Poor Tolerance of Sirolimus in a Steroid Avoidance Regimen for Renal Transplantation

The Effects of Different Administration Regimens of Berberine Hydrochloride on the Pharmacokinetics of Sirolimus in Rats

Sirolimus is a third-generation immunosuppressant with multiple efficacies, including antifungal, antitumor, and immunosuppressive properties. We conducted a pharmacokinetic study to determine the effect of berberine hydrochloride (BBR) on the pharmacokinetics of sirolimus in rats. Thirty-six rats were randomly divided into six groups, and blood samples were collected from the posterior orbital venous plexus at different time points after the last administration to determine the plasma concentration of sirolimus. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for detection, and DAS 2.0 software was employed for pharmacokinetic analysis. A single administration of BBR significantly reduced the pharmacokinetic parameter AUC0-12h of sirolimus. Repeated administration of BBR resulted in an upward trend in Cmax AUC0-12h, AUC0-∞, and CLz all show an upward trend. This study indicates that BBR has a certain impact on the pharmacokinetics of sirolimus in rats. However, further validation of the role of gene polymorphism in pharmacokinetics and clinical efficacy is needed for further research in a wider population.

Mammalian Target of Rapamycin Inhibitors and Wound Healing Complications in Kidney Transplantation: Old Myths and New Realities

Mammalian target of rapamycin inhibitors (mTOR-I) lacks nephrotoxicity, has antineoplastic effects, and reduces viral infections in kidney transplant recipients. Earlier studies reported a significant incidence of wound healing complications and lymphocele. This resulted in the uncomfortable willingness of transplant clinicians to use these agents in the immediate posttransplant period. As evidence and experience evolved over time, much useful information became available about the optimal use of these agents. Understandably, mTOR-I effects wound healing through their antiproliferative properties. However, there are a lot of other immunological and nonimmunological factors which can also contribute to wound healing complications. These risk factors include obesity, uremia, increasing age, diabetes, smoking, alcoholism, and protein-energy malnutrition. Except for age, the rest of all these risk factors are modifiable. At the same time, mycophenolic acid derivatives, steroids, and antithymocyte globulin (ATG) have also been implicated in wound healing complications. A lot has been learnt about the optimal dose of mTOR-I and their trough levels, its combinations with other immunosuppressive medications, and patients' profile, enabling clinicians to use these agents appropriately for maximum benefits. Recent randomized control trials have further increased the confidence of clinicians to use these agents in immediate posttransplant periods.

The evolution of donation after circulatory death renal transplantation: a decade of experience

BACKGROUND

This study compared long-term outcomes of renal transplantation from donors following donation after circulatory death (DCD) with those following donation after brain death (DBD) from one of the largest centres in the UK.

METHOD

Recipients of renal transplants from deceased donors between 2002 and 2014 were identified from a prospectively maintained database. Outcomes were compared between DCD (468) and DBD (905) donors and between standard criteria donors (SCDs) and extended criteria donors (ECDs).

RESULTS

Graft survival (GS) and patient survival (PS) from DCD and DBD donors were comparable up to 10 years (GS: 61 versus 55%, P = 0.780; PS: 78 versus 71%, P = 0.285, respectively). Graft function was comparable after 3 months. GS and function were worse in the ECD groups, with no difference between EC-DBD and EC-DCD. PS in the ECD groups was worse than the SCD groups and PS in the EC-DCD group was worse than in the EC-DBD group. DCD donors were an independent risk factor for delayed graft function. Post-operative complications and EC-DCD donation were independent risk factors for reduced GS and PS.

CONCLUSION

This study supports the use of DCD renal grafts with comparable long-term survival and function to DBD grafts. The use of EC-DCD grafts is justified in selected recipients and provides acceptable function and survival advantages over dialysis.

The 3C Study Collaborative Group, Haynes R, Blackwell L, Staplin N, Herrington WG, Emberson J, Judge PK, Storey BC, Landray MJ, Harden PN, Baigent C, Friend P. Campath, calcineurin inhibitor reduction, and chronic allograft nephropathy (the 3C Study) - results of a randomized controlled clinical trial

Calcineurin inhibitors (CNIs, eg, tacrolimus) reduce short-term kidney transplant failure, but chronic nephrotoxicity may contribute to late transplant loss. Elective conversion to inhibitors of the mammalian target of rapamycin (mTOR, eg, sirolimus) pathway might avoid long-term CNI renal damage and improve outcomes. The 3C Study was a pragmatic randomized controlled trial of sequential randomizations between alemtuzumab and basiliximab induction therapy (at the time of surgery) and between tacrolimus and sirolimus maintenance therapy at 6 months posttransplantation. The primary outcome of this analysis was estimated glomerular filtration rate (eGFR) at 18 months after maintenance therapy randomization; 197 patients were assigned sirolimus-based and 197 to tacrolimus-based therapy. Allocation to sirolimus had no significant effect on eGFR at 18 months: baseline-adjusted mean (SEM) eGFR was 53.7 (0.9) mL/min/1.73 m² in the sirolimus group versus 54.6 (0.9) mL/min/1.73 m² in the tacrolimus group (P = .50). Biopsy-proven acute rejection (29 [14.7%]) vs 6 [3.0%]; P < .001) and serious infections (defined as opportunistic infections or those requiring hospitalization; 95 [48.2%] vs 70 [35.5%]; P = .008) were more common among participants allocated sirolimus. Compared with tacrolimus-based therapy, sirolimus-based maintenance therapy did not improve transplant function at 18 months after conversion and was associated with significant hazards of rejection and infection. ClinicalTrials.gov identifier NCT01120028 and ISRCTN88894088.

Immunosuppressive therapy for kidney transplantation in adults: a systematic review and economic model

BACKGROUND

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

OBJECTIVES

To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation.

METHODS

Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and the American Economic Association's electronic bibliography (via EconLit, EBSCOhost). Included studies were selected according to predefined methods and criteria. A random-effects model was used to analyse clinical effectiveness data (odds ratios for binary data and mean differences for continuous data). Network meta-analyses were undertaken within a Bayesian framework. A new discrete time-state transition economic model (semi-Markov) was developed, with acute rejection, graft function (GRF) and new-onset diabetes mellitus used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Eighty-nine randomised controlled trials (RCTs), of variable quality, were included. For induction therapy, no treatment appeared more effective than another in reducing graft loss or mortality. Compared with placebo/no induction, rATG and BAS appeared more effective in reducing biopsy-proven acute rejection (BPAR) and BAS appeared more effective at improving GRF. For maintenance therapy, no treatment was better for all outcomes and no treatment appeared most effective at reducing graft loss. BEL + MMF appeared more effective than TAC + MMF and SRL + MMF at reducing mortality. MMF + CSA (ciclosporin), TAC + MMF, SRL + TAC, TAC + AZA (azathioprine) and EVL + CSA appeared more effective than CSA + AZA and EVL + MPS at reducing BPAR. SRL + AZA, TAC + AZA, TAC + MMF and BEL + MMF appeared to improve GRF compared with CSA + AZA and MMF + CSA. In the base-case deterministic and probabilistic analyses, BAS, MMF and TAC were predicted to be cost-effective at £20,000 and £30,000 per quality-adjusted life-year (QALY). When comparing all regimens, only BAS + TAC + MMF was cost-effective at £20,000 and £30,000 per QALY.

LIMITATIONS

For included trials, there was substantial methodological heterogeneity, few trials reported follow-up beyond 1 year, and there were insufficient data to perform subgroup analysis. Treatment discontinuation and switching were not modelled.

FUTURE WORK

High-quality, better-reported, longer-term RCTs are needed. Ideally, these would be sufficiently powered for subgroup analysis and include health-related quality of life as an outcome.

CONCLUSION

Only a regimen of BAS induction followed by maintenance with TAC and MMF is likely to be cost-effective at £20,000-30,000 per QALY.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013189.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Steroid avoidance or withdrawal for kidney transplant recipients

BACKGROUND

Steroid-sparing strategies have been attempted in recent decades to avoid morbidity from long-term steroid intake among kidney transplant recipients. Previous systematic reviews of steroid withdrawal after kidney transplantation have shown a significant increase in acute rejection. There are various protocols to withdraw steroids after kidney transplantation and their possible benefits or harms are subject to systematic review. This is an update of a review first published in 2009.

OBJECTIVES

To evaluate the benefits and harms of steroid withdrawal or avoidance for kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 15 February 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

All randomised and quasi-randomised controlled trials (RCTs) in which steroids were avoided or withdrawn at any time point after kidney transplantation were included.

DATA COLLECTION AND ANALYSIS

Assessment of risk of bias and data extraction was performed by two authors independently and disagreement resolved by discussion. Statistical analyses were performed using the random-effects model and dichotomous outcomes were reported as relative risk (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals.

MAIN RESULTS

We included 48 studies (224 reports) that involved 7803 randomised participants. Of these, three studies were conducted in children (346 participants). The 2009 review included 30 studies (94 reports, 5949 participants). Risk of bias was assessed as low for sequence generation in 19 studies and allocation concealment in 14 studies. Incomplete outcome data were adequately addressed in 22 studies and 37 were free of selective reporting.The 48 included studies evaluated three different comparisons: steroid avoidance or withdrawal compared with steroid maintenance, and steroid avoidance compared with steroid withdrawal. For the adult studies there was no significant difference in patient mortality either in studies comparing steroid withdrawal versus steroid maintenance (10 studies, 1913 participants, death at one year post transplantation: RR 0.68, 95% CI 0.36 to 1.30) or in studies comparing steroid avoidance versus steroid maintenance (10 studies, 1462 participants, death at one year after transplantation: RR 0.96, 95% CI 0.52 to 1.80). Similarly no significant difference in graft loss was found comparing steroid withdrawal versus steroid maintenance (8 studies, 1817 participants, graft loss excluding death with functioning graft at one year after transplantation: RR 1.17, 95% CI 0.72 to 1.92) and comparing steroid avoidance versus steroid maintenance (7 studies, 1211 participants, graft loss excluding death with functioning graft at one year after transplantation: RR 1.09, 95% CI 0.64 to 1.86). The risk of acute rejection significantly increased in patients treated with steroids for less than 14 days after transplantation (7 studies, 835 participants: RR 1.58, 95% CI 1.08 to 2.30) and in patients who were withdrawn from steroids at a later time point after transplantation (10 studies, 1913 participants, RR 1.77, 95% CI 1.20 to 2.61). There was no evidence to suggest a difference in harmful events, such as infection and malignancy, in adult kidney transplant recipients. The effect of steroid withdrawal in children is unclear.

AUTHORS' CONCLUSIONS

This updated review increases the evidence that steroid avoidance and withdrawal after kidney transplantation significantly increase the risk of acute rejection. There was no evidence to suggest a difference in patient mortality or graft loss up to five year after transplantation, but long-term consequences of steroid avoidance and withdrawal remain unclear until today, because prospective long-term studies have not been conducted.

Molecular pathways and therapies in autosomal-dominant polycystic kidney disease

Autosomal-dominant polycystic kidney disease (ADPKD) is the most prevalent inherited renal disease, characterized by multiple cysts that can eventually lead to kidney failure. Studies investigating the role of primary cilia and polycystins have significantly advanced our understanding of the pathogenesis of PKD. This review will present clinical and basic aspects of ADPKD, review current concepts of PKD pathogenesis, evaluate potential therapeutic targets, and highlight challenges for future clinical studies.

Novel Sirolimus–Coated Balloon Catheter

Background—

Limus-eluting stents are dominating coronary interventions, although paclitaxel is the only drug on balloon catheters with proven inhibition of restenosis. Neointimal inhibition by limus-coated balloons has been shown in few animal studies, but data from randomized clinical trials are not available. The aim of the present preclinical studies was to achieve high and persistent sirolimus levels in the vessel wall after administration by a coated balloon.

Methods and Results—

Different coating formulations and doses were studied in the porcine coronary model to investigate sirolimus tissue levels at different time points as well as efficacy at 1 month using quantitative coronary angiography and histomorphometry. Loss of the selected coating in the valve, guiding catheter, and blood was low (2±14% of dose). Acute drug transfer to the vessel wall was 14.4±4.6% with the crystalline coating, whereas the amorphous coatings were less effective in this respect. Persistence of sirolimus in the vessel wall until 1 month was 40% to 50% of the transferred drug. At 1-month follow-up, a modest but significant reduction of neointimal growth was demonstrated in a dose range from 4 μg/mm 2 to 2×7 μg/mm 2 , for example, maximum neointimal thickness of 0.38±0.13 versus 0.65±0.21 mm in the uncoated control group.

Conclusions—

Various sirolimus-coated balloons effectively reduce neointimal proliferation in the porcine coronary model but differ considerably in retention time in the vessel wall. It has to be determined if such a formulation with persistent high vessel concentration will result in a relevant clinical effect.

Ureteric reconstruction for the management of transplant ureteric stricture: a decade of experience from a single centre

This study was conducted to review the outcomes of patients who had undergone surgical repair of a ureteric stricture following renal transplantation. All patients who developed a ureteric stricture and underwent ureteric reconstruction following renal transplantation, between December 2003 and November 2013, were reviewed. One thousand five hundred and sixty renal transplants were performed during the study period. Forty patients required surgical repair of a ureteric stricture (2.5%, 25 male, median age 48 [14-78]). The median time to stricture was 3 [1-149] months. 19 patients were reconstructed by reimplantation to the bladder, 18 utilized a Boari flap, two were a pre-existing ileal conduit and one was an anastomosis to a native ureter. In one patient, reconstruction was impossible and consequently an extra-anatomic stent was used. Two patients required re-operation for restricture and kinking. Median serum creatinine at 12 months following surgery was 148 [84-508] μmol/l. There was no 90-day mortality. Eleven grafts were lost at the time of this study, a median time of 11 [1-103] months after reconstruction. The incidence of ureteric stricture following renal transplant is low. Surgical reconstruction of the transplant ureter is the optimal treatment and is successful in the majority of patients.

A systematic review of conversion from calcineurin inhibitor to mammalian target of rapamycin inhibitors for maintenance immunosuppression in kidney transplant recipients

This was a systematic review of randomized controlled trials comparing delayed conversion of mammalian target of rapamycin inhibitors (mTORi) for calcineurin inhibitors (CNIs) versus CNI continuation in kidney transplantation. Databases (2000-2012) and conference abstracts (2009-2012) were searched giving a total of 29 trials. Outcomes analyzed included GFR, graft loss, rejection and adverse events and were expressed as weighted mean differences (WMDs) or as risk ratios (RRs). Patients converted to mTORi up to 1 year posttransplant in intention-to-treat analysis had higher GFR compared with those remaining on CNI (WMD 0.28 mL/min/1.73 m(2) , 95% confidence interval [CI] 0.21-0.36; I(2)  = 68%, p < 0.001). Stratifying trials by time posttransplant or type of mTORi did not change the overall heterogeneity. For on-treatment population, mTORi was associated with higher GFR (14.21 mL/min/1.73 m(2) , 10.34-18.08; I(2)  = 0%, p = 0.970) 2-5 years posttransplant. The risk of rejection at 1 year was higher in mTORi trials (RR 1.72, 1.34-2.22; I(2)  = 12%, p = 0.330). Discontinuation secondary to adverse events was more common in patients on mTORi, whereas the incidence of skin cancers and cytomegalovirus infection was lower in patients on mTORi. Conversion from CNI to mTORi is associated with short-term improvements in GFR in a number of studies but longer-term follow-up data of graft and patient survival are required.

Alemtuzumab and sirolimus in renal transplantation: six-year results of a single-arm prospective pilot study

mTOR inhibitors avoid calcineurin nephrotoxicity, but sirolimus de novo is associated with unacceptable side effects and higher rejection rates. We have investigated a modified strategy: alemtuzumab induction with tacrolimus and mycophenolate maintenance, switching from tacrolimus to sirolimus at 6 months and stopping mycophenolate at 12 months. Here, we report the 6-year follow-up of 30 patients prospectively recruited to this single-arm pilot study and compare outcomes to a matched contemporaneous control group of 30 patients who received standard induction and calcineurin-inhibitor-based immunosuppression.Six-year patient and graft survival were 83% and 80%(alemtuzumab) versus 77% and 70% (control). Rejection rates in the first 6 months were similar in alemtuzumab (6.6%) and control groups (10%). A higher than expected incidence of rejection in the alemtuzumab group following cessation of mycophenolate at 1 year (17%) was mitigated in later patients by retaining low dose mycophenolate. Mean eGFR was higher in the alemtuzumab group at all time points but not significantly (p¼0.16). Tacrolimus levels in the first 6 months were significantly higher in the contemporaneous control group (p<0.001). Alemtuzumab induction with initial treatment with tacrolimus enables conversion to sirolimus without the side effects and incidence of acute rejection seen in earlier protocols.

High incidence of rejection episodes and poor tolerance of sirolimus in a protocol with early steroid withdrawal and calcineurin inhibitor-free maintenance therapy in renal transplantation: experiences of a randomized prospective single-center study

Immunosuppressive maintenance therapy after kidney transplantation leads to various undesired side effects such as calcineurin inhibitor (CNI)-associated nephrotoxicity or elevated cardiovascular risk due to posttransplantation diabetes and hypertension. These effects show negative impacts on long-term allograft function as well as patient morbidity and mortality. Therefore, we used an immunosuppressive regimen with early corticosteroid withdrawal (ESW), maintenance therapy containing tacrolimus, sirolimus (SRL), and mycophenolate sodium for 3 months followed by a prospective randomized trial comparing a CNI free versus a low-dose CNI therapy. The primary endpoint was 6-month graft function. Among 75 patients, ESW was performed after 4 days in 65 patients. Over the following 3 months before randomization to CNI-free maintenance therapy, we experienced a high number (25%) of SRL discontinuations due to adverse events, including leukopenia, anemia, arthritis, and pneumonitis. In addition there were significantly more allograft rejection episodes in the CNI-free group (P = .017) during the study period leading to a switch from SRL to a CNI. Despite the higher rate of rejection episodes in the CNI-free groups, glomerular filtration rates (GFR) at 6 months were comparable between the study groups (P = .25). After 1 year only 9.2% (6/65) of all patients treated with SRL remained on this drug. Conclusion, there was an unacceptably high rate of SRL intolerance using an ESW and CNI-free immunosuppressive regimen combined with a significantly higher rate of rejection episodes.

Wound healing complications and the use of mammalian target of rapamycin inhibitors in kidney transplantation: a critical review of the literature

Surgical complications, including events such as lymphocele and urological complications that affect wound healing, are reported with an incidence of 15% to 32% after kidney transplantation. The experience of the surgeon and comorbidities play an important role in determining the risk of such complications occurring. Since the introduction of the inosine 5'-monophosphate dehydrogenase inhibitors (mycophenolate mofetil) to the immunosuppressive armamentarium, replacing the antimetabolite prodrug azathioprine, reports have associated certain forms of wound healing complications (wound dehiscence, impaired healing, lymphocele, and incisional hernia) with the use of these agents. When mammalian target of rapamycin (mTOR) inhibitors (sirolimus, everolimus) became available, these findings were observed increasingly, particularly in direct comparisons with inosine 5'-monophosphate dehydrogenase inhibitors. The purpose of this article was to review the reported incidence of wound healing complications from randomized clinical trials that investigated the use of sirolimus- and everolimus-based treatment regimens in de novo kidney transplantation and the information available from the U.S. Food and Drug Administration database. The clinical trials included were primarily identified using biomedical literature database searches, with additional studies added at the authors' discretion. This review summarizes these studies to consider whether modern mTOR inhibitor-based immunosuppressive regimens exert and affect wound healing after kidney transplantation.

Defining the role of sirolimus in the management of graft-versus-host disease: from prophylaxis to treatment

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Measures developed that have significantly reduced GVHD were also frequently associated with an increased risk of relapse. GVHD and graft-versus-tumor (GVT) effects are tightly linked, and balance between both reactions is difficult to achieve. To have an impact on the outcome and quality of life after HSCT, improvements in current strategies to prevent and treat GVHD while preserving the GVT effect are clearly needed. Sirolimus (rapamycin) is a lipophilic macrocytic lactone with immunosuppressive, antitumor, and antiviral properties. Because of its multiple modes of activities, it is being increasingly used in the management of GVHD. This review aims to summarize its mechanisms of action and potential advantages over other immunosuppressors and to analyze the most relevant studies investigating its role in both prevention and treatment of GVHD.

Five-year results of a randomized trial comparing de novo sirolimus and cyclosporine in renal transplantation: the SPIESSER study

Calcineurin inhibitors improve acute rejection rates and short-term graft survival in renal transplantation, but their continuous use may be deleterious. We evaluated the 5-year outcomes of sirolimus (SRL) versus cyclosporine (CsA) immunosuppressive treatment. This observational study was an extension of the SPIESSER study where deceased donor kidney transplant recipients were randomized before transplantation to a SRL- or CsA-based regimen and followed up 1 year. Data from 131 (63 SRL, 68 CsA) out of 133 patients living with a functional graft at 1 year were collected retrospectively at 5 years posttransplant. Seventy percent of CsA patients versus 54% of SRL patients were still on the allocated treatment at 5 years (p = 0.091), most discontinuations in each group being due to safety issues. In intent-to-treat, mean MDRD eGFR was higher with SRL: 54.2 versus 45.3 mL/min with CsA (p = 0.019); SRL advantage was greater in on-treatment analyses. There were no differences for patient survival (p = 0.873), graft survival (p = 0.121) and acute rejection (p = 0.284). Adverse events were more frequent with SRL (80% vs. 60%, p = 0.015). Results confirmed the high SRL discontinuation rate due to adverse events. Nevertheless, a benefit was evidenced on renal function in patients (more than 50%) still on treatment at 5 years.

Different patterns of BK and JC polyomavirus reactivation following renal transplantation

AIM

Reactivation of latent BK polyomavirus (BKV) infection is relatively common following renal transplantation and BKV-associated nephropathy has emerged as a significant complication. JC polyomavirus (JCV) reactivation is less well studied. The aim of the study was to determine reactivation patterns for these polyomaviruses in renal transplant recipients using an in-house quantitative real-time multiplex PCR assay and IgG serological assays using recombinant BK and JC virus-like particles.

METHODS

Retrospective analysis of urine and plasma samples collected from 30 renal transplant patients from February 2004 to May 2005 at Leeds Teaching Hospitals NHS Trust. Samples were collected at 5 days and thereafter at 1, 3, 6 and 12 months post-transplantation.

RESULTS

Eight patients (26.7%) were positive for BK viruria; three of these patients submitted plasma samples and two had BK viraemia. Five patients (16.7%) were positive for JC viruria. A corresponding rise in BKV and JCV antibody titres was seen in association with high levels of viruria.

CONCLUSIONS

Different patterns of reactivation were observed: BK viruria was detected after 3-6 months, and JC viruria was observed as early as 5 days post-transplantation. One patient had biopsy-proven BKV nephropathy. No dual infections were seen. In order to ensure better graft survival, early diagnosis of these polyomaviruses is desirable.

Use of kidney function end points in kidney transplant trials: a systematic review

BACKGROUND

Clinical trials in kidney transplantation are beginning to include markers of kidney function as end points now that traditional outcomes, such as acute rejection, become increasingly rare events. The frequency and type of kidney function end points used are unknown.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Randomized controlled trials in adult kidney transplant recipients reported in 5 major general medical journals and 5 major subspecialty journals in nephrology and transplantation between January 2003 and November 2008.

SELECTION CRITERIA

Inclusion of at least one kidney function end point at least 1 month posttransplant.

RESULTS

133 (79%) of 169 randomized trials identified used a kidney function end point. Of these, 37 (28%) used one or more measures of kidney function as the primary end point, and 81 (61%), as a secondary end point. For the primary end point, 21 (57%) trials used a creatinine-based estimated glomerular filtration rate (eGFR), 18 (49%) used serum creatinine level, and 7 (19%) used measured GFR. Overall, eGFR was an end point in 81 (61%) trials, and measured GFR, in 12 (9%) trials.

LIMITATIONS

This review is limited by the poor quality of the included trials, with many not defining either primary or secondary end points.

CONCLUSIONS

Measures of kidney function are used commonly as surrogate end points in kidney transplant trials, with eGFR becoming more frequently used over time. Further data are needed to properly validate these surrogate end points and fully understand their limitations when designing and interpreting randomized trials.

Topics in transplantation medicine for general nephrologists

Before transplantation, the general nephrologist is the primary resource for potential kidney transplantation recipients. After transplantation, the general nephrologist is increasingly managing transplant medications and complications. We provide evidence-based management strategies for common clinical issues. Linking our approach with the data allows the clinician to explore each subject in greater depth to tailor care to individual patients.

Renal and liver tumors in Tsc2(+/-) mice, a model of tuberous sclerosis complex, do not respond to treatment with atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor

Inactivating mutations of the tumor suppressor gene TSC2 are associated with tumorigenesis in tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis. Statins, as 3-hydroxy-3-methylglutaryl CoA reductase inhibitors, have the potential to limit the growth of these tumors by limiting the isoprenylation of activated GTPases in Tsc2-null cells. We tested atorvastatin as a therapy for (a) ethylnitrosourea (ENU)-enhanced renal cystadenoma and (b) spontaneous liver hemangioma in 129Sv/Jae Tsc2(+/-) mice. ENU-treated Tsc2(+/-) mice were given atorvastatin chow (0.1%, w/w) for 1 or 3 months before sacrifice at 6 months; 129Sv/Jae Tsc2(+/-) mice were given atorvastatin chow (0.1%, w/w) for 6 months before sacrifice at 12 months. All treatment groups were compared with mice of identical genotype and strain background that were fed control chow. Pathologic analyses revealed a predominance of renal cystadenoma in ENU-treated and liver hemangioma in non-ENU-treated 129Sv/Jae Tsc2(+/-) mice. In both cohorts, serum cholesterol levels and levels of phosphorylated S6 and GTP-RhoA in healthy tissue were significantly (>50%) reduced in atorvastatin-treated mice as compared with controls. Following atorvastatin treatment, no significant reduction in tumor size, morphology, or phosphorylated S6 levels was observed for either ENU-associated renal cystadenoma or spontaneous liver hemangioma as compared with the untreated groups. In conclusion, although the marked reduction in cholesterol levels indicates that atorvastatin was effective as an 3-hydroxy-3-methylglutaryl CoA reductase inhibitor, it did not inhibit the growth of tumors that develop in these Tsc2(+/-) models, suggesting that it is unlikely to have benefit as a single-agent therapy for TSC-associated tumors.