triple maintenance immunosuppression that includes the use of steroids. Irrespective of their long history in organ transplantation and proven efficacy in preventing acute graft rejection, steroids exhibit an unfavourable toxicity profile, including growth retardation in children. Given these negative effects, therapeutic approaches that will substantially decrease patients' exposure to steroids have been considered. The planned approaches included alternate day administration, rapid or late steroid withdrawal at the pre-scheduled time after transplantation and complete steroid avoidance. All three of these strategies have been tested in single- or multicentre studies and shown to have distinct clinical advantages in terms of decreasing the incidence and severity of specific adverse events. However, the safety of these protocols could not be universally proven. The Stanford study showed that a complete steroid avoidance under the "cover" of tacrolimus, mycophenolate mofetil and extended daclizumab induction is a very effective regimen for obtaining an improvement in post-transplantation growth. The recently reported international randomized TWIST trial demonstrated growth improvement as early as 6 months post-transplantation. These protocols may potentially enable paediatric renal graft recipients to safely avoid steroid exposure.

A randomized trial to assess the impact of early steroid withdrawal on growth in pediatric renal transplantation: the TWIST study

Minimizing steroid exposure in pediatric renal transplant recipients can improve linear growth and reduce metabolic disorders. This randomized multicenter study investigated the impact of early steroid withdrawal on mean change in height standard deviation score (SDS) and the safety and efficacy of two immunosuppressive regimens during the first 6 months after transplantation. Children received tacrolimus, MMF, two doses of daclizumab and steroids until day 4 (TAC/MMF/DAC, n=98) or tacrolimus, MMF and standard-dose steroids (TAC/MMF/STR, n=98). Mean change in height SDS was 0.16 +/- 0.32 with TAC/MMF/DAC and 0.03 +/- 0.32 with TAC/MMF/STR. The mean treatment group difference was 0.13 (p < 0.005 [95% CI 0.04-0.22]), 0.21 in prepubertal (p = 0.009 [95% CI 0.05-0.36]) and 0.05 in pubertal children (p = ns). Frequency of biopsy-proven acute rejection was 10.2%, TAC/MMF/DAC, and 7.1%, TAC/MMF/STR. Patient and graft survival and renal function were similar. Significantly greater reductions in total cholesterol and triglycerides but significantly higher incidences of infection and anemia were found with TAC/MMF/DAC (p < 0.05 all comparisons). Early steroid withdrawal significantly aided growth at 6 months more so in prepubertal than pubertal children. This was accompanied by significantly better lipid and glucose metabolism profiles without increases in graft rejection or loss.

A study on strategies for improving growth and body composition after renal transplantation

Allograft function and metabolic effects of four treatment regimens, namely, methylprednisone (MP) standard dose (MP-STD), deflazacort (DFZ), MP-late steroid withdrawal (MP-LSW), and MP-very low dose (MP-VLD), were evaluated in prepubertal patients. MP was decreased by month 4 post-transplantation to 0.2 mg/kg/day in MP-STD and DFZ patients and to <0.1 mg/kg/day in MP-LSW and MP-VLD patients. Starting in month 16 post-transplant, MP was switched to DFZ in the DFZ group and totally withdrawn in the MP-LSW group. Creatinine clearance diminished in the MP-STD and MP-LSW groups from 77 +/- 6 to 63 +/- 6 ml/min/1.73 m(2)and from 103 +/- 5 to 78 +/- 3 ml/min/1.73 m(2), respectively (p < 0.01 and p < 0.001, respectively). Height increased >0.5 SDS only in the MP-LSW and MP-VLD groups. The body mass index and fat body mass for height-age increased only in the MP-STD patients (p < 0.05 and p < 0.01, respectively). Fat body mass decreased in the DFZ group (p < 0.05), total cholesterol and LDL-cholesterol increased in the MP-STD group, while LDL-cholesterol and total cholesterol/HDL-cholesterol ratio decreased in the DFZ group (p < 0.01). Lumbar spine bone mineral density (BMD) for height-age showed an increase in the MP-LSW and MP-VLD groups (p < 0.01). Our data suggest that MP-LSW and MP-VLD strategies improve linear growth, BMD, the peripheral distribution of fat, and preservation of the bone-muscle unit and maintain the normal lipid profile. The MP-LSW patients had a concerning rate of acute rejections and graft function deterioration in prepubertal patients.

Pediatric renal transplantation: an overview and update

PURPOSE OF REVIEW

Transplantation is the preferred method of treatment for end-stage renal disease in children. The rate of pediatric kidney transplantation has been steadily rising over the past decade. The use of increasingly potent immunosuppressive drugs has lessened the risk for acute rejection substantially and improved short-term outcomes; however, the long-term outcomes have remained inadequate.

RECENT FINDINGS

The follow-up of pediatric cohorts and the encouraging results from data registries prompt us to revisit our practices in transplantation so as to devise additional strategies to improve long-term outcomes.

SUMMARY

This review presents a comprehensive discussion of the major issues in pediatric renal transplantation, the newer immunosuppression approaches to limit toxicities of therapies in children and some critical issues that remain to be addressed, specific to the care of the transplanted child. The ultimate goal of designing optimum conditions for equating graft survival to patient survival still remains a major goal for pediatric organ transplantation.

Steroid avoidance using sirolimus and cyclosporine in pediatric renal transplantation: one year analysis

Steroids are commonly used in pediatric renal transplantation, but have numerous adverse effects. This retrospective study compares one-yr outcomes in 22 pediatric renal transplant recipients receiving SRL and CSA as primary immunosuppression (steroid-avoidance group) to age- and gender-matched historical controls receiving CSA, MMF, and prednisone (steroid group). At one yr, both groups had similar graft survival, acute rejection, and estimated GFR. Subjects in the steroid-avoidance group had better linear growth, less excessive weight gain and were less likely to have an increase in antihypertensive medication use. Subjects in the steroid-avoidance group were more likely to be started on lipid lowering medications and erythropoiesis stimulating agents. Despite having a greater proportion of living donors, the steroid-avoidance group had a similar GFR compared to the steroid group at one month. The steroid-avoidance group was also more likely to have a biopsy for elevated Cr that was not because of rejection and had more interstitial fibrosis noted. We conclude that using a steroid-avoidance immunosuppression regimen of SRL and CSA results in comparable rejection rates and short-term graft function with less steroid-associated morbidity. However, early findings also suggest possible potentiation of CSA nephrotoxicity by SRL in some children.

A randomized double-blind, placebo controlled trial of steroid withdrawal after pediatric renal transplantation

In an effort to reduce rejection, extend allograft survival and minimize complications, we hypothesized that robust immunosuppression during the first 6 months after transplantation would allow for the safe withdrawal of steroids. A total of 274 pediatric subjects were enrolled and received an anti-CD25 antibody, sirolimus, calcineurin inhibitor and steroids. At 6 months after transplantation, subjects were randomized to steroid withdrawal (n=73) versus continued low-dose steroids (n=59). This study was stopped prior to target enrollment because of the incidence of post-transplant lymphoproliferative disorder. At the time of study termination, 132 subjects had been randomized and were available for analysis. At 18 months after transplantation, there was no difference in the standardized height z score; however, the standardized height velocity was greater in the steroid withdrawal group compared to the control group (p=0.033). There were no differences in acute rejection episodes between treatment groups. The 3-year allograft survival rate was 84.5% in the control group and 98.6% in the steroid withdrawal group (p=0.002). The immunosuppressive protocol utilized in this study allowed for the withdrawal of steroids without an increased risk of rejection or allograft loss. However, the complications associated with the use of this immunosuppressive protocol were too high to recommend its routine use in pediatric patients.

Steroid-free immunosuppression in pediatric renal transplantation: rationale for and [corrected] outcomes following conversion to steroid based therapy

BACKGROUND

Short-term outcomes using steroid-free immunosuppression after renal transplantation have been promising. No studies have examined the incidence of and reasons for steroid-avoidance protocol failures.

METHODS

We present a single-center analysis of steroid-free immunosuppression failures among 129 pediatric renal transplant recipients with mean follow-up of 5 years. We analyzed causes for failure and examined reasons for conversion to steroid-based therapy. We compared actual patient and allograft survival and allograft function in the cohort of patients who required conversion to steroid-based immunosuppression with that of the cohort maintaining steroid-free immunosuppression.

RESULTS

A total of 13.2% (17/129) of patients failed steroid-free immunosuppression. Actual patient survival was equivalent in the two cohorts, 96.4% for the cohort maintaining steroid-free immunosuppression and 94.1% for those requiring conversion. Actual allograft survival was lower in patients requiring conversion to a steroid-based protocol, 76.5% vs. 95.5% (P=0.004). Estimated glomerular filtration rates 12-months and 24-months posttransplant were greater in patients maintaining steroid-free immunosuppression (P=0.003). Most patients (52.9%, 9/17) who broke the steroid-free protocol did so because of refractory acute rejection. The second most common reason was recurrence of glomerulonephritis (GN; 35.3%, 6/17).

CONCLUSION

The failure rate of steroid-free immunosuppression among selective pediatric patients undergoing renal transplantation is low. Patients maintaining steroid-free immunosuppression have better allograft survival and function than those requiring conversion to steroid-based therapy. The most common reasons for failure of steroid-free immunosuppression are recalcitrant or recurrent allograft rejection and recurrent GN; the role of conversion to steroid-based immunosuppression after episodes of acute rejection and recurrent GN requires additional analysis.

Growth after renal transplantation

Growth may be severely impaired in children with chronic renal insufficiency. Since short stature can have major consequences on quality of life and self-esteem, achieving a 'normal' height is a crucial issue for renal transplant recipients. However, despite successful renal transplantation, the final height attained by most recipients is not the calculated target height. Catch-up growth spurts post-transplantation are usually insufficient to compensate for the retardation in growth that has occurred during the pre-transplant period. Longitudinal growth post-transplantation is therefore influenced by the age at transplantation but also by subsequent allograft function and steroid exposure, both of which interfere with the growth hormone/insulin-like growth factor axis. The management of growth retardation in renal transplant recipients includes adequate nutritional intake, correction of metabolic acidosis, prevention of bone disease, steroid-sparing strategies and a supraphysiological dose of recombinant human growth hormone in selected cases.

Prospective, randomized trial on late steroid withdrawal in pediatric renal transplant recipients under cyclosporine microemulsion and mycophenolate mofetil

BACKGROUND

: Many transplant centers practice late steroid withdrawal after pediatric renal transplantation, but evidence-based data on the overall risk-to-benefit ratio in this patient population are lacking.

METHODS

: We therefore conducted the first prospective, randomized, open-label multicenter study to validate this strategy: 42 low-immunologic risk pediatric kidney allograft recipients, aged 10.3+/-4.3 years, on cyclosporine microemulsion, mycophenolate mofetil, and corticosteroids were randomly assigned, more than or equal to 1-year posttransplant, to continue steroids or to withdraw over 3 months. This report contains the 1-year results.

RESULTS

: In response to steroid withdrawal, patients experienced a significant catch-up growth with a mean standardized height gain of 0.3+/-0.1 standard deviation score (SDS) per year (P<0.05 vs. control), whereas mean height SDS in the control group did not change (0.0+/-0.1 SDS). Standardized body mass index declined significantly by 0.68+/-0.23 SDS after steroid withdrawal, but rose significantly by 0.26+/-0.34 SDS in the control group. Patients off steroids had less frequent arterial hypertension (50% vs. 87.5% (P<0.05) and significantly lower serum cholesterol (by 21%) and triglyceride values (by 36%) than control patients. Patient and graft survival were 100%. The incidence of acute rejection episodes in the steroid-withdrawal group was 1 of 23 (4%) compared with 1 of 19 (5%) in controls. Transplant function remained stable in both groups.

CONCLUSION

: Late steroid withdrawal in low-immunologic risk European pediatric kidney transplant recipients on cyclosporine microemulsion and mycophenolate mofetil is not associated with an increased rate of acute rejection episodes, enables catch-up growth and ameliorates cardiovascular risk factors.

Steroid avoidance or withdrawal for kidney transplant recipients

BACKGROUND

Steroid-sparing strategies have been attempted during the last two decades in order to avoid morbidity in kidney transplant recipients. Previous systematic reviews of steroid withdrawal after kidney transplantation have shown significant increases in acute rejection and an increase in graft failure rates. Steroid avoidance in kidney transplantation is increasingly attempted and the possible benefits or harms have never been a subject of a systematic review.

OBJECTIVES

To assess the safety and efficacy of steroid withdrawal or avoidance in patients receiving a kidney transplant.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE, references lists and abstracts from international transplantation society scientific meetings.

SELECTION CRITERIA

Randomised controlled studies (RCTs) of steroid avoidance or withdrawal were included providing that one treatment arm consisted in steroid avoidance or withdrawal and intention-to-treat rates of acute rejection and graft failure were clearly established after steroid avoidance or use or withdrawal or continuation. Observational studies were tabulated.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and results expressed as risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 30 RCTs (5949 participants). Steroid-sparing strategies showed no effect on mortality or graft loss including death. Patients on any steroid-sparing strategy showed a higher risk of graft loss excluding death than those with conventional steroid use (RR 1.23, 95% CI 1.00 to 1.52), especially in those not receiving MMF/Myf or everolimus (RR 1.70, 95% CI 1.00 to 2.90). Acute rejection was more frequent with a steroid-sparing strategy (RR 1.27, 95% CI 1.14 to 1.40) and more frequent after steroid withdrawal or avoidance when compared with standard steroid treatment when cyclosporin (CsA) was used. Steroid-sparing and withdrawal strategies showed benefits in reducing antihypertensive drug need, serum cholesterol, antihyperlipidaemic drug need, new-onset diabetes after transplantation (NODAT) requiring any treatment and cataracts. Steroid avoidance did not alter serum cholesterol, but was associated with less frequent NODAT requiring any treatment. Cardiovascular events were reduced with steroid avoidance. Reduced antihypertensive drug need and serum cholesterol were similar with CsA or tacrolimus (TAC). Reduced antihyperlipidaemic drug need was only evident with TAC, whereas the reduction in NODAT requiring any treatment was only evident with CsA. Infection was lower in steroid-sparing patients using CsA (RR 0.88, 95% CI 0.78 to 1.00). NODAT requiring any treatment was less frequent with steroid avoidance than with steroid withdrawal.

AUTHORS' CONCLUSIONS

This review confirms that steroid avoidance and steroid withdrawal strategies in kidney transplantation are not associated with increased mortality or graft loss despite an increase in acute rejection. These immunosuppression strategies may allow safe steroid avoidance or elimination a few days after kidney transplantation if antibody induction treatment is prescribed or after three to six months if such induction is not used.

Hypertension after renal transplantation

Hypertension is a common and serious complication after renal transplantation. It is an important risk factor for graft loss and morbidity and mortality of transplanted children. The etiology of posttransplant hypertension is multifactorial: native kidneys, immunosuppressive therapy, renal-graft artery stenosis, and chronic allograft nephropathy are the most common causes. Blood pressure (BP) in transplanted children should be measured not only by casual BP (CBP) measurement but also regularly by ambulatory BP monitoring (ABPM). The prevalence of posttransplant hypertension ranges between 60% and 90% depending on the method of BP measurement and definition. Left ventricular hypertrophy is a frequent type of end-organ damage in hypertensive children after transplantation (50-80%). All classes of antihypertensive drugs can be used in the treatment of posttransplant hypertension. Hypertension control in transplanted children is poor; only 20-50% of treated children reach normal BP. The reason for this poor control seems to be inadequate antihypertensive therapy, which can be improved by increasing the number of antihypertensive drugs. Improved hypertension control leads to improved long-term graft and patient survival in adults. In children, there is a great potential for antihypertensive treatment that could also result in improved graft and patient survival.

Can pediatric steroid-free renal transplantation improve growth and metabolic complications?

We analyzed the effects of a steroid avoidance protocol in pediatric renal transplant recipients on calculated CrCl (Schwartz), CMV infection, cholesterol, height Z scores, weight Z scores, and BMI Z scores in a case control trial with contemporaneous controls. From 1999 to 2004, 19 pediatric patients (age 1-20 yr) received transplants without steroids using immunosuppression with tacrolimus, mycophenolate mofetil, and daclizumab. Control patients (n = 30) were matched for length of follow-up (minimum one yr), donor type age, type of immunosuppression, sex, date of transplant, and original disease, and CMV status. Graft survival at one year was 100% in both groups. Mean CrCl of steroid-free vs. control patients were not different at 1 year post-transplant. CMV disease was more prevalent in steroid-treated control group (seven of 30 patients) vs. the steroid free control group (zero of 19). Height delta Z scores at one year were NOT different between groups. Weight and BMI delta Z scores were significantly higher in the control group. Cholesterol levels at one year post-transplant were different in the two groups but NOT ABNORMALLY elevated in either group. At one yr post-transplant, steroid-free immunosuppression with tacrolimus, mycophenolate mofetil and daclizumab provides outcomes that are equivalent or superior to those in contemporaneous control patients receiving steroids.

Efficacy and safety of basiliximab in pediatric renal transplant patients receiving cyclosporine, mycophenolate mofetil, and steroids

BACKGROUND

Basiliximab, a monoclonal CD25 antibody has proofed effective in reducing acute rejection episodes in adults in various immunosuppressive regimens. The effect of basiliximab in the pediatric population is controversial.

METHODS

In a 12-month, double-blind, placebo-controlled trial, renal transplant patients aged 1 to 18 years were randomized to basiliximab or placebo with cyclosporine microemulsion, mycophenolate mofetil, and corticosteroids. The intent-to-treat population comprised 192 patients (100 basiliximab and 92 placebo).

RESULTS

The primary efficacy endpoint, time to first biopsy-proven acute rejection episode, or treatment failure by month 6, occurred in 16.7% of basiliximab-treated patients and 21.7% of placebo-treated patients (Kaplan-Meier estimates; hazard ratio 0.72, two-sided 90% confidence interval 0.416-1.26, n.s.). The rate and severity of subclinical rejections in protocol biopsies performed at 6 months posttransplant was higher in the basiliximab group (25.0%) than in the placebo group (11.7%). Patient and death-censored graft survival at 12 months was 97% and 99%, respectively, in the basiliximab cohort, and 100% and 99% among placebo-treated patients (n.s.). Renal function was similar in both treatment groups, and there were no significant between-treatment differences in the incidence of adverse events or infections.

CONCLUSIONS

Addition of basiliximab induction to a regimen of cyclosporine microemulsion, mycophenolate mofetil, and steroids resulted in a numerically lower but not significant incidence of biopsy-proven acute rejection versus placebo and excellent graft and patient survival at 1 year in pediatric renal transplant recipients. Whether this numerical difference is a true therapeutic benefit in view of the higher rate and severity of subclinical rejections in the basiliximab group in the protocol biopsy will be investigated in a long-term follow-up study.

Outcome after renal transplantation. Part II: quality of life and psychosocial adjustment

Knowledge of health-related quality of life (QOL) and psychosocial adjustment (PA) in children after renal transplantation (RTPL) is limited. QOL and PA were evaluated by standardized tests in patients after RTPL. Thirty-seven children of median age 14.5 years (range 6.5-17 years) were investigated a mean 4.5 years (range 0.5-12.8 years) after RTPL. Child- and parent-rated QOL was evaluated with the Child Quality of life Questionnaire of The Netherlands Organization for Applied Scientific Research Academical Medical Centre (TNO-AZL). PA was assessed by the Child Behaviour Checklist (CBCL) providing parental reports of a child's behaviour. In patients' self-ratings, the QOL dimension physical complaints (P < 0.0005) scored significantly better than that of healthy controls, whereas the dimension positive emotional functioning was impaired (P = 0.02). Parents rated motor functioning (P = 0.002), autonomy (P = 0.01), cognition (P = 0.04) and positive emotions (P < 0.0005) as significantly impaired. Parents also assessed PA significantly (P = 0.02) impaired with regard to internalizing behaviour. Dialysis duration, young age at RTPL, living-related donation, steroid treatment, adverse family relationships and maternal distress had a significantly negative impact on QOL and PA (P < 0.05). Patients rated QOL higher than did healthy controls. Parents evaluated their children's QOL and PA more pessimistically than did the patients themselves. Both illness-related variables and family environment played an important role.

Growth and weight gain of prepubertal children after cardiac transplantation

This study evaluated changes in growth parameters after pediatric heart transplantation and identified factors associated with the changes after pediatric heart transplantation (OHT). We retrospectively evaluated the somatic growth of 46 children <11 yr of age who underwent OHT for changes in weight, height, and BMI. The patient age range was 3.5 months to 10.7 yr. Gain in Z score for weight and BMI was significant at six months post-OHT (mean weight Z score changed from -1.1 to -0.1 and mean BMI Z score changed from -0.1 to 1.3; p < 0.001). After six months post-OHT, there was no further significant change in weight or BMI Z score. Height Z score did not show significant change from pre-OHT at six months, one yr, or two yr post-OHT. Eight patients (17%) became overweight during the two-yr follow-up period as evidenced by a BMI Z score > 2. Multivariate analysis showed length of steroid treatment as a predictor for negative height Z score change, and age at transplant as a predictor for positive height Z score change. Post-OHT, weight significantly increases without proportional increases in height, resulting in a significant proportion of these children becoming obese. Length of steroid therapy is negatively related to the "catch-up" linear growth following OHT.

Selective late steroid withdrawal after renal transplantation

Steroid withdrawal (SW) after paediatric renal transplantation (RTPL) is controversial. Selective late SW has been performed in our unit since 1995. The safety and effects of SW were analysed retrospectively in 47 patients undergoing RTPL between 1995 and 2004. Initial immunosuppression consisted of cyclosporine A, azathioprine or mycophenolate mofetil and steroids. Criteria for SW were: (1) stable renal function, (2) time interval after RTPL > or = 1 year, (3) no rejection or time interval after last rejection > or = 1 year and (4) good compliance. SW was performed in 30 patients at an age of 13.5 years (range 4.5-18.5) and 2.2 years (range 1-6.6) after RTPL. After SW, one patient experienced a steroid-sensitive rejection. Follow-up after SW (1.3 year; range 0.25-7.5) showed maintained renal function: glomerular filtration rate at SW and currently was 82 (65-128) and 82 (42-115) ml/min per 1.73 m(2), respectively. The number of patients on antihypertensive treatment did not significantly change (at SW: n = 15; currently: n = 11). Height and body mass index (BMI) remained stable: Median standard deviation score (SDS) for height/BMI at SW and currently was -1.1/0.2 and -0.8/0.1, respectively. Selective late SW was safe regarding renal function and had no significant effect on blood pressure and growth.

Assessment of risk factors for cardiovasuclar disease in pediatric renal transplant patients

Pediatric renal TP recipients are at risk for CVD. We performed a cross-sectional study of the prevalence of RF for CVD in 45 long-term pediatric renal TP patients. The time since TP was 42 months. The GFR was 87.8 +/- 3.4 mL/min/1.73 m(2); 25/45 (56%) had Stage 2-4 CKD. A total of 33% had elevated SBP and 24% had high DBP; 57% had elevated SBP or DBP. A total of 20% had elevated serum CHOL levels, while 45% had high serum TG levels. A total of 42% had high HCY levels and 50% had low HCT levels. The vast majority (66.7%) had at least two RF for CVD. A total of 18.2% had abnormal post-TP echocardiography results. There was a negative correlation between GFR and SBP, DBP, serum CHOL, HCY, and BMI. There was a positive correlation between GFR and HCT. Serum CHOL was significantly lower and SBP and DBP trended lower in patients on a SF immunosuppression regimen. Similarly, SBP and DBP trended higher and CHOL was significantly higher in patients receiving SRL vs. mycophenolate mofetil. We conclude that the majority of pediatric renal TP patients exhibit multiple CVD RF.

Avoiding steroids in pediatric renal transplantation: long-term experience from a single centre

We report our experience in pediatric renal transplantation avoiding steroids whenever possible. Immunosuppression consisted of an initial induction with antithymocyte globulin followed by maintenance therapy with a calcineurin inhibitor and MMF. Steroids were only given to selected patients because of the primary disease, recurrence, rejection, or PTLD. Thirty-four transplants grafted into 32 recipients between 1995 and 2005 were followed for a median of 3.5 yr (range 1-9.8). All patients survived. Graft rejection occurred in 10 cases during the first year post-transplantation and graft survival at one, five, and seven yr was 97, 88 and 88%, respectively. Steroids were given to half of the patients (n = 16); in nine cases due to rejection. Only four patients (13%) were continuously on steroids. Calculated GFR at one to five yr post-transplant were 73, 74, 68, 64, and 70 mL/min/1.73 m(2). Unfortunately PTLD occurred in three patients, but all survived with functioning grafts. Accordingly, our findings indicate that steroid avoidance in pediatric renal transplantation is possible with good results with respect to acute graft rejection as well as long-term graft survival.

Rapid steroid discontinuation for pediatric renal transplantation: a single center experience

To determine the outcomes of pediatric renal transplant recipients who received immunosuppression consisting of early withdrawal of corticosteroids at a single Northern California center. Protocols using minimal steroid exposure have been recently reported in adult transplant recipients with successful results. We examined the outcomes of pediatric renal transplant recipients who were managed at our center using a protocol with very early discontinuation of steroids after renal transplantation. We retrospectively studied the medical records of all renal transplant recipients followed at the Children's Hospital at the University of California, Davis Medical Center from 01/2004 to 12/2005. All patients were less than 18 yr of age at the time of transplantation. The immunosuppressive protocol included three tapering daily doses of methylprednisolone, together with five doses of thymoglobulin followed by maintenance therapy with tacrolimus and MMF. Eight patients with equal numbers of males and females were transplanted during this time period. There were equal numbers of Caucasians, African-Americans, Hispanics, and Asians. A total of 37.5% (3/8) of the subjects received preemptive transplantation, 25% (2/8) received peritoneal, and 37.5% (3/8) received hemodialysis before transplantation. The median (range) age at transplantation was 12.3 (3.1-16.0) year with a follow-up of 1.7 (0.9-2.8) year. At one yr post-transplantation, 57% (4/7) of patients still required anti-hypertensives. Three children required erythropoietin supplementation after transplantation. The mean delta height standard deviation score at 12 months was 0.20 +/- 0.56. There were no episodes of clinical acute rejection. One patient switched from tacrolimus to sirolimus due to biopsy-proven CAN. No patient became diabetic or required hypoglycemic agents. Surveillance biopsies showed no subclinical acute rejection in any patient. Steroid-free immunosuppression is safe in children after renal transplantation. Larger number of patients and longer follow-up are required to further confirm the effectiveness and safety of immunosuppression with rapid steroid discontinuation.

Effects of deflazacort vs. methylprednisone: a randomized study in kidney transplant patients

Metabolic effects of deflazacort vs. methylprednisone were studied in prepubertal patients after kidney transplantation. Thirty-one patients participated: 15 received deflazacort and 16 remained on methylprednisone. The study started at a mean of 2.1 years after transplantation, when patients were randomized to either continue with methylprednisone or switch to deflazacort. Height velocity increased more in the deflazacort than in the methylprednisone group only during the first 2 years: 5.4 +/- 0.5 vs. 3.5 +/- 0.3 cm/year, and 4.2 +/- 0.8 vs. 2.2 +/- 0.4 cm/year p=0.007, [by two-way analysis of variance (ANOVA)]. After 2 and 3 years, the number of patients who were overweight increased in the methylprednisone group and decreased in the deflazacort group; p<0.01. Lean body mass increased more in the deflazacort than in the methylprednisone group (p=0.003). Fat body mass increased only in the methylprednisone group (p<0.01). Total cholesterol and low-density-lipoprotein (LDL) cholesterol increased in the methylprednisone group (p<0.05 and p<0.01, respectively). Total and LDL cholesterol were reduced (p<0.01 and p<0.001, respectively), whereas high-density-lipoprotein (HDL) cholesterol increased (p<0.001) during deflazacort therapy. Lumbar spine bone mineral density (BMD) decreased in both groups, but total skeleton BMD decreased only in the methylprednisone group (p<0.001). Finally, normal glucose/insulin ratio, defined as > 7, was associated (p<0.05) with the deflazacort group. Our data suggest that deflazacort therapy might improve linear growth and lean body mass and prevent excessive bone loss and fat accumulation. It also leads to an improvement in lipoprotein profile without reduction in insulin sensitivity.

[Kidney transplantation in childhood and adolescence. Management of functional disorders and follow-up care of the kidney transplant recipient]

The causes that lead to terminal renal failure in children and adolescents and subsequently require dialysis are different from those in adults. Moreover, children with a functioning kidney transplant evidence an approximately fourfold higher survival probability than children on dialysis. This contribution describes kidney transplantation in light of the specific features for this age group.

Immunosuppression in pediatric solid organ transplantation: opportunities, risks, and management

The pediatric transplant community stands at a time of unprecedented choice of immunosuppressive agents - and with a legacy of morbidity from those agents used in the previous two decades. This review considers the clinical utility and side-effect profiles of immunosuppressants used widely in current practice (e.g., glucocorticoids, azathioprine, ciclosporin, tacrolimus, mycophenolate, and sirolimus) and those agents which are in increasing use or in evaluation (e.g., IL-2 receptor antibodies, everolimus, FTY720, LEA29Y, and deoxyspergualin). Further consideration is given to the wider drug interactions likely during the use of new immunosuppressant regimens and to our growing awareness of the influences of genetic heterogeneity on drug efficacy and handling. Finally, we consider the new demands being placed on the use of drug monitoring to regulate dosage of this new repertoire of immunosuppressants.

Mycophenolate mofetil in organ transplantation: focus on metabolism, safety and tolerability

Mycophenolate mofetil (MMF) received its first approval for the prevention of renal allograft rejection in 1995 and has now become the most frequently used antiproliferative agent in maintenance immunosuppressive therapy for kidney, pancreas, liver and heart transplantation. In addition, its use for the treatment of autoimmune diseases steadily increases. This review focuses on the miscellaneous pharmacodynamic properties of the drug, its pharmacokinetics in healthy subjects, recipients of different organ transplants and combination therapy with other pharmaceuticals, as well as its safety profile. The immunosuppressive activity of MMF is thought to derive mainly from the potent and selective inhibition of purine synthesis in both T and B lymphocytes. In contrast to other immunosuppressants on the market, it is metabolised primarily by glucuronidation and lacks nephrotoxicity, cardiovascular toxicity or diabetogenic potential, thus making it a suitable candidate for combination regimens. The most important side effects under MMF include gastrointestinal disorders, of which the underlying mechanisms are not yet fully understood, but seem to be complex and related to both effects of mycophenolic acid and its acyl glucuronide, as well as to decreased -immunity due to general immunosuppression after transplantation.

Longitudinal growth in children following kidney transplantation: from conservative to pharmacological strategies

Impairment of longitudinal growth in children with chronic renal failure (CRF) is multifactorial. It is mainly due to disturbances in the growth hormone (GH)/insulin-like growth factor (IGF)/IGF-binding protein axis. Growth failure can be managed by optimizing nutrition and fluid/electrolyte homeostasis, and overcoming the growth-inhibiting effects of uremia by high-dose recombinant human (rh) GH treatment. A sufficient catch-up growth is one of the determining issues for the overall success of pediatric kidney transplantation (Tx). However, despite satisfactory renal function, spontaneous catch-up growth is often insufficient as glucocorticoid treatment is the main inhibiting factor for longitudinal growth after Tx. In addition, longitudinal growth may be jeopardized by low glomerular filtration rate (GFR) and African American or Hispanic background. Supraphysiological doses of GH and/or IGF-I in vitro and in vivo can partially overcome the growth-inhibiting effects of glucocorticoid treatment. GH-associated increase of leukocyte proliferation and cytotoxicity with stimulated interferon synthesis have been demonstrated. However, it is not clear whether such stimulatory effects on leukocyte function are a transitory or a constant risk factor after organ Tx. Clinical trials of GH in children after renal Tx have suggested a rather moderate or transient effect of rhGH on the immune system, and corticosteroids induce a hyporesponsiveness to the action of GH. As long as corticosteroids are believed to be essential after renal Tx, rhGH should be considered to optimize longitudinal growth in children.

Methylprednisolone exposure in pediatric renal transplant patients

Glucocorticoid (GC) dosing is commonly based on body mass or surface area in children, although the drug effects appear to correlate with steroid exposure, rather than dose. We compared the area under the serum concentration-time curve (AUC) of methylprednisolone (MP) with a recombinant cell bioassay measuring serum glucocorticoid bioactivity (GBA), in prediction of side effects in 16 pediatric patients (5.4-18.4 years of age) 2.0-14.9 years after renal transplantation (TX). They received 0.3 mg/kg of MP orally and timed blood samples were drawn up to 8 h postdose. Serum MP concentrations correlated moderately with GBA (r= 0.65, p < 0.0001) with best linear fit at 6 and 8 h (r= 0.72, 0.79, respectively, p < 0.001). MP-AUC(t = 0-8) and GBA(t = 6) were significantly greater in patients who gained excessive weight soon after TX. Change in growth after TX was inversely correlated with MP-AUC (r= 0.73, p < 0.05) and GBA(t = 6) (r= 0.62, p < 0.05). No correlation of MP-AUC or GBA was found with blood glucose or serum lipid concentrations, glomerular filtration rate, bone mineral density or graft histology. In conclusion, GC exposure varies individually and dosing should be adjusted accordingly to control the adverse effects. GBA might provide a complementary tool for monitoring GC exposure but further studies are needed.

Control of hypertension in children after renal transplantation

The aim of this cross-sectional single-center study was to investigate the efficacy of hypertension control in children who underwent transplantation using ambulatory blood pressure (BP) monitoring, and to determine the risk factors associated with poor control of hypertension. Thirty-six children fulfilled the inclusion criteria. The mean age was 13.9+/-4.4 yr; the mean time after renal transplantation was 2.7+/-2.4 yr (0.5-10.1). Hypertension was defined as a mean ambulatory BP > or =95th centile for healthy children and/or requiring antihypertensive drugs. Hypertension was regarded as controlled if the mean ambulatory BP was <95th centile in children already on antihypertensive drugs, or uncontrolled if the mean ambulatory BP was > or =95th centile in treated children. Hypertension was present in 89% of children. Seventeen children (47%) had controlled hypertension, and 14 (39%) had uncontrolled hypertension. One child (3%) had untreated hypertension, and only four children (11%) showed normal BP without antihypertensive drugs. The efficacy of hypertensive control was 55% (17 of 31 children on antihypertensive drugs had a BP<95th centile), i.e. 45% of treated children still had hypertension. Children with uncontrolled hypertension had significantly higher cyclosporine doses (6.1 vs. 4.3 mg/kg/day, p=0.01) and tacrolimus levels (9.2 vs. 6.1 microg/L, p<0.05), and there was a tendency toward use of lower number of antihypertensive drugs (2.0 vs. 1.5 drugs/patient, p=0.06) and lower use of angiotensin-converting enzyme (ACE) inhibitors (7 vs. 35%, p=0.09) and diuretics (29 vs. 59%, p=0.14) than in children with controlled hypertension. In conclusion, nearly 90% of our children after renal transplantation are hypertensive and the control of hypertension is unsatisfactorily low. The control of hypertension could be improved by increasing the number of prescribed antihypertensive drugs, especially ACE inhibitors, and diuretics, or by using higher doses of currently used antihypertensives.

Prednisone withdrawal in pediatric kidney transplant recipients on tacrolimus-based immunosuppression: four-year data

Corticosteroids have been used in renal transplant immunosuppression for over 40 yr. Despite their adverse effects, steroid therapy continues to be part of early as well as maintenance immunosuppression in most pediatric renal transplant centers. The association of steroids with growth retardation, weight gain, and acne may be particularly distressing during the critical years of adolescence and young adulthood, increasing the risk of medication non-adherence. This study reviews the outcomes of pediatric renal transplant patients treated with low-dose tacrolimus, mycophenolate mofetil, or azathioprine, and planned prednisone withdrawal. Thirty-seven pediatric renal transplant recipients were withdrawn from steroids. The mean follow-up after steroid withdrawal was 42+/-19 months. Graft and patient survival were 100%. The mean serum creatinine levels and calculated creatinine clearances remained stable throughout the period of observation. The mean creatinine clearance was 96+/-24 mL/min/1.73 m2 at steroid withdrawal and 93+/-20 mL/min/1.73 m2 at the latest follow-up. Five patients restarted prednisone; in four (11%) it was for suspected or confirmed acute rejection. Improvements were observed in serum lipid profiles, blood pressure, and body mass index. Most patients experienced catchup or stable growth after prednisone withdrawal. Four patients developed viral infections; all were successfully treated. The potential benefits of steroid withdrawal in pediatric renal transplantation are supported by our results.

Special issues in pediatric kidney transplantation

Pediatric and adult kidney transplantation differ in many ways, but one of the most significant differences is the impact of kidney disease and kidney transplantation on growth and development in pediatric patients. Multiple facets of transplantation may have an impact on growth and development, including the timing of transplantation, choice of immunosuppressive agents, and the presence of hypertension. In addition, graft function has a significant impact on linear growth, and so preservation of function becomes important not only for general health and quality of life but also for optimizing growth. Other concerns in pediatric kidney transplantation include a heightened risk for posttransplantation infectious complications, including lymphoproliferative disease. In addition, the impact of immunosuppressive drugs on adherence to therapy is important. Although adherence is a complex and multifactorial process, immunosuppressive drugs that cause physical side effects may contribute to drug nonadherence because children, and particularly adolescents, may be inclined to stop taking medications associated with physical changes that differentiate them from their peers. Studies that further delineate factors that affect growth and development, risk for infectious complications, and nonadherence will be important to maximize outcomes in pediatric kidney transplantation.

Steroid elimination is coming of age

Steroid elimination is being achieved in organ transplantation. The newer generation of more powerful induction and maintenance immunosuppressants offer a new era of safe and effective steroid avoidance. The advantages of achieving independence from steroids definitely extend to the patient. Recent studies also suggest unexpected immunological benefits for the graft. Randomized studies of steroid avoidance and usage are warranted to confirm safety and efficacy, and to address pharmacokinetic and transcriptional changes as a result of steroid elimination, for optimum dosing and monitoring.

Toxicity-sparing protocols using mycophenolate mofetil in renal transplantation

The introduction of triple-therapy regimens that include a calcineurin inhibitor (CNI), steroids, and azathioprine greatly reduced the risk of acute rejection in renal transplantation. However, the long-term use of both CNIs and steroids is associated with serious toxicities that ultimately can impact patient/graft survival. Mycophenolate mofetil (MMF), a highly effective immunosuppressant with no known nephrotoxicity, has been shown to provide benefits in preserving long-term renal allograft function relative to azathioprine. For these reasons, MMF has become an integral component of toxicity-sparing maintenance regimens that seek to minimize patient exposure to CNIs and steroids. This paper provides an overview of current strategies for reducing the toxicities associated with these agents, which include both withdrawal and avoidance regimens with or without induction therapy. Data are accumulating that toxicity-sparing regimens involving MMF are safe and decrease the risk of side effects that accompany the use of CNIs and steroids. Future studies will determine how to best implement these regimens in the renal transplant population.

Drug dosage in children with reduced renal function

Drug dosing in paediatric nephrology requires multiple considerations and is therefore time-consuming and error-prone. This review combines dose adjustment guidelines for children with renal failure and information on the immature renal function of neonates and premature babies in order to help both paediatric nephrologists and neonatologists estimate drug doses for their patients.

Mycophenolate Mofetil in Pediatric Renal Transplantation

Mycophenolate mofetil (MMF) has become a popular immunosuppressive agent in pediatric renal transplantation and has helped to address the unique challenges of transplantation in this population. This paper reviews the early studies that proved MMF's efficacy in reducing the risk of acute renal rejection, as well as its safety and tolerability in comparison to azathioprine. Key conclusions about the pharmacokinetics of MMF from studies of MMF alone and in combination with other immunosuppressive therapies are outlined. The importance of therapeutic drug monitoring (TDM) in this population is also explored in this review. Finally, recent studies showing that newer agents used in combination with MMF can further increase efficacy and reduce the risk of adverse events such as posttransplant lymphoproliferative disease are discussed.

Development of growth and body mass index after pediatric renal transplantation

Suboptimal final height and marked weight gain after renal transplantation (RTx) are common and may result in obesity. Steroid free immunosuppression has been advocated to improve growth and limit weight gain. We evaluated retrospectively the evolution of growth and body mass index (BMI) after renal transplantation to study risk factors for weight gain under steroid based treatment. Sixty-four pediatric patients (age 9.9 +/- 5.0 yr) were included in the study. To allow comparison between different age groups, standard deviation scores (SDS) for height and BMI for height age were calculated at time of transplantation and 3, 6, 9, 12, 24, 36, 48 and 60 months later. Induction immunosuppression consisted of basiliximab, cyclosporine and prednisone. Growth retardation at time of RTx was obvious with a SDS for height of -2.20 +/- 1.34. Height during the first year improved to an SDS of -2.0 +/- 1.27 (p < 0.01) but did further not increase in year 2 and 3. More than 40% of all patients remained 2 SDS below normal mean. SDS BMI for height age at transplantation was -0.19 +/- 0.98 and increased significantly during the first 3 months after transplantation to +0.64 +/- 1.07 (p < 0.01). Thereafter, BMI remained stable but did not decline to pretransplant values. A SDS BMI for height age of more than 2 SDS was observed in 2, 6, 9 and 11% of children at RTx and 1, 2 and 3 yr later respectively. BMI gain over 3 yr was significantly enhanced in children whose parents (especially the mother) were overweight. No influence of gender, BMI at RTx, dialysis modality prior to RTx or rejection episodes could be detected. We conclude that after RTx children exhibit some improvement in growth but height remains suboptimal. The BMI does increase significantly during the first months after RTx and does not return to baseline values under steroid-based immunosuppression. Obesity (>2 SDS above normal) does not occur more often than in the normal population. The most predictive parameter of inappropriate weight gain during 3 yr is the BMI of the mother. We would speculate that steroids may play a major role in weight gain in the early phase after RTx. However, genetic or environmental factors predict the long-term weight development.

Steroid withdrawal in pediatric and adult renal transplant recipients

Corticosteroids are still a cornerstone in the immunosuppressive regimen in pediatric renal transplant recipients despite their numerous side effects, such as inhibition of longitudinal growth, body disfigurement, arterial hypertension, cardiovascular complications, osteopathy, and others. Previous attempts to spare steroids in cyclosporine (CsA)-based protocols have been associated with an increased risk for acute rejection episodes. The recent introduction of more-potent immunosuppressive medications, such as mycophenolate mofetil (MMF), have, however, renewed interest in steroid-sparing protocols to avoid or ameliorate steroid-associated side effects. Recent studies in Caucasian adult renal transplant recipients receiving CsA and MMF have shown a beneficial effect of late (>/=6 months post transplant) steroid withdrawal on steroid-associated side effects without the burden of an increased rate of acute rejection episodes. These favorable results compared with previous reports in patients on CsA and azathioprine (AZA) can be ascribed to the higher immunosuppressive potency of MMF compared with AZA. We have shown in a retrospective case control study in 40 pediatric renal transplant recipients that late steroid withdrawal is safe and successful in stable patients under an immunosuppressive maintenance therapy with CsA and MMF. The Mid-European Study Group on Pediatric Renal Transplantation and the Arbeitsgemeinschaft fur Padiatrische Nephrologie are currently performing a prospective randomized trial to validate these observations.