A prospective, pilot study of early corticosteroid cessation in high-immunologic-risk patients: the Cincinnati experience

Does steroid-free immunosuppression improve the outcome in kidney transplant recipients compared to conventional protocols?

Steroids continue to be the cornerstone of immune suppression since the early days of organ transplantation. Steroids are key component of induction protocols, maintenance therapy and in the treatment of various forms of rejection. Prolonged steroid use resulted in significant side effects on almost all the body organs owing to the presence of steroid receptors in most of the mammalian cells. Kidney allograft recipients had to accept the short and long term complications of steroids because of lack of effective alternatives. This situation changed with the intro-duction of newer and more effective immune suppression agents with a relatively more acceptable side effect profile. As a result, the clinicians have been contemplating if it is the time to abandon the unquestionable reliance on maintenance steroids in modern transplantation practice. This review aims to evaluate the safety and efficacy of various steroid-minimization approaches (steroid avoidance, early steroid withdrawal, and late steroid withdrawal) in kidney transplant recipients. A meticulous electronic search was conducted through the available data resources like SCOPUS, MEDLINE, and Liverpool University library e-resources. Relevant articles obtained through our search were included. A total number of 90 articles were eligible to be included in this review [34 randomised controlled trials (RCT) and 56 articles of other research modalities]. All articles were evaluating the safety and efficacy of various steroid-free approaches in comparison to maintenance steroids. We will cover only the RCT articles in this review. If used in right clinical context, steroid-free protocols proved to be comparable to steroid-based maintenance therapy. The appropriate approach should be tailored individually according to each recipient immuno-logical challenges and clinical condition.

Systemic immunosuppression in limbal stem cell transplantation: best practices and future challenges

The objective of this study was to evaluate systemic immunosuppression regimens used for patients undergoing ocular surface stem cell transplantation, including their benefits and adverse effects in the adjunctive management of limbal stem cell deficiency (LSCD). A systematic literature review was conducted using the MEDLINE and EMBASE databases (1980-2015). Data were collected on surgical intervention(s), type of immunosuppressive agent(s), duration of immunosuppression, percentage with stable ocular surface at last follow-up, mean follow-up time, and demographics. Data were also collected on adverse ocular and systemic outcomes. Sixteen reports met the inclusion criteria. There were no randomized controlled studies. Three studies were noncomparative prospective case series, whereas the majority were retrospective case series. Bilateral severe LSCD was the most common disease (50%), and keratolimbal allograft was the most common intervention (80%). Immunosuppressive regimens showed a progression from early studies using oral cyclosporine to later studies using combinations of mycophenolate mofetil and tacrolimus. Most studies included a course of high-dose systemic corticosteroids. For patients adherent to long-term systemic immunosuppression, stable ocular surface rates of 70%-80% at last follow-up were reported. Adverse effects included hypertension, diabetes mellitus, and biochemical abnormalities managed with pharmacotherapy or discontinuation of offending agents. There were no cases of mortality related to immunosuppression. However, the current literature does not elucidate which immunosuppressive regimen is most efficacious for different categories of LSCD or graft types. Evidence-based guidelines for systemic immunosuppression in limbal allograft therapy would benefit from randomized controlled and/or additional prospective studies. Long-term immunosuppression would benefit from close collaboration between ophthalmologists and transplant specialists to individualize treatments.

Early corticosteroid withdrawal in recipients of renal allografts: a single-center report of ethnically diverse recipients and recipients of marginal deceased-donor kidneys

BACKGROUND

Candidacy for kidney transplantation is being progressively liberalized, and the safety and efficacy of early withdrawal of corticosteroids in high-risk patients have not been fully characterized.

METHODS

We analyzed the safety and efficacy of an early corticosteroid withdrawal regimen of rabbit antithymocyte globulin induction, tacrolimus, mycophenolate mofetil, and steroid withdrawal by day 5 after transplantation in our study cohort of 634 kidney transplant recipients that included 27% African American and 18% Hispanic recipients. Fifty-five percent of the recipients were recipients of deceased-donor kidneys, and 46% of deceased-donor kidneys were kidneys from expanded criteria donors.

RESULTS

Kaplan-Meier patient survival at 1, 3, and 5 years after transplantation was 98.6%, 94.6%, and 90.2%, and death-censored graft survival was 96.2%, 91.9%, and 87.6%, respectively. During a mean follow-up of 57 months, 89.3% of patients remained off of corticosteroids, and the incidence of acute rejection including subclinical rejection identified by protocol biopsy was 12.0%. Multivariable analysis identified age older than 60 years as protective against (P=0.01) and the African American ethnicity as a risk factor for (P=0.03) rejection. Delayed graft function (P<0.0001), rejection (P<0.0001), and transplant panel reactive antibody 20% or more (P=0.03) were risk factors for graft loss. Opportunistic infections included viral in 15.3%, fungal in 1.6%, and parasitic in 0.6% of the patients. Posttransplantation malignancy occurred in 9.1% of patients.

CONCLUSIONS

An early corticosteroid withdrawal regimen of rabbit antithymocyte globulin induction, tacrolimus, and mycophenolate mofetil is associated with excellent patient and kidney graft survival in an ethnically diverse population with risk factors for poor outcomes.

Ten-year outcome after rapid discontinuation of prednisone in adult primary kidney transplantation

BACKGROUND AND OBJECTIVES

Rapid discontinuation of prednisone after kidney transplantation potentially allows for minimization of steroid-related side effects. Although intermediate-term data with rapid discontinuation of prednisone have been promising, concern still exists regarding long-term outcomes. The 10-year experience is reported herein.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between October 1, 1999 and December 31, 2010, 1241 adult primary kidney transplants (791 living donor and 450 deceased donor) were performed using a protocol in which prednisone is discontinued after postoperative day 5. The 10-year actuarial recipient and graft survival rates and prednisone-related side effects were studied.

RESULTS

Ten-year actuarial patient survival was 71% for living donor transplants and 62% for deceased donor transplants; 10-year graft survival was 61% for living donor transplants and 51% for deceased donor transplants, and was comparable to 10-year Scientific Registry of Transplant Recipients national data. Ten-year death-censored graft survival was 79% for living donor transplants and 80% for deceased donor transplants. Ten-year acute rejection rates were 25% for deceased donor transplants and 31% for living donor transplants; 10-year chronic rejection (interstitial fibrosis/tubular atrophy) rates were 39% for deceased donor transplants and 47% for living donor transplants. For nondiabetic recipients of living donor or deceased donor allografts, the incidence of new-onset diabetes was significantly lower than in historical controls on prednisone (P<0.001). We also found significantly reduced rates of cataracts, avascular necrosis, and cytomegalovirus infection in some subgroups.

CONCLUSIONS

Prednisone-related side effects can be minimized in a protocol incorporating rapid discontinuation of prednisone for maintenance immunosuppression. Ten-year patient and graft outcomes remain acceptable.

Early steroid withdrawal in repeat kidney transplantation

BACKGROUND AND OBJECTIVES

Kidney re-transplantation (KRT) candidates are considered at high risk for graft failure. Most of these patients are kept on a chronic steroid maintenance (CSM) regimen. The safety of early steroid withdrawal (ESW) remains unanswered in KRT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study was aimed at comparing the outcomes of ESW and CSM in KRT. Retrospective analysis of 113 KRT patients (ESW, n=59; CSM, n=54) was performed. All patients received rabbit anti-thymocyte globulin/steroid induction and were maintained on mycophenolate/tacrolimus (±steroids).

RESULTS

One- and 5-year patient survival for the ESW and the CSM group were not significantly different (98 versus 96% and 91 versus 88%, respectively; P=0.991). No significant difference was seen in the graft survival for both groups at 1 and 5 years (98 versus 93% and 80 versus 74%, respectively; P=0.779). Mean 1- and 5-year estimated GFR was not statistically different between the groups (P=0.773 and 0.790, respectively). The incidence of acute rejection at 1 year was 17 and 22% in ESW and CSM patients, respectively (P=0.635). Compared with the ESW group, patients in the CSM group were more likely to be hyperlipidemic (P=0.044), osteoporotic (P=0.010), post-transplant diabetics (P=0.051) and required more medications to control BP (P=0.004).

CONCLUSIONS

ESW seems to be a reasonable approach in KRT recipients because the short and intermediate patient survival, graft survival, and graft function is comparable to CSM immunosuppression.

Interleukin-2 receptor blockade with humanized monoclonal antibody for solid organ transplantation

IMPORTANCE OF THE FIELD

Induction therapy has reduced the incidence of acute rejection compared with historical standards. The potency of currently available induction immunosuppression is not without risk and should be carefully considered. Induction with daclizumab, an IL-2 receptor antagonist, has been used safely and effectively for over 10 years across different transplant types. As a result of daclizumab use, transplant centers are able to implement steroid-sparing or calcineurin minimization protocols. Unfortunately, the manufacturing costs have resulted in withdrawal of this agent from the market reducing the options for patients undergoing transplantation.

AREAS COVERED IN THIS REVIEW

This review will update the reader on recently published daclizumab studies in adult solid organ transplant recipients, focusing on comparative studies with other induction agents.

WHAT THE READER WILL GAIN

This paper will provide a summary of comparative studies between daclizumab and other induction therapies focusing on their efficacy and safety.

TAKE HOME MESSAGE

Novel applications, such as long-term use in combination with calcineurin-inhibitor dose reduction and its value in the treatment of acute or chronic rejection have yet to be explored. Since daclizumab has been withdrawn from the market, future IL-2 receptor blockade will have to be achieved with basiliximab, which is a chimeric, monoclonal antibody directed against the same epitope.

Immunosuppression in high-risk transplantation

PURPOSE OF REVIEW

Increasingly, transplant clinicians are faced with providing candidates with increased risks for poorer outcome with donor grafts that also carry higher risks of failure. Understanding the role of immunosuppressive management in these combinations of higher risks remains important for optimizing results.

RECENT FINDINGS

Few immunosuppressive protocols have been rigorously tested in the high-risk renal transplant setting. The two main risk categories accounted for in the trials are those ones that confer increased risks to renal function, usually carried by the donor organs, and those protocols defined by increased risk for immunological failure, mostly determined by recipient characteristics. The studied protocols generally involve reduction or avoidance of nephrotoxic drugs in the first case and use of lymphocyte-depleting agents in the case of increased immunological risk. In both scenarios, acceptable short-term results have been achieved. However, long-term results for high-risk transplants defined either by donor or recipient factors have yet to be reported.

SUMMARY

The lack of long-term data for optimizing the right immunosuppressive regimen for a given donor/recipient risk profile remains an ongoing challenge for researchers and clinicians alike.

Anti-interleukin-2 receptor antibodies-basiliximab and daclizumab-for the prevention of acute rejection in renal transplantation

The use of antibody induction after kidney transplantation has increased from 25% to 63% in the past decade and roughly one half of the induction agent used is anti-interleukin-2 receptor antibody (IL-2RA, ie, basiliximab or daclizumab). When combined with calcineurin inhibitor (CNI)-based immunosuppression, IL-2RAs have been shown to reduce the incidence of acute rejection, one of the predictors of poor graft survival, without increasing risks of infections and malignancies in kidney transplantation. For low-immunological-risk patients, IL-2RAs, as compared with lymphocyte-depleting antibodies, are equally efficacious and have better safety profiles. For high-risk patients, however, IL-2RAs may be inferior to lymphocyte-depleting antibodies for the prophylaxis of acute rejection. In an effort to reduce toxicities of other immunosuppressive medications without increasing the risk of acute rejection and chronic graft loss, IL-2RAs have often been combined with steroid- and CNI-sparing immunosuppression protocols. More data support the benefits of early steroid withdrawal with IL-2RA in low-risk patients, but preferred induction therapy for high-risk patients has yet to be determined. Although CNI-sparing protocols with IL-2RA may preserve renal function and improve long-term survival in selected patients, further studies are needed to identify those who benefit most from this strategy.

Steroid-free immunosuppression since 1999: 129 pediatric renal transplants with sustained graft and patient benefits

Despite early promising patient and graft outcomes with steroid-free (SF) immunosuppression in pediatric kidney transplant recipients, data on long-term safety and efficacy results are lacking. We present our single-center experience with 129 consecutive pediatric kidney transplant recipients on SF immunosuppression, with a mean follow-up of 5 years. Outcomes are compared against a matched cohort of 57 concurrent recipients treated with steroid-based (SB) immunosuppression. In the SF group, 87% of kidney recipients with functioning grafts remain corticosteroid-free. Actual intent-to-treat SF (ITT-SF) and still-on-protocol SF patient survivals are 96% and 96%, respectively, actual graft survivals for both groups are 93% and 96%, respectively and actual death-censored graft survivals for both groups are 97% and 99%, respectively. Unprecedented catch-up growth is observed in SF recipients below 12 years of age. Continued low rates of acute rejection, posttransplant diabetes mellitus (PTDM), hypertension and hyperlipidemia are seen in SF patients, with sustained benefits for graft function. In conclusion, extended enrollment and longer experience with SF immunosuppression for renal transplantation in low-risk children confirms protocol safety, continued benefits for growth and graft function, low acute rejection rates and reduced cardiovascular morbidity.

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.

Minimization of steroids in kidney transplantation

The goal of steroid minimization trials has been to minimize or eliminate steroid-related side-effects while simultaneously not increasing the rate of acute rejection (AR) and chronic graft loss. Early trials of late steroid withdrawal (> or =3 months post-transplant) were associated with significantly increased AR rates and late graft loss. More recent trials of rapid discontinuation of prednisone (RDP) (< or =7 days post-transplant) have been associated with little or no increase in AR rates and no difference in graft survival (versus maintenance prednisone). Of note, induction therapy appears to be important for success; however, it is not clear if any single maintenance protocol is superior. Intermediate-term follow-up (5-7 years) is now available for some randomized and nonrandomized trials; graft survival and renal function remain excellent. Most of these trials have been done in low immunologic risk recipients, but there are reports of success of RDP in children, black recipients, sensitized recipients, recipients with potentially recurring disease, and kidney-pancreas recipients. Of critical importance, steroid-related side-effects have been minimized. Steroid minimization protocols can clearly be recommended for low-risk patients; additional trials are necessary for those at higher risk. Additional research is also necessary on integrating calcineurin inhibitor minimization with steroid minimization.

Steroid elimination-who, when, how?

Steroids have numerous side effects, many occurring early posttransplantation with relatively low prednisone doses. Consequently, investigators have attempted steroid minimization or withdrawal. The first attempts at steroid minimization used early low-dose steroids and were associated with an increased rate of acute rejection episodes, late graft dysfunction, and graft loss. Subsequent studies, with cyclosporine-based immunosuppression, attempted steroid withdrawal late posttransplantation (>3 months) in highly selected, clinically well, and immunologically low-risk recipients. Again, steroid withdrawal was associated with an increased risk of acute rejection episodes and these episodes were associated with graft dysfunction and increased graft loss. The development of new powerful immunosuppressive agents has led to renewed attempts at late prednisone withdrawal. These also have been associated with increased late rejection risk. A more exciting innovation has been the attempts at rapid discontinuation ( Collapse

Key Words Collapse

MESH Headings

• Adrenal Cortex Hormones/adverse effects
• Antilymphocyte Serum/therapeutic use
• Clinical Trials as Topic
• Drug Administration Schedule
• Drug Therapy, Combination
• Graft Rejection/epidemiology
• Graft Rejection/prevention & control
• Graft Survival/drug effects
• Graft Survival/physiology
• Humans
• Immunosuppressive Agents/therapeutic use
• Kidney Transplantation/immunology
• Prednisone/adverse effects

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Grants

• P01 DK013083 NIDDK NIH HHS
• DK 13083 NIDDK NIH HHS

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Affiliation(s)

A J Matas Department of Surgery, University of Minnesota, Minneapolis, Minnesota 55455, USA.

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A prospective, randomized, double-blind, placebo-controlled multicenter trial comparing early (7 day) corticosteroid cessation versus long-term, low-dose corticosteroid therapy

OBJECTIVE

To compare outcomes with early corticosteroid withdrawal (CSWD) and chronic low dose corticosteroid therapy (CCS).

SUMMARY BACKGROUND DATA

Final, 5-year results from the first randomized, double-blind, placebo-controlled trial of early CSWD (at 7 days posttransplant) are presented.

METHODS

Adult recipients of deceased and living donor kidney transplants without delayed graft function were randomized to receive prednisone (5 mg/d after 6 months posttransplant) or CSWD. Blinding was maintained for 5 years. This clinical trial is registered at www.clinicaltrials.gov (NCT00650468).

RESULTS

Results in 386 patients CSWD (n = 191), CCS (n = 195) are presented (CSWD; CCS). No differences were observed at 5 years in the proportion of patients experiencing: primary end point (composite of death, graft loss, or moderate/severe acute rejection) (30/191 (15.7%); 28/195 (14.4%)), patient death (11/191(5.8%);13/195 (6.7%)), death-censored graft loss (11/191 (5.8%); 7/195(3.6%)), biopsy confirmed acute rejection (BCAR) (34/191 (17.8%); 21/195 (10.8%), P = 0.058), moderate/severe acute rejection (15/191 (7.9%); 12/195 (6.2%)). Kaplan Meier analyses of the primary end point and its components also showed no differences; but BCAR was higher with CSWD (P = 0.04). Increased BCAR episodes were primarily corticosteroid-sensitive Banff 1A rejections: the incidence of antibody-treated BCAR was similar between groups (11/191 (5.8%); 13/195 (6.7%)). No differences in renal function were observed at 5 years: mean serum creatinine (1.5 +/- 0.6; 1.5 +/- 0.7 mg/dL), or Cockroft Gault calculated creatinine clearance (58.6 +/- 19.7; 59.8 +/- 20.5 mL/min). CSWD was associated with improved serum triglycerides (evaluated by mean and median change from baseline) at all time points (except at 5 years measured by mean change). Weight change also demonstrated changes favoring CSWD (median change from baseline at 5 years: 5.1 vs. 7.7 kg, P = 0.05). New onset diabetes after transplant (NODAT) was similar with respect to proportions who required treatment (23/107 (21.5%)); 18/86 (20.9%); however, fewer CSWD patients required insulin for NODAT at 5 years (4/107 (3.7%)); 10/86 (11.6%), P = 0.049). Changes in HgA1c values (from baseline) were lower in CSWD patients at all time points except 4 years.

CONCLUSIONS

Early CSWD, compared with CCS, is associated with an increase in BCAR primarily because of mild, Banff 1A, steroid-sensitive rejection, yet provides similar long-term renal allograft survival and function. CSWD provides improvements in cardiovascular risk factors (triglycerides, NODAT requiring insulin, weight gain). Tacrolimus/MMF/antibody induction therapy allows early CSWD with results comparable to long-term low dose (5 mg/d) prednisone therapy.

Minimizing immunosuppression, an alternative approach to reducing side effects: objectives and interim result

Exceptionally low acute rejection rates and excellent graft survival can be achieved with cyclosporine and tacrolimus (CNI)-based immunosuppressive protocols that incorporate antiproliferative immunosuppressants and corticosteroids. However, despite short-term success, long-term attrition of graft function and side effects of immunosuppressive agents continue to be significant problems, leaving clinicians looking for possible interventions. CNI nephrotoxicity is but one of numerous factors that may contribute to long-term damage in transplant kidneys. Metabolic, cosmetic, and neuropsychiatric complications of steroids affect quality of life after transplantation. Newer immunosuppressive agents such as mycophenolate mofetil and sirolimus (Rapa) have raised the possibility of withdrawing or avoiding CNIs or steroids altogether. In this report we review studies that address either CNI or steroid minimization strategies and discuss their risks versus benefits. Given the accumulated experience to date, in our opinion the use of CNIs and steroids as part of immunosuppressive regimens remains the proven standard of care for renal transplant patients. The long-term safety and efficacy of CNI and steroid minimization strategies needs to be further validated in controlled clinical trials with adequate long-term follow-up.

Immunosuppression minimization in pediatric transplantation

The greatest benefit of immunosuppression minimization for children may lie in improving patient morbidity, by the elimination of the inherent side effects of steroid and calcineurin inhibitors (CNI). The newer generation of powerful induction and maintenance immunosuppressants offers an option for selected immunosuppression minimization strategies, some of which have been shown to also reduce graft morbidity. Steroid minimization and avoidance in single-center uncontrolled trials have shown early promise and the availability of data from an ongoing randomized, prospective, controlled trial of steroid avoidance in children will provide necessary data to support a practice change for steroid elimination in children. Calcineurin inhibitor minimization and addition of mycophenolate mofetil (MMF) or sirolimus have shown variable improvements in renal function, though suboptimal efficacy and safety with the currently proposed regimes have limited their application. Randomized, prospective studies of steroid and calcineurin inhibitor minimization and/or avoidance are warranted to clearly confirm the short and long-term safety and efficacy of alternative immunosuppression combinations. Linked pharmacokinetic and mechanistic studies within these trials will allow for optimizing drug dosing and monitoring. This article reviews published experience to date with steroid and calcineurin minimization in pediatric renal transplantation and discusses the risks and benefits of these approaches.

Sirolimus--challenging current perspectives

Sirolimus is a potent immunosuppressant drug with a novel mechanism of action. It inhibits the mammalian target of rapamycin (mTOR) and blocks the cell cycle of various cell types, including T- and B-lymphocytes. Sirolimus is widely used as a maintenance immunosuppressive agent in organ transplantation. Also, a potentially benefit of this valuable drug in some immunologic and malignant diseases is currently under scrutiny.Classical side effects: hematological (anaemia, leucopenia, thrombocytopenia), hypercholesterolemia, arthralgias, extremity oedema and impaired wound healing have been frequently associated with the use of sirolimus. Additionally with its increased use, transplant professionals are encountering a variety of previously unreported and potentially more severe side effects.Here, we review the most recent data on sirolimus unexpected side effects (with an emphasis on pulmonary and renal toxicity), its use in renal transplantation and its new potential therapeutic indications (chronic glomerulopathies, polycystic kidney disease, different types of cancer). A brief description of the current knowledge of sirolimus therapeutic drug monitoring, methods of analysis, pharmacokinetics and drug interactions with calcineurin inhibitors is also included.

Sirolimus pharmacokinetics in pediatric renal transplant recipients receiving calcineurin inhibitor co-therapy

We have previously reported sirolimus (SRL) pharmacokinetics (PK) in pediatric renal transplant recipients on a calcineurin inhibitor (CNI)-free protocol. We now report pediatric SRL PK in pediatric renal transplant patients receiving SRL + CNI. SRL was dosed to achieve target trough levels between 10 and 20 ng/mL. We performed 49 SRL PK profiles in pediatric renal transplant recipients receiving SRL in combination with either cyclosporine (CsA; 25 profiles), or tacrolimus (TCL; 24 profiles). Ten of the SRL + TCL profiles were obtained from children receiving SRL on a b.i.d. dosing regimen. All other SRL profiles were q.d. regimens. We calculated, the maximum concentration (C(max)), AUC, apparent clearance (aCL; dose/AUC) for dose in mg/m(2), and mean residence time (MRT). SRL levels were measured at 6 and 7 time points for b.i.d. and q.d. dosing, respectively. Regression analysis of SRL trough values vs. AUC showed good correlation in the SRL q.d. + CsA, SRL q.d. + TCL, and SRL b.i.d. + TCL groups (r(2) = 0.95, 0.68, and 0.44, respectively). SRL aCL corrected for body surface area was higher in children aged 0-5 yr receiving SRL with either CsA or TCL. SRL dosing schedule should be tailored to each patient. Higher SRL aCL may be present in younger children when administered with CNI.

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.