A prospective, randomized, multicenter trial of tacrolimus-based therapy with or without basiliximab in pediatric renal transplantation

Efficacy and safety of single-dose anti-thymocyte globulin versus basiliximab induction therapy in pediatric kidney transplant recipients: A retrospective comparative cohort study

BACKGROUND

This study aimed to compare the efficacy and safety of basiliximab (BAS) versus a single dose of anti-thymocyte globulin (r-ATG) induction therapy in pediatric kidney transplant recipients (KTRs).

METHODS

This single-center retrospective comparative cohort study included all pediatric KTRs from May 2013 to April 2018 and followed up to 12 months. In the first period, all recipients received BAS, while from May 2016, a single 3 mg/kg dose of r-ATG was instituted. Maintenance therapy consisted of a calcineurin inhibitor plus prednisone plus azathioprine or mycophenolate.

RESULTS

A total of 227 patients were included (BAS, n = 113; r-ATG, n = 114). The main combination of immunosuppressive drugs was tacrolimus, prednisone, and azathioprine in both groups (87% vs. 88%, p = .718). Patients receiving r-ATG showed superior survival-free of the composite endpoint (acute rejection, graft loss, or death; 76% vs. 61%, p = .003; HR 2.08, 1.29-3.34, p = .003) and lower incidence of biopsy-proven acute rejection (10% vs. 21%, p = .015). There was no difference in the overall incidence of CMV infection (33% vs. 37%, p = .457), PTLD (1% vs. 3%, p = .309), 30-day hospital readmissions (24% vs. 23%, p = .847), and kidney function at 12 months (86 ± 29 vs. 84 ± 30 mL/min/1.73m2, p = .614).

CONCLUSIONS

These data suggest that induction therapy with a single 3 mg/kg dose of r-ATG is associated with higher efficacy for preventing acute rejection and similar safety profile compared to BAS.

Emulation of the control cohort of a randomized controlled trial in pediatric kidney transplantation with Real-World Data from the CERTAIN Registry

BACKGROUND

Randomized controlled trials in pediatric kidney transplantation are hampered by low incidence and prevalence of kidney failure in children. Real-World Data from patient registries could facilitate the conduct of clinical trials by substituting a control cohort. However, the emulation of a control cohort by registry data in pediatric kidney transplantation has not been investigated so far.

METHODS

In this multicenter comparative analysis, we emulated the control cohort (n = 54) of an RCT in pediatric kidney transplant patients (CRADLE trial; ClinicalTrials.gov NCT01544491) with data derived from the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) registry, using the same inclusion and exclusion criteria (CERTAIN cohort, n = 554).

RESULTS

Most baseline patient and transplant characteristics were well comparable between both cohorts. At year 1 posttransplant, a composite efficacy failure end point comprising biopsy-proven acute rejection, graft loss or death (5.8% ± 3.3% vs. 7.5% ± 1.1%, P = 0.33), and kidney function (72.5 ± 24.9 vs. 77.3 ± 24.2 mL/min/1.73 m² P = 0.19) did not differ significantly between CRADLE and CERTAIN. Furthermore, the incidence and severity of BPAR (5.6% vs. 7.8%), the degree of proteinuria (20.2 ± 13.9 vs. 30.6 ± 58.4 g/mol, P = 0.15), and the key safety parameters such as occurrence of urinary tract infections (24.1% vs. 15.5%, P = 0.10) were well comparable.

CONCLUSIONS

In conclusion, usage of Real-World Data from patient registries such as CERTAIN to emulate the control cohort of an RCT is feasible and could facilitate the conduct of clinical trials in pediatric kidney transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Induction and maintenance immunosuppression in pediatric kidney transplantation-Advances and controversies

Advances in immunosuppression have improved graft survival in pediatric kidney transplant recipients; however, treatment-related toxicities need to be balanced against the possibility of graft rejection. Several immunosuppressive agents are available for use in transplant recipients; however, the optimal combinations of agents remain unclear, resulting in variations in institutional protocols. Lymphocyte-depleting antibodies, specifically ATG, are the most common induction agent used for pediatric kidney transplantation in the US. Basiliximab may be used for induction in immunologically low-risk children; however, pediatric data are scarce. CNIs and antiproliferative agents (mostly Tac and mycophenolate in recent years) constitute the backbone of maintenance immunosuppression. Steroid-avoidance maintenance regimens remain controversial. Belatacept and mTOR inhibitors are used in children under specific circumstances such as non-adherence or CNI toxicity. This article reviews the indications, mechanism of action, efficacy, dosing, and side effect profiles of various immunosuppressive agents available for pediatric kidney transplantation.

Primary pediatric live-donor-kidney transplant-recipients' outcomes by immunosuppression induction received in the United States

OBJECTIVE

We examined the association between induction type and outcomes of live-donor pediatric kidney recipients on tacrolimus and mycophenolate maintenance.

MATERIAL AND METHODS

We analyzed the SRTR standard analysis file to evaluate primary live-donor pediatric kidney recipients between 2000 and 2018. Recipients were grouped by induction type into three groups: alemtuzumab n = 289, anti-thymocyte n = 1197, and IL-2RA n = 1625. Kaplan-Meier curves were generated for recipient and death-censored graft survival. Predictors of recipient and allograft survival were examined using Cox proportional hazards models. Models were adjusted for age, sex, ethnicity, renal failure etiology, HLA-mismatches, transplant year, steroid maintenance, preemptive transplantation, payor type, and donor factors such as age, sex, and donor-recipient relationship. The transplant center was included as a random effect to account for inter-center variability.

RESULTS

Rejection rates at 6 months (Alemtuzumab 9.5% vs. r-ATG 5.7% vs. IL2-RA 5.3%; P: .023) and 12 months (Alemtuzumab 14.5% vs. r-ATG 10.8% vs. IL2-RA 9%; P: .028) were significantly higher in the alemtuzumab group. PTLD rate (Alemtuzumab 0.8% vs. r-ATG 2.2% vs. IL2-RA 1%; P: .028) was significantly higher in the anti-thymocyte group. In the multivariable models, induction type did not influence patient or death-censored graft survival within ten years post-transplant.

CONCLUSION

In this large cohort of standard immunological risk primary pediatric live-donor kidney recipients, as compared to IL-2RA, neither alemtuzumab nor anti-thymocyte globulin was associated with improved long-term graft or recipient survival. In the first year post-transplant, recipients of alemtuzumab induction had a higher rejection rate, while PTLD was more frequently observed in the anti-thymocyte recipients.

Primary pediatric deceased-donor kidney transplant recipients outcomes by immunosuppression induction received in the United States

BACKGROUND

We studied the association of induction immunosuppression and pediatric deceased-donor kidney recipient and graft survival.

METHODS

We utilized the SRTR to evaluate all primary pediatric deceased-donor kidney transplants from January 1st, 2000, through December 2018. We included only recipients who were maintained on tacrolimus and mycophenolate. Recipients were grouped by induction type: alemtuzumab n = 320, r-ATG n = 2091 and IL-2RA n = 2165. Recipient and allograft survival, and their predictors, were examined. Models were adjusted for age, sex, ethnicity, HLA-antigen mismatches, transplant year, steroid maintenance, pre-emptive transplantation and payor type, with the transplant center included as a random effect.

RESULTS

Rejection rates at 6 months (alemtuzumab 8.6% vs r-ATG 7.8% vs IL2-RA 9.2%; P = .30) and 12 months (alemtuzumab 17.2% vs r-ATG 15.7% vs IL2-RA 16.5%; P = .70) were not significantly different between induction groups. In the multivariable models, compared to IL-2RA neither alemtuzumab nor r-ATG was associated with improved recipient [alemtuzumab (HR 1.06, P = .88); r-ATG (HR 1.03, P = .84)] or graft survival [alemtuzumab (HR 1.18, P = .32); r-ATG (HR 1.10, P = .21)].

CONCLUSION

In this large cohort of standard immunological risk primary pediatric deceased-donor kidney recipients on tacrolimus and mycophenolate maintenance, depletional induction regimens were not associated with better rejection rates, recipient, or graft survival compared to IL-2RA induction. Racial, payor type, and sex-related outcome disparities were significant in this group independent of the induction choice.

Acute rejection in pediatric renal transplantation: Retrospective study of epidemiology, risk factors, and impact on renal function

AR is a major relevant and challenging topic in pediatric kidney transplantation. Our objective was to evaluate cumulative incidence of AR in pediatric kidney transplant patient, risk factors for this outcome, and impact on allograft function and survival. A retrospective cohort including pediatric patients that underwent kidney transplantation between 2011 and 2015 was designed. Risk factors for AR were tested by competing risk analysis. To estimate its impact, graft survival and difference in GFR were evaluated. Two hundred thirty patients were included. As a whole, the incidence of AR episodes was 0.16 (95% CI = 0.12-0.20) per person-year of follow-up. And cumulative incidence of AR was 23% in 1 year and 39% in 5 years. Risk factors for AR were number of MM (SHR 1.36 CI 1.14-1.63 P = .001); ISS with CSA, PRED, and AZA (SHR 2.22 CI 1.14-4.33 P = .018); DGF (SHR 2.49 CI 1.57-3.93 P < .001); CMV infection (SHR 5.52 CI 2.27-11.0 P < .001); and poor adherence (SHR 2.28 CI 1.70-4.66 P < .001). Death-censored graft survival in 1 and 5 years was 92.5% and 72.1%. Risk factors for graft loss were number of MM (HR 1.51 CI 1.07-2.13 P = .01), >12 years (HR 2.66 CI 1.07-6.59 P = .03), and PRA 1%-50% (HR 2.67 CI 1.24-5.73 P = .01). Although occurrence of AR did not influence 5-year graft survival, it negatively impacted GFR. AR was frequent in patients assessed and associated with number of MM, ISS regimen, DGF, CMV infection, and poor adherence, and had deleterious effect on GFR.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.

CD80 Insights as Therapeutic Target in the Current and Future Treatment Options of Frequent-Relapse Minimal Change Disease

Minimal change disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children, and it is well known for its multifactorial causes which are the manifestation of the disease. Proteinuria is an early consequence of podocyte injury and a typical sign of kidney disease. Steroid-sensitive patients react well with glucocorticoids, but there is a high chance of multiple relapses. CD80, also known as B7-1, is generally expressed on antigen-presenting cells (APCs) in steroid-sensitive MCD patients. Various glomerular disease models associated with proteinuria demonstrated that the detection of CD80 with the increase of urinary CD80 was strongly associated closely with frequent-relapse MCD patients. The role of CD80 in MCD became controversial because one contradicts finding. This review covers the treatment alternatives for MCD with the insight of CD80 as a potential therapeutic target. The promising effectiveness of CD20 (rituximab) antibody and CD80 inhibitor (abatacept) encourages further investigation of CD80 as a therapeutic target in frequent-relapse MCD patients. Therapeutic-based antibody towards CD80 (galiximab) had never been investigated in MCD or any kidney-related disease; hence, the role of CD80 is still undetermined. A new therapeutic approach towards MCD is essential to provide broader effective treatment options besides the general immunosuppressive agents with gruesome adverse effects.

Kidney transplant practice patterns and outcome benchmarks over 30 years: The 2018 report of the NAPRTCS

The NAPRTCS has collected clinical information on children undergoing renal transplantation since 1987 and now includes information on 12 920 renal transplants in 11 870 patients. Since the first data analysis in 1989, NAPRTCS reports have documented marked improvements in patient and allograft outcomes after pediatric renal transplantation in addition to identifying factors associated with both favorable and poor outcomes. The registry has served to document and influence practice patterns, clinical outcomes, and changing trends in renal transplantation and also provides historical perspective. This report highlights current practices in an era of major changes in DD kidney allocation and continuing steroid minimization. This report presents outcomes of the patients in the NAPRTCS transplant registry up to end of 2017. In particular, an increase in the cumulative incidence of late first AR has occurred in the most recent cohort, while all prior cohorts had a lower cumulative incidence of late first AR.

Defining a threshold for tacrolimus intra-patient variability associated with late acute cellular rejection in paediatric kidney transplant recipients

BACKGROUND

Late acute cellular rejection (LACR) is associated with poorer graft outcomes and non-adherence. Non-adherence to tacrolimus can be indirectly assessed by the intra-patient variability (IPV) of tacrolimus trough levels. The threshold of IPV associated with rejection is not known.

METHODS

We conducted a case-control study comparing 25 patients with biopsy-proven LACR against 25 stable controls matched for age group, primary diagnosis and time post-transplant. IPV was calculated using coefficient of variance (CV) and mean absolute deviation (MAD) using tacrolimus levels in the preceding 12 months. We also assessed the percentage time for tacrolimus levels < 4 μg/L (Tac < 4) and the concentration/weight-adjusted dose (C/D) ratio as a proxy marker of tacrolimus metaboliser status.

RESULTS

LACR patients had higher CV (median, IQR 44%, 36-61% v. 24%, 19-35%, p < 0.0001) and higher MAD (33%, 25-48% v. 19%, 15-26%, p < 0.0001). The MAD was less affected by outlying tacrolimus results. Receiver operating curve analysis of the MAD resulted in a sensitivity of 76% and specificity of 76% at a threshold of 26% (AUC 0.85, p < 0.05). LACR patients had more Tac < 4 (50% v. 26%, p < 0.05). There was no difference in C/D suggesting that good IPV can be maintained in fast metabolisers. Patients with LACR had significantly increased creatinine at 12-month follow-up despite treatment (108 v. 5 umol/L increase from baseline) and four patients lost their allograft.

CONCLUSIONS

Monitoring of tacrolimus IPV using the MAD may be a clinical marker for LACR. A threshold IPV of 26% can potentially be used as a therapeutic target pending further validation studies.

Long-term survival of full-thickness corneal xenografts from α1,3-galactosyltransferase gene-knockout miniature pigs in non-human primates

BACKGROUND

We aimed to investigate (a) the long-term survival of corneal grafts from α1,3-galactosyltransferase gene-knockout miniature (GTKOm) pigs in non-human primates as a primary outcome and (b) the effect of anti-CD20 antibody on the survival of corneal grafts from GTKOm pigs as a secondary outcome.

METHODS

Nine rhesus macaques undergoing full-thickness corneal xenotransplantation using GTKOm pigs were systemically administered steroid, basiliximab, intravenous immunoglobulin, and tacrolimus with (CD20 group) or without (control group) anti-CD20 antibody.

RESULTS

Graft survival was significantly longer (P = .008) in the CD20 group (>375, >187, >187, >83 days) than control group (165, 91, 72, 55, 37 days). When we compared the graft survival time between older (>7- month-old) and younger (≤7-month-old) aged donor recipients, there was no significant difference. Activated B cells were lower in the CD20 group than control group (P = .026). Aqueous humor complement C3a was increased in the control group at last examination (P = .043) and was higher than that in the CD20 group (P = .014). Anti-αGal IgG/M levels were unchanged in both groups. At last examination, anti-non-Gal IgG was increased in the control group alone (P = .013).

CONCLUSIONS

The GTKOm pig corneal graft achieved long-term survival when combined with anti-CD20 antibody treatment. Inhibition of activated B cells and complement is imperative even when using GTKO pig corneas.

Immunosuppressants in Organ Transplantation

The goal of immunosuppressive therapy post-transplantation in pediatric renal transplant recipients is to prevent acute and chronic rejection while minimizing drug side effects. Most therapies alter immune response mechanisms but are not immunologically specific, and a careful balance is required to find the dose that prevents rejection of the graft while minimizing the risks of overimmunosuppression leading to infection and cancer. While this chapter because of space constraints focuses on immunosuppressive therapy in pediatric renal transplant recipients, many aspects can be applied on pediatric recipients of other solid organ transplants such as the liver and heart. The major maintenance immunosuppressive agents currently used in various combination regimens are tacrolimus, cyclosporine, mycophenolate mofetil, azathioprine, everolimus, sirolimus, and glucocorticoids (steroids). Although data from adult renal transplantation trials are used to help guide management decisions in pediatric patients, immunosuppressive therapy in pediatric renal transplant recipients often must be modified because of the unique dosage requirements and clinical effects of these agents in children, including their impact on growth and development. The optimal immunosuppressive therapy post-transplant is not established. The goal remains to find the best combination of immunosuppressive agents that optimizes allograft survival by preventing acute rejection while limiting drug toxicities.

The potential impact of hematocrit correction on evaluation of tacrolimus target exposure in pediatric kidney transplant patients

BACKGROUND

Tacrolimus is an important immunosuppressive agent with high intra- and inter-individual pharmacokinetic variability and a narrow therapeutic index. As tacrolimus extensively accumulates in erythrocytes, hematocrit is a key factor in the interpretation of tacrolimus whole blood concentrations. However, as hematocrit values in pediatric kidney transplant patients are highly variable after kidney transplantation, translating whole blood concentration targets without taking hematocrit into consideration is theoretically incorrect. The aim of this study is to evaluate the potential impact of hematocrit correction on tacrolimus target exposure in pediatric kidney transplant patients.

METHODS

Data were obtained from 36 pediatric kidney transplant patients. Two hundred fifty-five tacrolimus whole blood samples were available, together responsible for 36 area under the concentration-time curves (AUCs) and trough concentrations. First, hematocrit corrected concentrations were derived using a formula describing the relationship between whole blood concentrations, hematocrit, and plasma concentrations. Subsequently, target exposure was evaluated using the converted plasma target concentrations. Ultimately, differences in interpretation of target exposure were identified and evaluated.

RESULTS

In total, 92% of our patients had lower hematocrit (median 0.29) than the reference value of adult kidney transplant patients. A different evaluation of target exposure for either trough level, AUC, or both was defined in 42% of our patients, when applying hematocrit corrected concentrations.

CONCLUSION

A critical role for hematocrit in therapeutic drug monitoring of tacrolimus in pediatric kidney transplant patients is suggested in this study. Therefore, we believe that hematocrit correction could be a step towards improvement of tacrolimus dose individualization.

Clinical aspects of tacrolimus use in paediatric renal transplant recipients

The calcineurin inhibitor tacrolimus, cornerstone of most immunosuppressive regimens, is a drug with a narrow therapeutic window: underexposure can lead to allograft rejection and overexposure can result in an increased incidence of infections, toxicity and malignancies. Tacrolimus is metabolised in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. This review focusses on the clinical aspects of tacrolimus pharmacodynamics, such as efficacy and toxicity. Factors affecting tacrolimus pharmacokinetics, including pharmacogenetics and the rationale for routine CYP3A5*1/*3 genotyping in prospective paediatric renal transplant recipients, are also reviewed. Therapeutic drug monitoring, including pre-dose concentrations and pharmacokinetic profiles with the available "reference values", are discussed. Factors contributing to high intra-patient variability in tacrolimus exposure and its impact on clinical outcome are also reviewed. Lastly, suggestions for future research and clinical perspectives are discussed.

Immunosuppressive therapy for kidney transplantation in children and adolescents: systematic review and economic evaluation

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation followed by induction and maintenance immunosuppressive therapy to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To systematically review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect,(®) Novartis Pharmaceuticals) and rabbit antihuman thymocyte immunoglobulin (Thymoglobuline,(®) Sanofi) as induction therapy and immediate-release tacrolimus [Adoport(®) (Sandoz); Capexion(®) (Mylan); Modigraf(®) (Astellas Pharma); Perixis(®) (Accord Healthcare); Prograf(®) (Astellas Pharma); Tacni(®) (Teva); Vivadex(®) (Dexcel Pharma)], prolonged-release tacrolimus (Advagraf,(®) Astellas Pharma); belatacept (BEL) (Nulojix,(®) Bristol-Myers Squibb), mycophenolate mofetil (MMF) [Arzip(®) (Zentiva), CellCept(®) (Roche Products), Myfenax(®) (Teva), generic MMF is manufactured by Accord Healthcare, Actavis, Arrow Pharmaceuticals, Dr Reddy's Laboratories, Mylan, Sandoz and Wockhardt], mycophenolate sodium, sirolimus (Rapamune,(®) Pfizer) and everolimus (Certican,(®) Novartis Pharmaceuticals) as maintenance therapy in children and adolescents undergoing renal transplantation.

DATA SOURCES

Clinical effectiveness searches were conducted to 7 January 2015 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science [via Institute for Scientific Information (ISI)], Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (HTA) (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted to 15 January 2015 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Databases (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and EconLit (via EBSCOhost).

REVIEW METHODS

Titles and abstracts were screened according to predefined inclusion criteria, as were full texts of identified studies. Included studies were extracted and quality appraised. Data were meta-analysed when appropriate. A new discrete time state transition economic model (semi-Markov) was developed; graft function, and incidences of acute rejection and new-onset diabetes mellitus were used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Three randomised controlled trials (RCTs) and four non-RCTs were included. The RCTs only evaluated BAS and tacrolimus (TAC). No statistically significant differences in key outcomes were found between BAS and placebo/no induction. Statistically significantly higher graft function (p < 0.01) and less biopsy-proven acute rejection (odds ratio 0.29, 95% confidence interval 0.15 to 0.57) was found between TAC and ciclosporin (CSA). Only one cost-effectiveness study was identified, which informed NICE guidance TA99. BAS [with TAC and azathioprine (AZA)] was predicted to be cost-effective at £20,000-30,000 per quality-adjusted life year (QALY) versus no induction (BAS was dominant). BAS (with CSA and MMF) was not predicted to be cost-effective at £20,000-30,000 per QALY versus no induction (BAS was dominated). TAC (with AZA) was predicted to be cost-effective at £20,000-30,000 per QALY versus CSA (TAC was dominant). A model based on adult evidence suggests that at a cost-effectiveness threshold of £20,000-30,000 per QALY, BAS and TAC are cost-effective in all considered combinations; MMF was also cost-effective with CSA but not TAC.

LIMITATIONS

The RCT evidence is very limited; analyses comparing all interventions need to rely on adult evidence.

CONCLUSIONS

TAC is likely to be cost-effective (vs. CSA, in combination with AZA) at £20,000-30,000 per QALY. Analysis based on one RCT found BAS to be dominant, but analysis based on another RCT found BAS to be dominated. BAS plus TAC and AZA was predicted to be cost-effective at £20,000-30,000 per QALY when all regimens were compared using extrapolated adult evidence. High-quality primary effectiveness research is needed. The UK Renal Registry could form the basis for a prospective primary study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013544.

FUNDING

The National Institute for Health Research HTA programme.

How randomised trials have improved the care of children with kidney disease

Randomised controlled trials (RCTs) provide the most reliable way to evaluate the benefits and harms of interventions. Participants are divided into groups using methods that balance the characteristics (both known and unknown) of the participants between treatment groups; thus, differences in outcomes are due to the interventions administered. From Cochrane Kidney and Transplant's Specialised Register, a comprehensive registry of trials in kidney disease, we identified 482 trials involving children. The vast majority concerned urinary tract infection (UTI; 134) and nephrotic syndrome (136). Most were small, with a median enrolment of 46 children, with only 26 trials enrolling 200 or more participants, and of these, 18 involved children with UTI. We discuss a number of important advances in the care of children with UTI with or without vesico-ureteric reflux, nephrotic syndrome, chronic kidney disease (CKD) and kidney transplantation that have been driven largely by trials in these conditions.

Biologics in renal transplantation

The biologics used in transplantation clinical practice include several monoclonal and polyclonal antibodies aimed at specific cellular receptors. The effect of their mechanisms of action includes depleting or blocking specific cell subpopulations, complement system, or removing circulating preformed antibodies and blocking their production. They are used in induction, desensitization ABO-incompatible renal transplantation, rescue therapy of steroid-resistant acute rejection, treatment of posttransplant recurrence of primary disease such as nephrotic syndrome or atypical hemolytic-uremic syndrome, and in late humoral rejection. There are various indications for the use of biologic agents before and early or late after renal transplantation in both high- and low-risk recipients. In the latter situation, the biologics-based induction is used to further minimize immunosuppression maintenance. The targets of several biologic agents are present across a variety of cells, and manipulation of the immune system with biologics may be associated with significant risk of acute and late-onset adverse events; therefore, clinical risk-versus-benefit ratio must be carefully balanced in every case. Several trials on novel biologics are reported in adults but not in the pediatric population.

Three-yr safety and efficacy of everolimus and low-dose cyclosporine in de novo pediatric kidney transplant patients

The three yr results of a multicenter trial in de novo pediatric KT treated with a proliferative signal inhibitor and low dose CNI are presented. Thirty-seven children (9.1 ± 5 yr old) received basiliximab, cyclosporine A (CyA C2:1400 ng/mL), (MMF C0:1.5-3 μg/mL), and prednisone. Three wk later everolimus was started (C0:5-10 ng/mL), CyA was reduced (C2:600 ng/mL after 90 days 300 ng/mL), and MMF discontinued. During the three-yr period patient and graft survivals were 96%. One patient died for causes unrelated to the immunosuppression. Cumulative acute rejection rate including protocol and indication biopsies was 21.9%. None of the patients had signs of chronic humoral rejection. Incidence of dnDSA was 5%, 11%, and 22% at one, two, and three yr post-transplant, respectively. Mean glomerular filtration rate measured at one yr and three yr post-transplant was 105.5 ± 31 and 110.7 ± 27 mL/min/1.73 m(2), respectively. A growth velocity of 7.7 ± 6.7 cm/yr was achieved with positive catch-up growth. No malignancy or post-transplant lymphoproliferative diseases were diagnosed. In conclusion, the treatment based on basiliximab induction, everolimus, low-dose cyclosporine, and low-dose prednisone leads to good long-term efficacy in de novo pediatric KT recipients.

Risk of serious opportunistic infections after solid organ transplantation: interleukin-2 receptor antagonists versus polyclonal antibodies. A meta-analysis

BACKGROUND

We aimed to evaluate and quantify the risk of serious opportunistic infections after induction with polyclonal antibodies versus IL-2 receptor antagonists (IL-2RAs) in randomized clinical trials.

METHODS

PRISMA guidelines were followed and random-effects models were performed.

RESULTS

70 randomized clinical trials (10,106 patients) were selected: 36 polyclonal antibodies (n = 3377), and 34 IL-2RAs (n = 6729). Compared to controls, polyclonal antibodies showed higher risk of serious opportunistic infections (OR: 1.93, 95% CI: 1.34-2.80; p < 0.0001); IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.80, 95% CI: 0.68-0.94; p = 0.009). Polyclonal antibodies were associated with higher risk of bacterial (OR: 1.58, 95% CI: 1.00-2.50; p = 0.049) and viral infections (OR: 2.37, 95% CI: 1.60-3.49; p < 0.0001), while IL-2RAs were associated with lower risk of cytomegalovirus (CMV) disease (OR: 0.73, 95% CI: 0.56-0.97; p = 0.032). Adjusted indirect comparison: compared to polyclonal antibodies, IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.41, 95% CI: 0.34-0.49; p < 0.0001), bacterial infections (OR: 0.51, 95% CI: 0.39-0.67; p < 0.0001) and CMV disease (OR: 0.58, 95% CI: 0.34-0.98; p = 0.043). Results remained consistent across allografts.

CONCLUSION

The risk of serious opportunistic infections, bacterial infections and CMV disease were all significantly decreased with IL-2RAs compared to polyclonal antibodies.

Pediatric kidney recipients may benefit from monitoring for donor-specific antibodies

There are limited data regarding the presence of DSAs and their effect on graft function in pediatric renal transplantation. The role for serial DSA monitoring in routine clinical practice is unclear. All patients attending a regional transplant clinic were tested for DSAs, measured using Luminex single/mixed antigen beads. Any patient having a positive result subsequently underwent historic testing on samples previously obtained. DSA-positive patients underwent prospective monitoring of DSAs, and correlation with clinical events was studied. Nine of a total of 50 patients (18%) were DSA-positive, of whom six had graft dysfunction. The DSA-positive cohort had significantly increased episodes of AR (p = 0.01). There were two graft losses in the DSA-positive group and none in the DSA-negative group. Eight of the DSA-positive group had potentially reduced exposure to IS because of either adherence issues or clinical indications. DSAs were associated with increased risk of rejection. There appears to be a role for serial monitoring of DSAs in patients where there has been a reduced exposure to IS so that early intervention with optimized IS can be considered.

Long-term outcomes of children after solid organ transplantation

Solid organ transplantation has transformed the lives of many children and adults by providing treatment for patients with organ failure who would have otherwise succumbed to their disease. The first successful transplant in 1954 was a kidney transplant between identical twins, which circumvented the problem of rejection from MHC incompatibility. Further progress in solid organ transplantation was enabled by the discovery of immunosuppressive agents such as corticosteroids and azathioprine in the 1950s and ciclosporin in 1970. Today, solid organ transplantation is a conventional treatment with improved patient and allograft survival rates. However, the challenge that lies ahead is to extend allograft survival time while simultaneously reducing the side effects of immunosuppression. This is particularly important for children who have irreversible organ failure and may require multiple transplants. Pediatric transplant teams also need to improve patient quality of life at a time of physical, emotional and psychosocial development. This review will elaborate on the long-term outcomes of children after kidney, liver, heart, lung and intestinal transplantation. As mortality rates after transplantation have declined, there has emerged an increased focus on reducing longer-term morbidity with improved outcomes in optimizing cardiovascular risk, renal impairment, growth and quality of life. Data were obtained from a review of the literature and particularly from national registries and databases such as the North American Pediatric Renal Trials and Collaborative Studies for the kidney, SPLIT for liver, International Society for Heart and Lung Transplantation and UNOS for intestinal transplantation.

Efficacy of basiliximab induction in poorly matched living donor renal transplantation

Non-depleting antibody induction has the best safety profile in transplant recipients without an increased risk of infection or malignancy. This observational study was performed in intermediate immunologic risk live donor renal transplants to assess basiliximab efficacy in patients on tacrolimus, mycophenolate, and prednisolone immunosuppression. A total of 46 patients on basiliximab induction were compared to risk matched 56 controls at the end of 6 and 12 months post-transplant. An additional cost of approximately Rs. 100,000/patient was incurred by the basiliximab group. The incidence of biopsy proven acute rejection in the control group (12.5%, 6 months and 20.5%, 1 year) and the basiliximab group (13%, 6 months and 18.9%, 1 year) was similar. At 6 months, there was a non-significant trend toward more steroid sensitive rejections and better glomerular filtration rate preservation in the basiliximab group (83.3%, 71.9 ml/min) versus the control group (28.6%, 62.2 ml/min). However, this difference was lost at 1 year (70.1 ml/min vs. 67.6 ml/min). The incidence of infections was similar and none of the patients had a malignancy. Death censored graft survival (94.6% basiliximab and 94.8% control) and the mean number of hospitalizations for all reasons at the end of 1 year were not different among the two groups. In our study, basiliximab induction did not confer an additional advantage in the intermediate risk live donor transplants in patients on tacrolimus and mycophenolate based triple drug immunosuppression.

Tacrolimus trough levels after month 3 as a predictor of acute rejection following kidney transplantation: a lesson learned from DeKAF Genomics

Most calcineurin inhibitor (CNI)-based protocols reduce blood trough goals approximately 2-3 months post-transplant in clinically stable kidney transplant recipients. The CNI target trough level to prevent rejection, after reduction, is unknown. Using a multivariate Cox proportional hazards model, we determined the association of time-varying tacrolimus (TAC) trough levels with acute rejection (AR) occurring in the first 6 months post-transplant, but specifically we assessed this association after 3 months. A total of 1930 patients received TAC-based immunosuppression prior to AR in a prospective study. Of the 151 (7.8%) who developed AR, 47 developed AR after 3 months post-transplant. In an adjusted time-varying multivariate model, each 1 ng/ml decrease in TAC trough levels was associated with a 7.2% increased risk of AR [hazards ratio (HR) = 1.07, 95% confidence interval (CI) (1.01, 1.14) P = 0.03] in the first 6 months. There was an additional 23% increased risk of AR with each 1 ng/ml decrease in the TAC trough levels in months 3-6 [HR = 1.23, 95% CI (1.06, 1.43) P = 0.008]. In conclusion, lower TAC trough levels were significantly associated with increased risk of AR in the first 6 months post-transplant with additional risk of AR between months 3 and 6 post-transplant. The timing and practice of TAC dose reduction should be personalized based on the individual's risk factors.

Monitoring of nonsteroidal immunosuppressive drugs in patients with lung disease and lung transplant recipients: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

Immunosuppressive pharmacologic agents prescribed to patients with diffuse interstitial and inflammatory lung disease and lung transplant recipients are associated with potential risks for adverse reactions. Strategies for minimizing such risks include administering these drugs according to established, safe protocols; monitoring to detect manifestations of toxicity; and patient education. Hence, an evidence-based guideline for physicians can improve safety and optimize the likelihood of a successful outcome. To maximize the likelihood that these agents will be used safely, the American College of Chest Physicians established a committee to examine the clinical evidence for the administration and monitoring of immunosuppressive drugs (with the exception of corticosteroids) to identify associated toxicities associated with each drug and appropriate protocols for monitoring these agents.

METHODS

Committee members developed and refined a series of questions about toxicities of immunosuppressives and current approaches to administration and monitoring. A systematic review was carried out by the American College of Chest Physicians. Committee members were supplied with this information and created this evidence-based guideline.

CONCLUSIONS

It is hoped that these guidelines will improve patient safety when immunosuppressive drugs are given to lung transplant recipients and to patients with diffuse interstitial lung disease.

Current status of immunosuppressive agents for solid organ transplantation in children

Immunosuppression after organ transplantation is complex and ever evolving. Over the past two decades, newer immunosuppressive agents have been introduced with an aim to provide better patient and graft survival. Improved therapeutic strategies have been developed offering the option to use combinations of drugs with non-overlapping toxicities. There are, however, only a few clinical studies with robust data to rationalize the use of these agents in children. This review will discuss the newer immunosuppressive agents used for solid organ transplant, their current status in post-transplant management and prevention of allograft rejection.

[Immunosuppressive treatment]

Immunosuppressive treatment following renal transplantation includes induction therapy during the initial period when the risk of rejection is higher. Depleting anti-lymphocyte antibodies are indicated mostly in patients who developped anti-HLA antibodies and following a second graft. Anti-IL2 receptor antibodies may be used in non-responders. After the first month, maintenance therapy mostly consists in the association of several immunosuppressants, mainly corticosteroids, an antimetabolic agent (azathioprine or mycophenolate mofetil) and a calcineurin inhibitor (cyclosporine or tacrolimus). Side effects associated with these treatments led to the development of new immunosuppressive protocols, with the reduction or withdrawal of corticosteroids treatment due to its deleterious effects on statural growth, and decreased doses of anti-calcineurin agents to reduce their nephrotoxic effect. These therapeutic options are possible in patients at low immunological risk.

The role of basiliximab in the evolving renal transplantation immunosuppression protocol

Basiliximab is a chimeric mouse-human monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor on activated T lymphocytes. It was shown in phase III trials to reduce the number and severity of acute rejection episodes in the first year following renal transplantation in adults and children, with a reasonable cost-benefit ratio. The drug does not increase the incidence of opportunistic infections or malignancies above baseline in patients treated with conventional calcineurin inhibitor-based immunosuppression. In the field of renal transplantation, basiliximab does not increase kidney or patient survival, despite the reduction in the number of rejection episodes. Basiliximab may reduce the incidence of delayed graft function. In comparison with lymphocyte-depleting antibodies basiliximab appears to have equal efficacy in standard immunological risk patients. Recently, IL-2 receptor monoclonal antibodies have been used with the objective of reducing or eliminating the more toxic elements of the standard immunosuppression protocol. Several trials have incorporated basiliximab in protocols designed to avoid or withdraw rapidly corticosteroids, as well as protocols which substitute target-of-rapamycin (TOR) inhibitors for calcineurin inhibitors.

Antithymocyte treatment of steroid-resistant acute rejection in renal transplantation

To evaluate the outcome of early (ER <3 months) and late (LR >3 months) episodes of corticosteroid resistant acute allograft rejection (CRR) treated with anti-thymocyte globulin (ATG) in pediatric renal allograft recipients. Retrospective study of 15 children, mean age 13.2 y, who received ATG for the treatment of biopsy proven CRR over a 15 year period. Seven children received ATG for ER (median 26 days post transplantation) and 8 for LR (median 763 days). There was a significant improvement in the 3 month eGFR (70.3 ml/min/1.73m(2), SD 22.3, p = 0.018) when compared with the value prior to ATG treatment (23.3 ml/min/1.73m(2), SD 10.2) in the ER group. In the LR group (4 DSA positive) there was no improvement in the eGFR at 3 months (42 ml/min/1.73m(2), SD 10.5, p = 0.32) when compared with the value prior to ATG (38 ml/min/1.73 m(2), SD 9.7). At final review, eGFR in the ER group was 72.3 ml/min/1.73m(2) (SD 33) vs. 37.7 ml/min/1.73m(2) (SD 17.9) in the LR group after a mean follow up of 10.4 y and 1.2 y, respectively. ATG therapy in CRR is associated with reversal of rejection and excellent graft outcome in children with ER. The benefits remain uncertain in LR, the etiology of which is multifactorial.

Minimizing steroid use in pediatric kidney recipients

Outcomes of pediatric kidney transplantation have improved significantly over the years, such that the majority of graft recipients survive to become adolescents and adults. In this article, the findings of some of the important trials that shaped the current therapeutic landscape of immunosuppression will be reviewed. As an evolving landscape, novel strategies are continuously being sought to address the significant challenges in pediatric transplantation. Among these challenges is the development of immunosuppressive strategies that not only minimize the risk of allograft rejection but also allow normal growth and developmental patterns in children. To that end, the growing clinical evidence that indicates that the use of steroid-sparing regimens is effective will be reviewed. Finally, a brief description of the TWIST study will be provided. This large-scale comparative study has been designed specifically to assess the effect of early steroid withdrawal on growth in pediatric renal transplant recipients. An overview of the preliminary analysis of the eagerly anticipated results of this landmark trial will also be provided.

Steroid minimization in pediatric renal transplantation: Early withdrawal or avoidance?

  Clinically important adverse events associated with the use of corticosteroids post-transplantation include hypertension, dyslipidemia, impaired glucose metabolism (including diabetes mellitus), growth retardation, bone fractures, and cosmetic problems. Over recent years, a number of studies have investigated the effect of minimizing exposure to corticosteroids in post-transplant immunosuppression protocols in both adults and children. In pediatric patients, several different approaches have been evaluated, including late steroid withdrawal, early steroid withdrawal, and complete steroid avoidance with or without poly- or monoclonal antibody induction and a variety of maintenance immunosuppressants. This manuscript reviews the key studies and documents the specific clinical benefits associated with steroid minimization. The development of PTLD and bone marrow suppression has been a major safety concern in some of these studies. These studies and other adverse effects are discussed.

Systematic review of randomized controlled trial quality in pediatric kidney transplantation

Limited pediatric-specific research can lead to sub-standard evidence for clinical decision making in children. We sought to systematically evaluate the methodological quality and the reporting standards of randomized controlled trials (RCTs) of transplantation trials in children. We included RCTs of kidney transplant recipients that had enrolled at least one child (aged 17 years or less) and that were reported in English language, peer reviewed journals from 2000 onward in the Cochrane Renal Group's specialized register. Trial reports were assessed against the 22 item checklist of the CONsolidated Standards Of Reporting Trials (CONSORT) statement. Twenty-seven RCTs were included. The reporting of the essential components of the methods, results and discussion domains was unsatisfactory. Mean CONSORT criteria score for the pediatric trials was 67% and 66% for trials including both adults and children (p value for the difference = 1.00). Trial reporting quality in pediatric transplantation trials is not different from trials involving adults. It is evident that the reporting standards of RCTs in both adult and pediatric transplantation require major improvements. This work bench-marks current standards for future quality improvement.

Induction therapy in pediatric kidney transplant recipients discharged with a triple drug immunosuppressive regimen

We evaluated the effectiveness of induction therapy on transplant outcomes during 2004-2007 in the United States. We retrospectively reviewed OPTN/UNOS registry and selected kidney pediatric (<21-yr) recipients that received no induction (NoIND), IL-2RA, or rabbit anti-THY and were discharged with a triple drug immunosuppressive maintenance regimen, including steroids. Of 2932 recipients, 20%, 36%, and 43% were in NoIND, THY, and IL-2RA groups, respectively. The majority received tacrolimus (88%) and MMF (89%) at discharge. There was no association of induction with the risk of acute rejection even after adjusting for known cofounders. Compared to NoIND, IL2-RA, but not THY, had a modest decrease (3%) in absolute rate of graft loss and was associated with a risk reduction ratio of 0.51 (95% CI, 0.31-0.84) in one-yr graft loss. At three yr, no induction agent was associated with decreased graft loss. In conclusion, induction agents were used in 80% of pediatric kidney recipients discharged with a triple drug immunosuppressive maintenance regimen between 2004-2007 in the United States. Neither THY nor IL-2RA was associated with reduced rejection episodes. The use of induction therapy was not associated with improvement in three-yr graft survival.

Induction therapy: why, when, and which agent?

The long-term outcome of paediatric transplantation has improved over the last decade with an increase in the armamentarium of immunosuppressive agents. However, the battle against the hostile immune response at the time of and after transplantation continues. Induction therapy can reduce early injury, to optimize the long-term allograft survival. The goal of induction immunosuppression in paediatric transplantation is to permit the use of lower doses of maintenance immunosuppressive agents without increased rates of acute allograft rejection and chronic allograft damage. The aim of this review is to summarize the current literature relating to the use of antibody agents for induction in paediatric solid organ transplantation.

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.

Interleukin 2 receptor antagonists for kidney transplant recipients

BACKGROUND

Interleukin 2 receptor antagonists (IL2Ra) are used as induction therapy for prophylaxis against acute rejection in kidney transplant recipients. Use of IL2Ra has increased steadily since their introduction, but the proportion of new transplant recipients receiving IL2Ra differs around the globe, with 27% of new kidney transplant recipients in the United States, and 70% in Australasia receiving IL2Ra in 2007.

OBJECTIVES

To systematically identify and summarise the effects of using an IL2Ra, as an addition to standard therapy, or as an alternative to another immunosuppressive induction strategy.

SEARCH STRATEGY

We searched the Cochrane Renal Group's specialised register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE to identify new records, and authors of included reports were contacted for clarification where necessary.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in all languages comparing IL2Ra to placebo, no treatment, other IL2Ra or other antibody therapy.

DATA COLLECTION AND ANALYSIS

Data was extracted and assessed independently by two authors, with differences resolved by discussion. Dichotomous outcomes are reported as relative risk (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 71 studies (306 reports, 10,537 participants). Where IL2Ra were compared with placebo (32 studies; 5,784 patients) graft loss including death with a functioning graft was reduced by 25% at six months (16 studies: RR 0.75, 95% CI 0.58 to 0.98) and one year (24 studies: RR 0.75, 95% CI 0.62 to 0.90), but not beyond this. At one year biopsy-proven acute rejection was reduced by 28% (14 studies: RR 0.72, 95% CI 0.64 to 0.81), and there was a 19% reduction in CMV disease (13 studies: RR 0.81, 95% CI 0.68 to 0.97). There was a 64% reduction in early malignancy within six months (8 studies: RR 0.36, 95% CI 0.15 to 0.86), and creatinine was lower (7 studies: MD -8.18 micromol/L 95% CI -14.28 to -2.09) but these differences were not sustained.When IL2Ra were compared to ATG (16 studies, 2211 participants), there was no difference in graft loss at any time point, or for acute rejection diagnosed clinically, but the was benefit of ATG therapy over IL2Ra for biopsy-proven acute rejection at one year (8 studies:, RR 1.30 95% CI 1.01 to 1.67), but at the cost of a 75% increase in malignancy (7 studies: RR 0.25 95% CI 0.07 to 0.87) and a 32% increase in CMV disease (13 studies: RR 0.68 95% CI 0.50 to 0.93). Serum creatinine was significantly lower for IL2Ra treated patients at six months (4 studies: MD -11.20 micromol/L 95% CI -19.94 to -2.09). ATG patients experienced significantly more fever, cytokine release syndrome and other adverse reactions to drug administration and more leucopenia but not thrombocytopenia. There were no significant differences in outcomes according to cyclosporine or tacrolimus use, azathioprine or mycophenolate, or to the study populations baseline risk for acute rejection. There was no evidence that effects were different according to whether equine or rabbit ATG was used.

AUTHORS' CONCLUSIONS

Given a 38% risk of rejection, per 100 recipients compared with no treatment, nine recipients would need treatment with IL2Ra to prevent one recipient having rejection, 42 to prevent one graft loss, and 38 to prevent one having CMV disease over the first year post-transplantation. Compared with ATG treatment, ATG may prevent some experiencing acute rejection, but 16 recipients would need IL2Ra to prevent one having CMV, but 58 would need IL2Ra to prevent one having malignancy. There are no apparent differences between basiliximab and daclizumab. IL2Ra are as effective as other antibody therapies and with significantly fewer side effects.

Use of basiliximab induction in low-immunological risk renal transplant recipients receiving tacrolimus-based immunosuppression

Basiliximab induction treatment has been shown to reduce the incidence of acute rejection episodes without the secondary side effects observed with antilymphocyte polyclonal antibodies. We analyzed our experience with basiliximab induction associated with tacrolimus-based immunosuppression among low-immunological risk renal transplant recipients. We retrospectively analyzed 55 renal transplantation patients of low inmunological risk who received organs from donors younger than 55 years. We compared a group of 21 patients (38.9%; group 1) treated with basiliximab (Simulect, Novartis, Basel, Switzerland) with 33 patients (61.1%; group 2) without induction. The patient groups did not differ in recipient age (46.39 +/- 11.1 in group 1 vs 41.82 +/- 11.02 years in group 2; P = .25), donor age (36.71 +/- 14.72 vs 35.09 +/- 14.63 years; P = .69), or recipient and donor gender. No differences were observed in dose or tacrolimus levels during follow-up. The incidences of delayed graft function (DGF; 28.6% vs 28.1%; P = .97) and of acute rejection episodes (9.5% vs 15.6%; P = .52) were similar in both groups. Serum creatinine and proteinuria levels (P > .05) and hospital admissions due to infections (36.4 vs 35.7%; P = .97) were also similar in both groups. At 1 year graft survival rates were 92% and 96% (P = .97) in groups 1 and 2, respectively. Considering our findings and the costs of basiliximab treatment, we conclude that routine administration of basiliximab cannot be justified in young, low-immunological risk transplant recipients undergoing tacrolimus-based immunosuppression.

Multicentre prospective randomised trial of tacrolimus, azathioprine and prednisolone with or without basiliximab: two-year follow-up data

A total of 192 children and adolescents undergoing renal transplantation were randomly chosen to receive tacrolimus, azathioprine and corticosteroids (TAS, n = 93) or tacrolimus, azathioprine, corticosteroids and two doses of basiliximab (TAS + B, n = 99). Six-month outcome data have previously been reported; this manuscript reports the 2-year data. Complete 2-year data were available on 164 (85.4%) of the original 192 patients. There was a single death in the TAS arm. Kaplan-Meier estimates of survival free of graft loss at 2 years were 94.9% in the TAS + B arm and 89.6% in the TAS arm [hazard ratio (HR) 0.52; 95% confidence interval (CI) 0.17 to 1.54, P = 0.23]. Estimates of survival free from rejection at 2 years were 75.2% in the TAS + B arm and 68.7% in the TAS arm (HR 0.81; 95% CI 0.46 to 1.40, P = 0.44). The mean estimated glomerular filtration rate (GFR) at 2 years, was 65.8 ml/min per 1.73 m(2) body surface area in the TAS arm and 66.7 ml/min per 1.73 m(2) in the TAS + B arm (P = 0.78). Blood pressure and cholesterol levels were similar in the two arms, and there was no evidence of a difference in the incidence of infection or malignancy. These data provide further evidence of a lack of benefit associated with the addition of basiliximab to a TAS regimen for European paediatric renal transplant recipients at low immunological risk.

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.

Calcineurin inhibitor sparing in paediatric solid organ transplantation : managing the efficacy/toxicity conundrum

Despite their efficacy, the calcineurin inhibitors (CNIs) ciclosporin and tacrolimus carry a risk of debilitating adverse effects, especially nephrotoxicity, that affect the long-term outcome and survival of children who are given organ transplants. Simple reduction in dosage of CNI has little or no long-term benefit on their adverse effects, and complete withdrawal without threatening graft outcome may only be possible after liver transplantation. Until the last decade, the only option was to increase corticosteroid and/or azathioprine doses, which imposed additional long-term hazards. Considered here are the emerging generation of new agents offering an opportunity for improving long-term graft survival, minimizing CNI-related adverse events and ensuring patient well-being.A holistic, multifaceted strategy may need to be considered - initial selection and optimized use and monitoring of immunosuppressant regimens, early recognition of indicators of patient and graft dysfunction, and, where applicable, early introduction of CNI-sparing regimens facilitating CNI withdrawal. The evidence reviewed here supports these approaches but remains far from definitive in paediatric solid organ transplantation. Because de novo immunosuppression uses CNI in more than 93% of patients, reduction of CNI-related adverse effects has focused on CNI sparing or withdrawal.A recurring theme where sirolimus and mycophenolate mofetil have been used for this purpose is the importance of their early introduction to limit CNI damage and provide long-term benefit: for example, long-term renal function critically reflects that at 1 year post-transplant. While mycophenolic acid shows advantages over sirolimus in preserving renal function because the latter is associated with proteinuria, sirolimus appears the more potent immunosuppressant but also impairs early wound healing. The use of CNI-free immunosuppressant regimens with depleting or non-depleting antibodies plus sirolimus and mycophenolic acid needs much wider investigation to achieve acceptable rejection rates and conserve renal function. The adverse effects of the alternative immunosuppressants, particularly the dyslipidaemia associated with sirolimus, needs to be minimized to avoid replacing one set of adverse effects (from CNIs) with another. While we can only conjecture that judicious combinations with the second generation of novel immunosuppressants currently in development will provide these solutions, a rationale of low-dose therapy with multiple immunosuppressants acting by complementary mechanisms seems to hold the promise for efficacy with minimal toxicity until the vision of tolerance achieves reality.

Safety and pharmacokinetics of daclizumab in pediatric renal transplant recipients

This study examined the safety and pharmacokinetics/pharmacodynamics of daclizumab in combination with mycophenolate mofetil (or azathioprine), corticosteroids, and cyclosporine or tacrolimus, in 61 pediatric renal allograft recipients in three age groups: less than or equal to five yr (n = 18), 6-12 yr (n = 18), and 13-17 yr (n = 25). The dosing regimen was daclizumab 1.0 mg/kg before transplantation, followed by four biweekly doses. The pharmacokinetics of daclizumab were described using NONMEM software. Median (range) estimated trough daclizumab levels achieved on day 56 (before dose 5) were 3.88 microg/mL (2.48-8.78), 4.54 microg/mL (1.79-18.7), and 4.94 microg/mL (0.05-10.6) in the less than or equal to five yr (n = 15), 6-12 yr (n = 17), and 13-17 yr (n = 22) age groups, respectively. Steady-state median (range) daclizumab exposures were 2040 mg x h/mL (1585-3778), 2757 mg x h/mL (1873-3494) and 3297 mg x h/mL (1705-6453), respectively. Saturation of the IL-2R occurred rapidly and was maintained for greater than or equal to three months after transplantation. Daclizumab was generally well-tolerated with no acute allergic or anaphylactic reactions, deaths or malignancies during the study. The proportion of patients who developed acute rejection at six and 12 months was 8.5% and 16.7%, respectively. This study shows that adding daclizumab at 1 mg/kg to standard immunosuppressive therapy provides safe and effective IL-2R blockade.

Standard dosing of tacrolimus leads to overexposure in pediatric renal transplantation recipients

Tacrolimus dosage in pediatric RTRs is empirically based on weight. There is evidence that adolescents are at greater risk of toxicity than young children on this dosing regimen. We investigated the rate of tacrolimus overexposure within the first three wk post-transplantation in pediatric RTRs receiving tacrolimus 0.15 mg/kg twice daily. Of 63 RTRs studied, 41 (65.1%) experienced a tacrolimus level above the therapeutic range (supratherapeutic), the majority (48.8%) on days two to four post-transplant. Patients with supratherapeutic levels were older (14.2 vs. 9.9 yr, p = 0.016), taller (146.7 vs. 126.5 cm, p = 0.029), larger (1.36 vs. 1.01 m(2), p = 0.039) and heavier (44.1 vs. 29.3 kg, p = 0.043) and by day 12 were receiving much lower tacrolimus doses than those without supratherapeutic levels (0.425 vs. 0.198 mg/kg/day, p = 0.0002). Supratherapeutic levels were more common among white (British) children than other ethnic groups (74 vs. 45%, p = 0.02). There were no observed differences in rates of patient or graft survival, or acute rejection during the three-yr study period. Adolescent patients appear to be at greater risk of excessive tacrolimus dosing on a standard regimen. We therefore outline a regimen restricting tacrolimus dosage given to larger/older patients, but emphasize the need for a prospective randomized trial to define optimal dosing.

Basiliximab induction therapy for live donor kidney transplantation: a long-term follow-up of prospective randomized controlled study

BACKGROUND/AIMS

The effect of basiliximab induction therapy on long-term patient and graft survival is not yet clear. We aimed to evaluate if there is any advantage of routine basiliximab induction on the long-term outcome of living related donor kidney transplantation.

METHODS

One hundred adult recipients with their first kidney allograft were randomized into two treatment groups, one group received basiliximab and the second served as a control. All patients received a maintenance triple immunosuppressive therapy (steroids, cyclosporine (CsA) micro-emulsion and azathioprine) and were followed up thoroughly for 7 years.

RESULTS

Basiliximab significantly reduced the proportion of patients who experienced acute rejection in the first year (18/50) when compared to the control group (31/50), and in 7 years (28/50) when compared to (37/50) in controls. The cumulative steroid dose used throughout the whole study period was significantly lower in the basiliximab group. The overall incidence of post-transplant complications was comparable among the two treatment groups. There was no significant difference in patient or graft survival; 7 years patient and graft survival were 92, 76% for basiliximab and 92, 80% for the control group, respectively.

CONCLUSION

Routine basiliximab induction significantly reduced the incidence of acute rejection without any noticeble beneficial effect on the long-term renal transplantation outcome.