Calcineurin inhibitor minimization in the Symphony study: observational results 3 years after transplantation

Clinical impact of the CYP3A5 6986A>G allelic variant on kidney transplantation outcomes

AIM

Meta-analyses and large cohort studies provide confusing results on the association of the CYP3A5 6986A>G allelic variant and adverse outcomes in kidney transplant recipients under tacrolimus-based immunosuppressive regimen. A residual effect of CYP3A5 recipient genotype is unexpected if kidney transplant recipients have similar exposure of tacrolimus.

PATIENTS & METHODS

We have undertaken a population-based, observational study, to investigate all the consecutive patients who received a kidney transplant at the Necker hospital between 2005 and 2015, who were treated with tacrolimus and for whom the CYP3A5 genotype was available.

RESULTS & CONCLUSION

We analyzed 577 patients followed for up to 5 years. We found a significant association of CYP3A5 genotypes with tacrolimus daily dose as well as with tacrolimus dose-adjusted concentrations. We however found no association of CYP3A5 genotypes with histology scores on biopsies, measured renal function, biopsy-proven acute rejection episodes and graft survival.

1-Alpha, 25-dihydroxyvitamin D3 alters the pharmacokinetics of mycophenolic acid in renal transplant recipients by regulating two extrahepatic UDP-glucuronosyltransferases 1A8 and 1A10

Mycophenolic acid (MPA) is an important immunosuppressant broadly used in renal transplantation. However, the large inter-patient variability in mycophenolic acid (MPA) pharmacokinetics (PK) limits its use. We hypothesize that extrahepatic metabolism of MPA may have significant impact on MPA PK variability. Two intestinal UDP-glucuronosyltransferases 1A8 and 1A10 plays critical role in MPA metabolism. Both in silico and previous genome-wide analyses suggested that vitamin D (VD) may regulate intestinal UGT1A expression. We validated the VD response elements (VDREs) across the UGT1A locus with chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The impact of 1-alpha,25-dihydroxyvitamin D3 (D3) on UGT1A8 and UGT1A10 transcription and on MPA glucuronidation was tested in human intestinal cell lines LS180, Caco-2 and HCT-116. The correlation between transcription levels of VD receptor (VDR) and the two UGT genes were examined in human normal colorectal tissue samples (n = 73). PK alterations of MPA following the parent drug, mycophenolate mofetil (MMF), and D3 treatment was assessed among renal transplant recipients (n = 10). Our ChIP assay validate three VDREs which were further demonstrated as transcriptional enhancers with the luciferase assays. D3 treatment significantly increased transcription of both UGT genes as well as MPA glucuronidation in cells. The VDR mRNA level was highly correlated with that of both UGT1A8 and UGT1A10 in human colorectal tissue. D3 treatment in patients led to about 40% reduction in both AUC_0-12 and Cmax while over 70% elevation of total clearance of MPA. Our study suggested a significant regulatory role of VD on MPA metabolism and PK via modulating extrahepatic UGT activity.

Polyomavirus Reactivation and Immune Responses to Kidney-Specific Self-Antigens in Transplantation

Humoral immune responses against donor antigens are important determinants of long-term transplant outcomes. Reactivation of the polyomavirus BK has been associated with de novo antibodies against mismatched donor HLA antigens in kidney transplantation. The effect of polyomavirus reactivation (BK viremia or JC viruria) on antibodies to kidney-specific self-antigens is unknown. We previously reported excellent 5-year outcomes after minimization of immunosuppression for BK viremia and after no intervention for JC viruria. Here, we report the 10-year results of this trial (n=193) along with a nested case-control study (n=40) to explore associations between polyomavirus reactivation and immune responses to the self-antigens fibronectin (FN) and collagen type-IV (Col-IV). Consistent with 5-year findings, subjects taking tacrolimus, compared with those taking cyclosporin, had less acute rejection (11% versus 22%, P=0.05) and graft loss (9% versus 22%, P=0.01) along with better transplant function (eGFR 65±19 versus 50±24 ml/min per 1.73 m², P<0.001) at 10 years. Subjects undergoing immunosuppression reduction for BK viremia had 10-year outcomes similar to those without viremia. In the case-control study, antibodies to FN/Col-IV were more prevalent during year 1 in subjects with polyomavirus reactivation than in those without reactivation (48% versus 11%, P=0.04). Subjects with antibodies to FN/Col-IV had more acute rejection than did those without these antibodies (38% versus 8%, P=0.02). These data demonstrate the long-term safety and effectiveness of minimizing immunosuppression to treat BK viremia. Furthermore, these results indicate that polyomavirus reactivation associates with immune responses to kidney-specific self-antigens that may increase the risk for acute rejection through unclear mechanisms.

Immunosuppression for kidney transplantation: Where are we now and where are we going?

Advances in immunosuppression have propelled kidney transplantation from a scientific curiosity to the optimal treatment for patients with end stage kidney disease. Declining rates of acute rejection have led to improvements in short term kidney transplant survival, culminating in incrementally better long term patient and allograft outcomes. Contextualized around established immune-suppressing drug targets, this review summarizes the history of the clinical science and highlights the pivotal trials that have led to present-day treatment standards at the level of both individual agents and multidrug regimens for kidney recipients. Finally, recently approved and emerging therapies are discussed, with an emphasis on challenges faced by clinicians managing this increasingly complex patient population.

Mammalian Target of Rapamycin Inhibitors and Clinical Outcomes in Adult Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

Emerging evidence from recently published observational studies and an individual patient data meta-analysis shows that mammalian target of rapamycin inhibitor use in kidney transplantation is associated with increased mortality. Therefore, all-cause mortality and allograft loss were compared between use and nonuse of mammalian target of rapamycin inhibitors in patients from Australia and New Zealand, where mammalian target of rapamycin inhibitor use has been greater because of heightened skin cancer risk.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our longitudinal cohort study included 9353 adult patients who underwent 9558 kidney transplants between January 1, 1996 and December 31, 2012 and had allograft survival ≥1 year. Risk factors for all-cause death and all-cause and death-censored allograft loss were analyzed by multivariable Cox regression using mammalian target of rapamycin inhibitor as a time-varying covariate. Additional analyses evaluated mammalian target of rapamycin inhibitor use at fixed time points of baseline and 1 year.

RESULTS

Patients using mammalian target of rapamycin inhibitors were more likely to be white and have a history of pretransplant cancer. Over a median follow-up of 7 years, 1416 (15%) patients died, and 2268 (24%) allografts were lost. There was a higher risk of all-cause mortality with time-varying mammalian target of rapamycin inhibitor use (hazard ratio, 1.47; 95% confidence interval, 1.23 to 1.76) as well as in the fixed time model analyses comparing mammalian target of rapamycin inhibitor use at baseline (hazard ratio, 1.54; 95% confidence interval, 1.22 to 1.93) and 1 year (hazard ratio, 1.63; 95% confidence interval, 1.32 to 2.01). Time-varying mammalian target of rapamycin inhibitor use was associated with higher risk of death because of malignancy (hazard ratio, 1.37; 95% confidence interval, 1.09 to 1.71). There were no statistically significant differences in the risk of all-cause (hazard ratio, 0.98; 95% confidence interval, 0.85 to 1.12) and death-censored (hazard ratio, 0.85; 95% confidence interval, 0.69 to 1.03) allograft loss between the mammalian target of rapamycin inhibitor use and nonuse groups in the time-varying model as well as the fixed time models.

CONCLUSIONS

Mammalian target of rapamycin inhibitor use was associated with a higher risk of all-cause mortality but not allograft loss.

Mechanism of tacrolimus-induced chronic renal fibrosis following transplantation is regulated by ox-LDL and its receptor, LOX-1

Chronic renal allograft dysfunction (CRAD) is the most common cause of graft failure following renal transplantation. However, the underlying mechanisms remain to be fully elucidated. Immunosuppressants and hyperlipidemia are associated with renal fibrosis following long-term use. The present study aimed to determine the effects of tacrolimus (FK506) and lipid metabolism disorder on CRAD. In vitro and in vivo models were used for this investigation. Cells of the mouse proximal renal tubular epithelial cell strain, NRK-52E, were cultured either with oxidized low-density lipoprotein (ox-LDL), FK506, ox-LDL combined with FK506, or vehicle, respectively. Changes in cell morphology and changes in the levels of lectin-like ox-LDL receptor-1 (LOX-1), reactive oxygen species (ROS), hydrogen peroxide and fibrosis-associated genes were evaluated at 24, 48 and 72 h. In separate experiment, total of 60 Sprague-Dawley rats were divided randomly into four groups, which included a high-fat group, FK506 group, high-fat combined with FK506 group, and control group. After 2, 4 and 8 weeks, the serum lipid levels, the levels of ox-LDL, ROS, and the expression levels of transforming growth factor (TGF)-β1 and connective tissue growth factor were determined. The in vitro and in vivo models revealed that lipid metabolism disorder and FK506 caused oxidative stress and a fibrogenic response. In addition, decreased levels of LOX-1 markedly reduced the levels of TGF-β1 in the in vitro model. Taken together, FK506 and dyslipidemia were found to be associated with CRAD following transplantation.

Medical management of chronic kidney disease in the renal transplant recipient

PURPOSE OF REVIEW

An updated overview of the state-of-the-art approaches to the care of chronic kidney disease-related issues in renal transplant recipients.

RECENT FINDINGS

These include the impact of immunosuppression therapy on kidney function, the management of cardiovascular risk, metabolic bone disease, and hematologic complications, with a focus on the care of the patient with a failing allograft.

SUMMARY

A kidney transplant improves patient morbidity and mortality, but almost all transplant patients continue to have morbidity related to chronic kidney disease. It is increasingly clear that the provision of adequate immunosuppression is important to preserve allograft function. Recent studies have lent support to current guidelines for the management of cardiovascular risk factors in transplant patients. New data regarding the management of metabolic bone disease are sparse. Erythropoietin replacement may improve outcomes in transplant recipients, but the optimal target hemoglobin level is not known. Cessation of immunosuppression in the failed allograft carries the risk of rejection and allosensitization. New evidence suggests that nephrectomy may reduce mortality in patients with a failed allograft, but likely enhances sensitization in the patient awaiting retransplantation.

Roles of mTOR complexes in the kidney: implications for renal disease and transplantation

The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.

Indirect treatment comparison of belatacept versus tacrolimus from a systematic review of immunosuppressive therapies for kidney transplant patients

OBJECTIVE

End-stage renal disease is the final and irreversible stage in chronic kidney disease, leading to patient mortality, unless managed by dialysis or transplantation (the treatment of choice). This study aimed to compare a currently recommended immunosuppressive treatment, tacrolimus, against a newer treatment, belatacept, using indirect treatment comparison (ITC) techniques since no head-to-head randomized controlled trials (RCTs) comparing tacrolimus against belatacept currently exist.

METHODS

ITC was employed to calculate estimates for the relative risks and mean difference of tacrolimus against belatacept. The choice of the Bucher ITC model was driven by the available data and the simple indirect treatment comparison involving three treatments was considered appropriate.

RESULTS

The results of the indirect analysis showed no significant differences between belatacept and tacrolimus treatments for mortality and graft loss. The acute rejection rate was significantly lower with tacrolimus (Prograf* and Advagraf (*) ) compared with belatacept (0.22 [0.13, 0.39] to 0.44 [0.20, 0.99]).

CONCLUSIONS

The results of this systematic review and meta-analysis suggests that tacrolimus is significantly superior to belatacept in terms of acute rejection outcomes but comparable for graft and patient survival. Further research should include a properly designed clinical trial comparing tacrolimus against belatacept directly.

LIMITATIONS

These include variations in terms of clinical and design differences among the trials, weaknesses in the Bucher method and the lack of long-term clinical trial data with tacrolimus to compare with the recent long-term (7 years) belatacept trial data.

Effect of the Prophylactic Use of Proton-Pump Inhibitors on the Pattern of Gastrointestinal Symptoms in Patients Late After Kidney Transplant

OBJECTIVES

Although immunosuppressive drugs have been recognized as leading causes of gastrointestinal symptoms after kidney transplant, other widely used medications such as proton-pump inhibitors recently have been implicated. Our aim was to study the effects of chronic proton-pump inhibitor therapy on gastrointestinal symptoms in clinically stable patients late after kidney transplant.

MATERIALS AND METHODS

The study comprised 100 kidney transplant recipients (66 men and 34 women, mean age of 49 ± 12 y, mean time after transplant of 56 ± 46 mo). All patients completed the Gastrointestinal Symptoms Rating Scale and the Quality of Life Questionnaire SF-8 surveys.

RESULTS

The most commonly reported symptoms included borborygmus (27%), flatulence (23%), abdominal distension (18%), urgent need of defecation (17%), and heartburn, acid reflux, and eructation (13%). Proton-pump inhibitors were chronically used by 50% of patients and sporadically by 33%. Gastrointestinal Symptoms Rating Scale scores were higher in patients who used proton-pump inhibitors (mean score of 7.8 ± 5.5 vs 4.6 ± 3.0; P = .013). Total score of items representing diarrhea in the Gastrointestinal Symptoms Rating Scale (increased passage of stools, loose stools, urgent need of defecation, incomplete evacuation) was higher in patients treated with proton-pump inhibitors than in those not treated (2.3 ± 2.2 vs 1.3 ± 1.9; P = .04).

CONCLUSIONS

Chronic use of proton-pump inhibitors may increase the prevalence of gastrointestinal symptoms, particularly diarrhea, in patients late after kidney transplant.

A four-drug combination therapy consisting of low-dose tacrolimus, low-dose mycophenolate mofetil, corticosteroids, and mizoribine in living donor renal transplantation: A randomized study

OBJECTIVE

We compared a three-drug combination therapy (control group) consisting of tacrolimus, mycophenolate mofetil, and corticosteroids in living donor renal transplantation with a four-drug combination therapy (study group), in which the doses of tacrolimus and mycophenolate mofetil were halved and the immunosuppressive drug mizoribine was added, in order to determine whether the incidence rates of acute rejection after transplantation between the study group and the control group are similar, whether the study group regimen prevents the occurrence of calcineurin inhibitor-induced renal damage, and whether the study group regimen prevents adverse effects such as diarrhea caused by mycophenolate mofetil.

METHODS

We investigated the incidence of acute rejection, serum creatinine levels, and estimated glomerular filtration rate and the incidence of adverse effects such as diarrhea.

RESULTS

There was no significant difference between the two groups in the incidence of acute rejection. Renal function (estimated glomerular filtration rate and serum creatinine) was maintained in the control group whereas in the study group renal function gradually improved, with a statistical difference observed at 12 months. The incidence of gastrointestinal symptoms including diarrhea was significantly higher in the control group than in the study group. There was no significant difference in the incidence of cytomegalovirus infection and other adverse effects.

CONCLUSION

These results suggest the study group therapy is an effective regimen in preventing acute rejection and the deterioration of renal function. These results also show this therapy can reduce the incidence of adverse effects such as gastrointestinal symptoms.

Risk of post-transplantation diabetes mellitus is greater in South Asian versus Caucasian kidney allograft recipients

South Asians have increased risk for type 2 diabetes mellitus compared with Caucasians in the general population, but data for the development of post-transplantation diabetes mellitus (PTDM) is scarce. In this retrospective analysis, data was extracted from electronic patient records at a single centre (2004-2014). Caucasians were more likely to be male, with higher age and BMI than South Asians. Case-control matching was therefore undertaken to remove this bias, resulting in 102 recipient pairs. Median follow-up was 50 months (range 4-127 months). Matched groups had similar baseline characteristics, although South Asians compared with Caucasians received more deceased-donor kidneys (74% vs. 43%, respectively, P < 0.001) and were more likely to be CMV positive (77% vs. 43%, respectively, P < 0.001). PTDM incidence was significantly higher in South Asians versus Caucasians (35% vs. 10%, respectively, subhazard ratio 4.2 [95% CI: 2.1-8.5, P < 0.001]). Donor type had significant interaction with ethnicity, with the observed difference in PTDM rates between ethnicities most visible with receipt of deceased-donor kidneys. No significant difference was detected in allograft function, rejection episodes, adverse cardiovascular events or patient/graft survival. South Asians have increased risk of PTDM, especially recipients of deceased kidneys, and recognition of this allows appropriate patient counselling and development of targeted strategies.

The second report of the Nordic Pediatric Renal Transplantation Registry 1997-2012: More infant recipients and improved graft survivals

The NPRTSG has collected data on pediatric KTx since 1994. The registry archives information from all centers that perform pediatric KTx in Denmark, Finland, Norway, and Sweden and has 100% coverage. The first NPRTSG report was published in 1998 and was based on data collected in the 1982─1996 period. The present report provides data on 602 pediatric KTx in the Nordic countries from 1997 to 2012. Comparison of the patient demographics and one- and three-yr graft survivals between the two time cohorts revealed no significant change in the recipient and donor demographics. The number of transplantations increased by approximately 30%, doubling the recipients below the age of two yr. The use of Tac and mycophenolate as primary immunosuppression increased from practically 0% to 50% and 40%, respectively. The one- and three-yr graft survivals improved significantly (p < 0.001), especially among the youngest recipients with transplant from DD. In these patients, the one-yr survival improved from 70% to 94.6% and the three-yr graft survival from 60% to 94.6%, respectively. The improved graft survival may be at least partly due to changes in immunosuppression strategies, but also greater experience may also be of importance.

Different in vitro proliferation and cytokine-production inhibition of memory T-cell subsets after calcineurin and mammalian target of rapamycin inhibitors treatment

Calcineurin inhibitors (CNI) and mammalian target of rapamycin inhibitors (mTORi) are the main immunosuppressants used for long-term maintenance therapy in transplant recipients to avoid acute rejection episodes. Both groups of immunosuppressants have wide effects and are focused against the T cells, although different impacts on specific T-cell subsets, such as regulatory T cells, have been demonstrated. A greater knowledge of the impact of immunosuppression on the cellular components involved in allograft rejection could facilitate decisions for individualized immunosuppression when an acute rejection event is suspected. Memory T cells have recently gained focus because they might induce a more potent response compared with naive cells. The impact of immunosuppressants on different memory T-cell subsets remains unclear. In the present study, we have studied the specific impact of CNI (tacrolimus) and mTORi (rapamycin and everolimus) over memory and naive CD4(+) T cells. To do so, we have analysed the proliferation, phenotypic changes and cytokine synthesis in vitro in the presence of these immunosuppressants. The present work shows a more potent effect of CNI on proliferation and cytokine production in naive and memory T cells. However, the mTORi permit the differentiation of naive T cells to the memory phenotype and allow the production of interleukin-2. Taken together, our data show evidence to support the combined use of CNI and mTORi in transplant immunosuppression.

Tacrolimus reduction with everolimus addition for calcineurin inhibitor-induced arteriolopathy in kidney allografts

AIM

The aim of this study was to evaluate the effect of tacrolimus (TAC) reduction with everolimus (EVR) addition on the maintenance immunosuppression for the recipients with calcineurin inhibitor arteriolopathy (CNIA).

METHODS

This retrospective study consisted of 13 kidney allograft recipients who were found to have CNIA on protocol biopsy specimens. The time of intervention was 9-89 months. All the patients were on TAC, mycophenolate mofetil (MMF). 9 of 13 were on steroid. EVR was added and TAC dose was reduced. MMF dose was not changed. Revaluation biopsy was taken 12 months after the intervention. TAC trough levels (TACC0 , ng/mL), EVR trough levels (EVRC0 , ng/mL), estimated glomerular filtration rate (eGFR, mL/min), and urine protein per creatinine (uP/Cr, g/g creatinine) were compared before and 1 year after intervention. Changes in pathological findings and adverse events were also reviewed.

RESULTS

Aah scores improved in 5 patients. Aah scores did not change in the rest of the patients. No deterioration was observed. No improvement was seen in those with aah3. TACC0 reduced from 3.3 to 2.3. EVRC0 at revaluation was 4.1. eGFR improved from 44.3 to 49.8. uP/Cr slightly increased from 0.20 to 0.26. EVR was discontinued in 1 patient due to an adverse event. EVR dose was reduced in 5 patients due to adverse events.

CONCLUSION

TAC reduction with EVR addition improves CNIA histologically in selected cases.

Relationships among injury, fibrosis, and time in human kidney transplants

BACKGROUND

Kidney transplant biopsies offer an opportunity to understand the pathogenesis of organ fibrosis. We studied the relationships between the time of biopsy after transplant (TxBx), histologic fibrosis, diseases, and transcript expression.

METHODS

Expression microarrays from 681 kidney transplant indication biopsies taken either early (n = 282, <1 year) or late (n = 399, >1 year) after transplant were used to analyze the molecular landscape of fibrosis in relationship to histologic fibrosis and diseases.

RESULTS

Fibrosis was absent at transplantation but was present in some early biopsies by 4 months after transplant, apparently as a self-limited response to donation implantation injury not associated with progression to failure. The molecular phenotype of early biopsies represented the time sequence of the response to wounding: immediate expression of acute kidney injury transcripts, followed by fibrillar collagen transcripts after several weeks, then by the appearance of immunoglobulin and mast cell transcripts after several months as fibrosis appeared. Fibrosis in late biopsies correlated with injury, fibrillar collagen, immunoglobulin, and mast cell transcripts, but these were independent of time. Pathway analysis revealed epithelial response-to-wounding pathways such as Wnt/β-catenin.

CONCLUSION

Fibrosis in late biopsies had different associations because many kidneys had potentially progressive diseases and subsequently failed. Molecular correlations with fibrosis in late biopsies were independent of time, probably because ongoing injury obscured the response-to-wounding time sequence. The results indicate that fibrosis in kidney transplants is driven by nephron injury and that progression to failure reflects continuing injury, not autonomous fibrogenesis.

TRIAL REGISTRATION

INTERCOM study (www.clinicalTrials.gov; NCT01299168).

FUNDING

Canada Foundation for Innovation and Genome Canada.

Sirolimus-Based Immunosuppressive Regimens in Renal Transplantation: A Systemic Review

Sirolimus (SRL)-based immunosuppressive regimens have been used for preventing rejection after kidney transplantation. This review analyzes their merits and demerits compared with other conventional regimes from the aspects of acute rejection rate, graft function, as well as patient/graft survival rates. In general, SRL is mostly recommended to be used as conversion therapy from calcineurin inhibitor (CNI) after kidney transplantation in most studies. Minimization or withdrawal of cyclosporine A (CsA) could also be considered when it was combined with SRL. SRL can replace mycophenolate mofetil (MMF), and the CNI dose should be reduced appropriately in this setting. Quadruple maintenance regimens containing SRL need future study to clarify their superiority. De novo use of low-dose CNI combined with SRL has no apparent merits and thus is not recommended. De novo use of standard-dose CNI combined with SRL followed by maintenance, de novo use of CNI-free regimens, as well as SRL use in delayed graft function (DGF) patients who spare antibody induction and postpone CNI administration should also be avoided. SRL supports steroids withdrawal after kidney transplantation, and SRL combined with tacrolimus is recommended in this setting. Loading dose is recommended when initiating SRL treatment and its trough blood level should be routinely monitored.

Combining cytochrome P-450 3A4 modulators and cyclosporine or everolimus in transplantation is successful

AIM

To describe the long term follow-up of kidney allograft recipients receiving ketoconazole with calcineurin inhibitors (CNI) alone or combined with everolimus.

METHODS

This is an open-label, prospective observational clinical trial in low immunologic risk patients who, after signing an Institutional Review Board approved consent form, were included in one of two groups. The first one (n = 59) received everolimus (target blood level, 3-8 ng/mL) and the other (n = 114) azathioprine 2 mg/kg per day or mycophenolate mofetyl (MMF) 2 g/d. Both groups also received tapering steroids, the cytochrome P-450 3A4 (CYP3A4) modulator, ketoconazole 50-100 mg/d, and cyclosporine with C0 targets in the everolimus group of 200-250 ng/mL in 1 mo, 100-125 ng/mL in 2 mo, and 50-65 ng/mL thereafter, and in the azathioprine or MMF group of 250-300 ng/mL in 1 mo, 200-250 ng/mL in 2 mo, 180-200 ng/mL until 3-6 mo, and 100-125 ng/mL thereafter. Clinical visits were performed monthly the first year and quarterly thereafter by treating physicians and all data was extracted by the investigators.

RESULTS

The clinical characteristics of these two cohorts were similar. During the follow up (66 + 31 mo), both groups showed comparable clinical courses, but the biopsy proven acute rejection rate during the full follow-up period seemed to be lower in the everolimus group (20% vs 36%; P = 0.04). The everolimus group did not show a higher surgical complication rate than the other group. By the end of the follow-up period, the everolimus group tended to show a higher glomerular filtration rate. Nevertheless, we found no evidence of a consistent negative slope of the temporal allograft function estimated by the modification of the diet in renal disease formula in any of both groups. At 6 years of follow-up, the uncensored and death-censored graft survivals were 91% and 93%, and 91% and 83% in the everolimus plus cyclosporine, and cyclosporine alone groups, respectively. The addition of ketoconazole saved 80% of cyclosporine and 56% of everolimus doses.

CONCLUSION

Combining CYP3A4 modulators with CNI or mammalian target of rapamycin inhibitor, in low immunological risk kidney transplant recipients is feasible, effective, safe and affordable even in the long term.

Efficacy and safety of tacrolimus compared with ciclosporin-A in renal transplantation: 7-year observational results

The European Tacrolimus versus Ciclosporin-A Microemulsion (CsA-ME) Renal Transplantation Study demonstrated that tacrolimus decreased acute rejection rates at 6 months. Primary endpoints of this investigator-initiated, observational 7-year follow-up study were acute rejection rates, patient and graft survival rates, and a composite endpoint (BPAR, graft loss, and patient death). We analyzed data from the original intent-to-treat population (n = 557; 286 tacrolimus, 271 CsA-ME). A total of 237 tacrolimus and 208 CsA-ME patients provided data. At 7 years, Kaplan-Meier estimated rates of patients free from BPAR were 77.1% in the tacrolimus arm and 59.9% in the CsA-ME arm, graft survival rates amounted to 82.6% and 80.6%, and patient survival rates to 89.9% and 88.1%. Estimated combined endpoint-free survival rates were 60.2% in the tacrolimus arm and 47.0% in the CsA-ME arm (P = <0.0001). A higher number of patients from the CsA-ME arm crossed over to tacrolimus during 7 year follow-up: 19.7% vs. 7.9% (P = <0.002). More patients in the tacrolimus group stopped steroids and received immunosuppressive monotherapy. Significantly, more CsA-ME patients received lipid-lowering medication and experienced cosmetic and cardiovascular adverse events. Tacrolimus-treated renal transplant recipients had significantly higher combined endpoint-free survival rates mainly driven by lower acute rejection rates despite less immunosuppressive medication at 7 years.

Sirolimus versus tacrolimus in kidney transplant recipients receiving mycophenolate mofetil and steroids: focus on acute rejection, patient and graft survival

The study aims to conduct a meta-analysis of randomized controlled trials to compare the efficacy of tacrolimus (TAC)/mycophenolate mofetil (MMF)/corticosteroids (CSs) with sirolimus (SRL)/MMF/CSs in renal transplant recipients: Research 2 databases, PubMed, and Web of Science, selecting relevant articles. Data were selected for acute rejection and patient and graft survival. Statistical value relative risk (RR) and 95% confidence intervals (CIs) were recorded. Six randomized controlled trials involving 885 patients were included. There was a significant difference in acute rejection (P = 0.001, RR = 1.69, 95% CI, 1.23-2.34). Two groups, patient survival (P = 0.96, RR = 1.02, 95% CI, 0.54-1.91) and graft survival (P = 0.09, RR = 1.56, 95% CI, 0.93-2.60), had no statistical difference. Acute rejection by those taking SRL/MMF/CSs is worse than those taking TAC/MMF/CSs. Patient and graft survival in TAC/MMF/CSs is similar to that in SRL/MMF/CSs.

Advances in pharmacotherapy to treat kidney transplant rejection

INTRODUCTION

Current immunosuppressive combination therapy provides excellent prevention of T-cell-mediated rejection following renal transplantation; however, antibody-mediated rejection remains of high concern and accounts for a large number of long-term allograft losses. The recent development of protocol biopsies resulted in the definition of subclinical rejection (SCR), showing histologic evidence for rejection but unremarkable clinical course.

AREAS COVERED

This review describes the current knowledge and evidence of pharmacotherapy to treat kidney allograft rejections and covers SCR treatment options. Each substance is analyzed with regard to its classical indication and further discussed for the treatment of other forms of rejection.

EXPERT OPINION

Despite a lack of randomized trials, early acute T-cell-mediated rejection can be treated effectively in most cases without graft loss. The necessity to treat SCR is currently unclear. Due to a lack of effective therapies, new treatment approaches for antibody-mediated rejection are an urgent medical need to improve long-term outcomes. Future research should aim to better define pathophysiology and histology, stratify risk, and develop rational treatment strategies from randomized controlled trials, in order to establish the value of novel therapies in the arsenal of rejection pharmacotherapy. However, the effective prevention of rejection with minimal side effects still remains the goal in immunosuppression.

Current trends in immunosuppression following organ transplantation in children

PURPOSE OF REVIEW

To highlight the current trends in immunosuppression and their application to paediatric transplantation informed by the systematic reviews and randomized controlled trials: new induction agents, steroid avoidance, calcineurin minimization and desensitization protocols.

RECENT FINDINGS

Newer induction agents, belatacept and alemtuzumab, are associated with serious side-effects, and interleukin-2 receptor antagonists remain the preferred agents in children. Steroid-free regimens may improve growth and, compared with steroid-containing regimens, have similar short to medium term graft survival, although long-term outcomes are uncertain. Mammalian target of rapamycin inhibitors, sirolimus and everolimus, when used in recipients as primary immunosuppression to avoid calcineurin exposure, results in poorer graft survival. Although desensitization is being performed more frequently, the relative benefits and harms of regimens used are uncertain.

SUMMARY

There is growing evidence for the use of steroid-free immunosuppression regimens in children to maximize growth. Further trials with a focus on long-term graft survival are needed to establish the role of desensitization protocols in organ transplantation in children.

How to handle missed or delayed doses of tacrolimus in renal transplant recipients? A pharmacokinetic investigation

Every transplant patient will, at least occasionally, miss immunosuppressive drug doses or take them outside the prescribed times. This study aims at quantifying the impact of poor execution on tacrolimus exposure in renal transplant patients. Validated pharmacokinetic tools applied in clinical setting were used to simulate the steady-state pharmacokinetic profiles of the drug when given as the immediate-release formulation to renal transplant patients, being CYP3A5 expressors or not, and who have reached either a standard or a minimized exposure. Situations of interruption due to a missed or delayed dose were simulated and the impact on drug exposure was explored. In case of a missed dose, it was observed that: (i) a single forgotten dose can greatly impact exposure: up to 49% decrease for tacrolimus trough concentration and 70% for AUC0-12 h in patients with the highest clearance values; (ii) patients with a minimized exposure are the most affected by a missed dose; and (iii) a dose of 1.5 times the usual dose may be recommended after a total dose oversight. Considering that intra-patient exposure variability is a predictive factor of poor graft outcome, these modeling results may serve as recommendations for patients, both preventively and in response to their questions.

Transplant patient classification and tacrolimus assays: more evidence of the need for assay standardization

BACKGROUND

A global tacrolimus proficiency study recently showed clinically significant variability between laboratories, the inability of a common calibrator to harmonize methods, and differences in patient classification depending on the test method. The authors evaluated (1) the effect of a change in methodology on patient classification based on tacrolimus blood concentration and (2) the ability of 2 methods to position the concentration in a given specimen within the correct range.

METHODS

A total of 839 consecutive samples were analyzed at The Rogosin Institute and New York Presbyterian Hospital for routine tacrolimus monitoring over 30 days. Concordance analysis between the methods was performed covering dosage target ranges of 8-10, 6-8, 4-6 ng/mL currently used at our center. Six Sigma Metrics were applied to statistically evaluate the discordance rate.

RESULTS

Deming regression comparing liquid chromatography-tandem mass spectrometry and immunoassay yielded y = 0.927x - 0.24; 95% confidence interval, 0.903-0.951; R = 0.875; n = 839. There were 310 pairs (37%) discordant by 1, 21 (2.5%) discordant by 2, and 4 (0.5%) discordant by 3 therapeutic ranges. Surprisingly, 40% of patient samples were discordant when therapeutic ranges were 2 ng/mL wide. This discordant rate is equivalent to 1.7 Sigma and falls far below the minimum acceptable threshold of 3 Sigma.

CONCLUSIONS

Both methods are capable of measuring tacrolimus in the clinically relevant range between 1 and 10 ng/mL, yet 40% of the samples were discordant with an unacceptable Sigma level. Standardization of tacrolimus assays will mitigate this issue.

Cost-effectiveness of modern mTOR inhibitor based immunosuppression compared to the standard of care after renal transplantation in Germany

OBJECTIVES

Standards of immunosuppression in renal transplantation have changed dynamically in recent years. We here provide a refined advanced pharmacoeconomic model which uses state-of-the-art methods including a mixed treatment comparison (MTC) analysis. The aim was to assess the cost-effectiveness of current immunosuppressive therapy regimens (TR): "sirolimus + early withdrawal of cyclosporine + steroids" (TR1), "sirolimus-early transition" (TR2), "everolimus-early transition" (TR3) and "tacrolimus low dose + mycophenolate mofetil (MMF) + steroids" (TR4).

METHODS

An up-to-date Markov model with current source data was employed to assess the cost-effectiveness of modern immunosuppressive regimens over 12-month and 10-year time periods. Transition probabilities for the occurrence of events for the first year were based on an MTC analysis. The robustness of the model was tested in extensive sensitivity analyses.

RESULTS

Within the 12-month time period TR2 yields the highest life years (0.987 LY), generating costs of 17,500 <euro>. In terms of years with functioning graft (FG), TR4 yields the best efficacy over the 12-month model duration (0.970 years with FG). For the 10-year time period, TR2 yields the lowest costs (107,246 <euro>) and dominates both TR3 and TR1, as it is simultaneously more effective. Within the 10-year model duration, TR4 reaches slightly higher effects compared with TR2 (6.493 vs. 6.474 LY) resulting in an incremental cost-effectiveness ratio of 387,684 <euro> per LY gained.

CONCLUSIONS

The early transition to sirolimus provides long-term efficiency results comparable with a tacrolimus-based regimen, which represents a common treatment standard after kidney transplantation. Both are superior to other investigated immunosuppressive regimens.

Characterization of clinical and genetic risk factors associated with dyslipidemia after kidney transplantation

We determined the prevalence of dyslipidemia in a Japanese cohort of renal allograft recipients and investigated clinical and genetic characteristics associated with having the disease. In total, 126 patients that received renal allograft transplants between February 2002 and August 2011 were studied, of which 44 recipients (34.9%) were diagnosed with dyslipidemia at 1 year after transplantation. Three clinical factors were associated with a risk of having dyslipidemia: a higher prevalence of disease observed among female than male patients (P = 0.021) and treatment with high mycophenolate mofetil (P = 0.012) and prednisolone (P = 0.023) doses per body weight at 28 days after transplantation. The genetic association between dyslipidemia and 60 previously described genetic polymorphisms in 38 putative disease-associated genes was analyzed. The frequency of dyslipidemia was significantly higher in patients with the glucocorticoid receptor (NR3C1) Bcl1 G allele than in those with the CC genotype (P = 0.001). A multivariate analysis revealed that the NR3C1 Bcl1 G allele was a significant risk factor for the prevalence of dyslipidemia (odds ratio = 4.6; 95% confidence interval = 1.8–12.2). These findings may aid in predicting a patient's risk of developing dyslipidemia.

The need for minimization strategies: current problems of immunosuppression

New immunosuppressants and the better use of immunosuppressant combination therapy have led to significant improvements in renal allograft outcomes over the last decades. Yet, despite dramatic reduction in rejection rates and improvement in 1-year graft survival, long-term graft attrition rates remained rather constant. Current immunosuppressant combinations are frequently leading to overimmunosuppression and are increasing cardiovascular risk. Importantly, calcineurin inhibitors are nephrotoxic, contribute to cardiovascular risk and chronic allograft dysfunction. Furthermore, immunosuppressant-associated toxicities aggravate immune-mediated nephron injury and side effects lead to nonadherence, an identified important reason for late acute and chronic antibody-mediated rejections. The frequent development of a chronic humoral response indicates rather insufficient immunosuppression of current combinations than simple under-immunosuppression. While there is no evidence that increasing immunosuppressive doses will improve outcomes or reduce de novo HLA-antibody formation, there is clear evidence that adequate minimization strategies will reduce side effect burden. Because of low rejection risk, but frequent side effects, drug minimization is particularly relevant for the many maintenance patients. In summary, new therapeutic strategies need to be developed from adequately powered clinical trials for reduction of the many side effects of immunosuppressants. Such evidence-based and time-dependent immunosuppressive minimization strategies are needed to achieve better long-term outcomes in the future.

Now or never? The case for cell-based immunosuppression in kidney transplantation

By exploiting mechanisms of immunological regulation against donor alloantigen, it may be possible to reduce the dependence of kidney transplant recipients upon calcineurin inhibitor-based maintenance immunosuppression. One means to strengthen regulatory responses is treating recipients with preparations of regulatory cells obtained by ex vivo manipulation. This strategy, which is a well-established experimental method, has been developed to the point that early-phase clinical trials in kidney transplantation are now feasible. Cell-based therapies represent a radical departure from conventional treatment, so what grounds are there for this new approach? This article offers a three-part justification for trialing cell-based therapies in kidney transplantation: first, a clinical need for alternatives to standard immunosuppression is identified, based on the inadequacies of calcineurin inhibitor-based regimens in preventing late allograft loss; second, a mechanistic explanation of how cell-based therapies might address this clinical need is given; and third, the possible benefit to patients is weighed against the potential risks of cell-based immunosuppressive therapy. It is concluded that the safety of cell-based immunosuppressive therapy will not be greatly improved by further basic scientific and preclinical development. Only trials in humans can now tell us whether cell-based therapy is likely to benefit kidney transplant recipients, but these should be conservative in design to minimize any potential harm to patients.

A randomized 2×2 factorial trial, part 1: single-dose rabbit antithymocyte globulin induction may improve renal transplantation outcomes

Supplemental digital content is available in the text.

Background

We conducted a randomized and unblinded 2×2 sequential-factorial trial, composed of an induction arm (part 1) comparing single-dose (SD) versus divided-dose rabbit antithymocyte globulin (rATG), and a maintenance arm (part 2) comparing tacrolimus minimization versus withdrawal. We report the long-term safety and efficacy of SD-rATG induction in the context of early steroid withdrawal and tacrolimus minimization or withdrawal.

Methods

Patients (n=180) received 6 mg/kg rATG, SD or four alternate-day doses (1.5 mg/kg/dose), with early steroid withdrawal and tacrolimus or sirolimus maintenance. After 6 months targeted maintenance levels were tacrolimus, 2 to 4 ng/mL and sirolimus, 4 to 6 ng/mL or, if calcineurin inhibitor–withdrawn, sirolimus 8 to 12 ng/mL with mycophenolate mofetil 2 g two times per day. Primary endpoints were renal function (abbreviated modification of diet in renal disease) and chronic graft histopathology (Banff). Secondary endpoints included patient survival, graft survival, biopsy-proven rejection, and infectious or noninfectious complications.

Results

Follow-up averaged longer than 4 years. Tacrolimus or sirolimus and mycophenolate mofetil exposure was identical between groups. The SD-rATG associated with improved renal function (2-36 months; P<0.001) in deceased donor recipients. The SD-rATG associated with quicker lymphocyte, CD4 T cell, and CD4-CD8 recovery and fewer infections. Cox multivariate hazard modeling showed divided-dose–rATG (P=0.019), deceased donor (P=0.003), serious infection (P=0.0.018), and lower lymphocyte count (P=0.001) associated with increased mortality. Patients with all four covariates showed a 27-fold increased likelihood of death (P=0.00002). Chronic graft histopathology, rejection rates, and death-censored graft survival were not significantly different between groups.

Conclusion

The SD-rATG induction improves the 3-year renal function in recipients of deceased donor kidneys. This benefit, along with possibly improved patient survival and fewer infections suggest that how rATG is administered may impact its efficacy and safety.

Calcineurin inhibitor-sparing regimens based on mycophenolic acid after kidney transplantation

The use of calcineurin inhibitors (CNIs) has dramatically reduced the number of acute rejections and improved kidney allograft survival. However, CNIs can also cause kidney damage and several adverse events. This has prompted transplant physicians to use CNI-sparing regimens. CNI withdrawal, minimization, or avoidance protocols have been conducted using mycophenolic acid (MPA), and/or mammalian-target-of-rapamycin inhibitors, and/or belatacept. Herein, we review the outcomes of minimizing, withdrawing, or avoiding CNIs when giving mycophenolic acid to de novo and maintenance kidney transplant patients. Protocols on CNI withdrawal, when based on MPA without mammalian-target-of-rapamycin inhibitors (mTORi) or belatacept, in de novo and maintenance kidney transplant patients, are associated with an increased risk of acute rejection. Consequently, these strategies have been abandoned and are not recommended. Protocols on CNI minimization show a beneficial impact of kidney function and acceptable acute rejection rates mainly in patients who have been recipients of a graft for >3-5 years. However, no significant improvement to graft survival has been observed.

Understanding the Perceived Threat of the Risk of Graft Rejections: A Middle-Range Theory

From a clinical viewpoint, graft rejection is one of the greatest threats faced by an organ transplant recipient (OTR). We propose a middle-range theory (MRT) of Perceived Threat of the Risk of Graft Rejection (PTRGR) as a contribution to the practice of transplant nursing. It could also apply to the detection of risky protective behavior, that is, isolation, avoidance, or non-adherence. The proposed MRT covers the following concepts and the relationship between them: transplant care needs, threat reducing interventions, intervening variables, level of PTRGR, protective strategies, and evidence-based practice. Parts of this theory have been empirically tested and support the suggested relationship between some of the concepts. Further tests are needed to strengthen the theoretical links. The conceptual framework might serve as a guide for transplant nurses in their efforts to promote post-transplant health and reduce threat-induced emotions.

FR104, an antagonist anti-CD28 monovalent fab' antibody, prevents alloimmunization and allows calcineurin inhibitor minimization in nonhuman primate renal allograft

Selective targeting of CD28 might represent an effective immunomodulation strategy by preventing T cell costimulation, while favoring coinhibition since inhibitory signals transmitted through CTLA-4; PD-L1 and B7 would not be affected. We previously showed in vitro and in vivo that anti-CD28 antagonists suppress effector T cells while enhancing regulatory T cell (Treg) suppression and immune tolerance. Here, we evaluate FR104, a novel antagonist pegylated anti-CD28 Fab' antibody fragment, in nonhuman primate renal allotransplantation. FR104, in association with low doses of tacrolimus or with rapamycin in a steroid-free therapy, prevents acute rejection and alloantibody development and prolongs allograft survival. However, when FR104 was associated with mycophenolate mofetil and steroids, half of the recipients rejected their grafts prematurely. Finally, we observed an accumulation of Helios-negative Tregs in the blood and within the graft after FR104 therapy, confirmed by Treg-specific demethylated region DNA analysis. In conclusion, FR104 reinforces immunosuppression in calcineurin inhibitor (CNI)-low or CNI-free protocols, without the need of steroids. Accumulation of intragraft Tregs suggested the promotion of immunoregulatory mechanisms. Selective CD28 antagonists might become an alternative CNI-sparing strategy to B7 antagonists for kidney transplant recipients.

Conversion to mycophenolate mofetil from azathioprine shows significant positive effect on graft function in long-term past-kidney transplantation stable-state patients

OBJECTIVES

A number of reports have shown that the efficacy of mycophenolate mofetil (MMF) is superior to that of azathioprine (AZP) for long-term kidney allograft survival. We conducted a retrospective single-center study to evaluate renal function more than 2 years after conversion from AZP to MMF in kidney transplant recipients several years after transplantation.

METHODS

AZP was converted to MMF in 51 recipients at 17.0 ± 0.8 years after kidney transplantation who were followed up for more than 2 years after conversion. Estimated glomerular filtration rate (eGFR) was determined using the Formula of the Japanese Society of Nephrology.

RESULTS

The eGFR was significantly greater at 1 year before conversion (41.72 ± 1.91 mL/min/1.73 m(2)) as compared with the day of conversion (39.04 ± 1.82 mL/min/1.73 m(2); P < .05). After conversion, eGFR plateaued to 39.30 ± 2.01 mL/min/1.73 m(2) at 1 year and 38.24 ± 2.42 mL/min/1.73 m(2) at 2 years after conversion. The average eGFR slopes were -2.96 ± 0.36 mL/min/1.73 m(2) per year for AZP and 1.22 ± 0.10 mL/min/1.73 m(2) per year for MMF (P < .0001). Cyclosporine (CSA) was reduced from 176 ± 9.3 to 165 ± 9.8 mg/d (P = .0394) after the switch, whereas the CSA trough level was increased from 77.3 ± 6.6 to 118 ± 9.8 ng/mL (P = .0017). Furthermore, the daily dose of tacrolimus (TAC) was decreased from 3.5 ± 0.3 to 3.1 ± 0.3 mg/d (P = .0083).

CONCLUSIONS

Our findings demonstrated the safety of conversion from AZP to MMF even in the patients who underwent renal transplantation several years prior. In addition, these short-term results indicated the improvement in allograft function following conversion.

Tacrolimus therapeutic drug monitoring and pediatric renal transplant graft outcomes

Predose monitoring of tacrolimus levels is standard practice in the care of pediatric renal transplant patients. This is despite a paucity of data investigating the ideal target range in children, and controversy as to whether tacrolimus levels correlate with renal transplant outcomes. We performed a retrospective cohort analysis of 48 renal transplant patients at a single Canadian pediatric transplant center following the initiation of a tacrolimus-mycophenolate-prednisone-based IS protocol. We analyzed the relationship of graft function, as defined by GFR up to five yr post-transplant, to the preceding mean tacrolimus level. There was no significant correlation between absolute GFR and mean tacrolimus levels (r = 0.206, p = 0.38). However, a higher mean tacrolimus level, particularly ≥10 ng/mL in the first three months after transplantation, was associated with a slower rate of decline in GFR with time (r = 0.608, p = 0.004) and with a less likelihood of developing CKD five yr after transplant. We suggest that the optimal target range for tacrolimus levels may be at the upper end of what is currently practiced and that further research to validate these findings would be useful.

Belatacept for kidney transplant recipients

BACKGROUND

Most people who receive a kidney transplant die from either cardiovascular disease or cancer before their transplant fails. The most common reason for someone with a kidney transplant to lose the function of their transplanted kidney necessitating return to dialysis is chronic kidney transplant scarring. Immunosuppressant drugs have side effects that increase risks of cardiovascular disease, cancer and chronic kidney transplant scarring. Belatacept may provide sufficient immunosuppression while avoiding unwanted side effects of other immunosuppressant drugs. However, high rates of post-transplant lymphoproliferative disease (PTLD) have been reported when belatacept is used in particular kidney transplant recipients at high dosage.

OBJECTIVES

1) Compare the relative efficacy of belatacept versus any other primary immunosuppression regimen for preventing acute rejection, maintaining kidney transplant function, and preventing death. 2) Compare the incidence of several adverse events: PTLD; other malignancies; chronic transplant kidney scarring (IF/TA); infections; change in blood pressure, lipid and blood sugar control. 3) Assess any variation in effects by study, intervention and recipient characteristics, including: differences in pre-transplant Epstein Barr virus serostatus; belatacept dosage; and donor-category (living, standard criteria deceased, or extended criteria deceased).

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 1 September 2014 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCT) that compared belatacept versus any other immunosuppression regimen in kidney transplant recipients were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data for study quality and transplant outcomes and synthesized results using random effects meta-analysis, expressed as risk ratios (RR) and mean differences (MD), both with 95% confidence intervals (CI).  Subgroup analyses and univariate meta-regression were used to investigate potential heterogeneity.

MAIN RESULTS

We included five studies that compared belatacept and calcineurin inhibitors (CNI) that reported data from a total of 1535 kidney transplant recipients. Of the five studies, three (478 participants) compared belatacept and cyclosporin and two (43 recipients) compared belatacept and tacrolimus. Co-interventions included basiliximab (4 studies, 1434 recipients); anti-thymocyte globulin (1 study, 89 recipients); alemtuzumab (1 study, 12 recipients); mycophenolate mofetil (MMF, 5 studies, 1509 recipients); sirolimus (1 study, 26 recipients) and prednisone (5 studies, 1535 recipients).Up to three years following transplant, belatacept and CNI-treated recipients were at similar risk of dying (4 studies, 1516 recipients: RR 0.75, 95% CI 0.39 to 1.44), losing their kidney transplant and returning to dialysis (4 studies, 1516 recipients: RR 0.91, 95% CI 0.61 to 1.38), and having an episode of acute rejection (4 studies, 1516 recipients: RR 1.56, 95% CI 0.85 to 2.86). Belatacept-treated kidney transplant recipients were 28% less likely to have chronic kidney scarring (3 studies, 1360 recipients: RR 0.72, 95% CI 0.55 to 0.94) and also had better graft function (measured glomerular filtration rate (GFR) (3 studies 1083 recipients): 10.89 mL/min/1.73 m², 95% CI 4.01 to 17.77; estimated GFR (4 studies, 1083 recipients): MD 9.96 mL/min/1.73 m², 95% CI 3.28 to 16.64) than CNI-treated recipients. Blood pressure was lower (systolic (2 studies, 658 recipients): MD -7.51 mm Hg, 95% CI -10.57 to -4.46; diastolic (2 studies, 658 recipients): MD -3.07 mm Hg, 95% CI -4.83 to -1.31, lipid profile was better (non-HDL (3 studies 1101 recipients): MD -12.25 mg/dL, 95% CI -17.93 to -6.57; triglycerides (3 studies 1101 recipients): MD -24.09 mg/dL, 95% CI -44.55 to -3.64), and incidence of new-onset diabetes after transplant was reduced by 39% (4 studies (1049 recipients): RR 0.61, 95% CI 0.40 to 0.93) among belatacept-treated versus CNI-treated recipients.Risk of PTLD was similar in belatacept and CNI-treated recipients (4 studies, 1516 recipients: RR 2.79, 95% CI 0.61 to 12.66) and was no different among recipients who received different belatacept dosages (high versus low dosage: ratio of risk ratios (RRR) 1.06, 95% CI 0.11 to 9.80, test of difference = 0.96) or among those who were Epstein Barr virus seronegative compared with those who were seropositive before their kidney transplant (seronegative versus seropositive; RRR 1.49, 95% CI 0.15 to 14.76, test for difference = 0.73).The belatacept dose used (high versus low), type of donor kidney the recipient received (extended versus standard criteria) and whether the kidney transplant recipient received tacrolimus or cyclosporin made no difference to kidney transplant survival, incidence of acute rejection or estimated GFR. Selective outcome reporting meant that data for some key subgroup comparisons were sparse and that estimates of the effect of treatment in these groups of recipients remain imprecise.

AUTHORS' CONCLUSIONS

There is no evidence of any difference in the effectiveness of belatacept and CNI in preventing acute rejection, graft loss and death, but treatment with belatacept is associated with less chronic kidney scarring and better kidney transplant function. Treatment with belatacept is also associated with better blood pressure and lipid profile and a lower incidence of diabetes versus treatment with a CNI. Important side effects (particularly PTLD) remain poorly reported and so the relative benefits and harms of using belatacept remain unclear. Whether short-term advantages of treatment with belatacept are maintained over the medium- to long-term or translate into better cardiovascular outcomes or longer kidney transplant survival with function remains unclear. Longer-term, fully reported and published studies comparing belatacept versus tacrolimus are needed to help clinicians decide which patients might benefit most from using belatacept.

Cost utility analysis of immunosuppressive regimens in adult renal transplant recipients in England and Wales

BACKGROUND

End-stage renal disease is the irreversible final stage of chronic kidney disease and is fatal when not managed by either transplantation or dialysis. Transplantation is generally preferred over dialysis. However, to prevent graft rejection or loss, lifelong immunosuppression is required. Tacrolimus is currently the cornerstone of post-transplantation immunosuppression. The study aim was to carry out an economic evaluation of immunosuppression, including more recent agents such as a once-daily prolonged-release formulation of tacrolimus (Advagraf™) and belatacept, relative to a twice-daily immediate-release formulation of tacrolimus (Prograf™).

METHODS

A MODEL WAS CONSTRUCTED COMPRISING SIX STATES: onset of biopsy-confirmed acute rejection, functioning graft with or without a biopsy-confirmed acute rejection, non-functioning graft (dialysis), re-transplantation, and death. Data on clinical effectiveness were derived from a systematic literature review and the model captured the effects of patient adherence to immunosuppressant therapy on graft survival using relative risk of graft survival and published data on adherence in patients using Advagraf and Prograf. In the base case, the time horizon was 25 years and one-way and probabilistic sensitivity analyses were conducted.

RESULTS

The analysis demonstrated that Prograf was cost-effective when compared with cyclosporin and belatacept and was more effective than sirolimus, but would not be considered cost-effective against sirolimus. The modeled improvement in the adherence profile of patients using Advagraf relative to Prograf resulted in both improved clinical outcomes and reduced costs.

CONCLUSION

Prograf was more clinically effective than cyclosporin, belatacept, and sirolimus, supporting its current positioning as the mainstay of immunosuppressive therapy in renal transplant recipients. Based on improved patient adherence with Advagraf, the model projected that Advagraf would be both more effective and less costly than Prograf. Replacing Prograf with Advagraf as the standard of care for post-transplant immunosuppression could likely result in both cost savings and improved clinical outcomes.