P6277The impact of exercise training in combination with statin use on skeletal muscle mitochondrial oxidative phosphorylation and metabolomics in obese rats

Background

Exercise training (ET) and statin treatment both alter skeletal muscle function.

Purpose

We investigated the effects of a combined exercise and statin use on skeletal muscle mitochondrial oxidative phosphorylation (OxPhos) and metabolic alterations in obese rats.

Methods

Eight-week-old male Wistar rats were used. A total of 14 animals received standard chow, while 46 rats were fed a high-fat diet (HFD) for 20 weeks. After 8 weeks, the rats were randomized into 6 groups: sedentary (n=8), ET (n=6), sedentary with HFD (n=11), ET with HFD (n=11), statin with HFD (n=13) and ET with HFD and statins (n=11). Simvastatin (10mg/d/kg) was added to the drinking water. ET was performed for 12 weeks, 5 days/week for 1 h/day at 18 m/min in a motorized running wheel. OxPhos was assessed by complex-specific antibodies and targeted metabolomics using the Biocrates p180 kit. All experiments were done on frozen samples of the M. gastrocnemicus. An ANOVA with fixed effects for diet, exercise, statin treatment and statin-exercise interaction was used to identify significantly different metabolites.

Results

Statin use was associated with significantly lower cholesterol levels, but did not affect exercise duration and intensity compared to none-use. In sedentary animals, HFD increased OxPhos complex II (succinate dehydrogenase), complex IV (cytochrome-c-oxidase) and V (ATP synthase) while statin treatment diminished this increase in all complexes. HFD increased complex IV independent of statin treatment but had no effect on complex II and V in ET rats. Complex IV was increased due to ET only in HFD fed rats compared to rats on normal chow but decreased in contrast to sedentary animals on a HFD. With regards to metabolomics, we found 57 metabolites which were influenced by HFD while no metabolites were identified with a significant effect for ET. A significant statin-exercise interaction was found for three lysophosphatidylcholines (lysoPC a C26.0, lysoPC a C26.1, lysoPC a C24.0), one phosphatidylcholine (PC aa C42.6) and one sphingomyelin (SM C16.1). HFD decreased the concentration of all mentioned metabolites compared to standard chow fed animals. Likewise, ET increased the concentration of metabolites compared to sedentary animals on HFD. Statin treatment led to an increase, while statin in combination with ET did not rescue this effect.

Conclusion

HFD induced severely impaired skeletal muscle OxPhos independent of ET and statin treatment. Our findings suggest a limiting rate of NADH production in the tricarboxylic acid cycle as a potential mechanism. However, ET prevented the increase in cytochrome-c-oxidation while statins blocked the HFD induced increase in ATP synthase. Our metabolomics results imply that future research should consider the lipotoxic effects of a HFD when assessing skeletal muscle alterations due to ET or statins. Of particular interest could be the 5 metabolites that have been shown to be impacted by a statin-exercise interaction.

Impact of Pre-existing Comorbidities on Long-term Outcomes in Kidney Transplant Recipients

BACKGROUND

Outcomes of patients with end-stage renal disease are mainly affected by their comorbidities. Detailed data evaluating the impact of pre-transplant comorbidities on long-term outcome after kidney transplantation are largely missing.

METHODS

In a long-term retrospective analysis, we investigated 839 deceased donor kidney transplant recipients (KTRs) who received transplants between 1999 and 2014. The prevalence and impact of the most relevant comorbidities were studied in detail.

RESULTS

At the time of transplantation, 25% of KTRs had coronary artery disease (CAD), 16% had diabetes mellitus (DM), 11% had peripheral arterial disease (PAD), 8% had chronic heart failure (CHF), and 7% had cerebrovascular disease (CVD). KTRs with pre-existing CAD, DM, PAD, and CHF showed a significantly inferior patient survival. Multivariate analysis adjusting for all relevant factors and comorbidities confirmed CAD as most hazardous independent risk factor for premature death (hazard ratio [HR] 1.70; P = .002). A multivariate analysis revealed CHF and PAD as independent risk factors for death censored graft loss (HR 2.20; P = .003 and HR 1.80; P = .013). Diabetes was independently and significantly associated with T-cell- (HR 1.46; P = .020) and antibody-mediated rejections (HR 2.27; P = .030).

CONCLUSIONS

Detailed quantification of the impact of pre-transplant comorbidities may facilitate the evaluation of transplant candidates, guide post-transplant follow-up, and may help to further refine prediction algorithms and allocation systems.

Effect of everolimus on skin lesions in patients treated for subependymal giant cell astrocytoma and renal angiomyolipoma: final 4-year results from the randomized EXIST-1 and EXIST-2 studies

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder associated with tumour growth in various organs, including the brain, kidneys, heart and skin. Cutaneous lesions are prevalent manifestations of TSC, occurring in up to 90% of patients. Oral mammalian target of rapamycin inhibitors, such as everolimus, is believed to be effective for treatment of TSC-associated lesions because they act on the underlying disease pathophysiology.

OBJECTIVE

We evaluated the long-term effect of oral everolimus on TSC-associated skin lesions as a secondary objective in the phase III studies EXIST-1 (NCT00789828) and EXIST-2 (NCT00790400) after approximately 4 years of treatment.

MATERIALS AND METHODS

Everolimus was dosed 4.5 mg/m² /day (titrated to trough 5-15 ng/mL) in patients with TSC-associated subependymal giant cell astrocytoma in EXIST-1, and 10 mg/day initially in adult patients with TSC- or sporadic lymphangioleiomyomatosis-associated renal angiomyolipoma in EXIST-2. Following positive results from the core phase, remaining patients were offered open-label everolimus in an extension. Skin lesion response rate was the proportion of patients achieving complete or partial clinical response.

RESULTS

A total of 105 patients in EXIST-1 and 107 in EXIST-2 received everolimus and had ≥1 skin lesion at baseline. Skin lesion response rate (95% confidence interval) was 58.1% (48.1-67.7%) in EXIST-1 and 68.2% (58.5-76.9%) in EXIST-2; most were partial responses. At week 192 (EXIST-1: n = 55; EXIST-2: n = 56), 69% and 66% had a response. Most common drug-related adverse event was stomatitis (41-45%).

CONCLUSION

Oral everolimus improved TSC-related skin lesions, with responses sustained over 4 years of treatment in EXIST-1 and EXIST-2.

Incidence of Infectious Disease and Malignancies After Rituximab Therapy in Kidney Transplant Recipients: Results From a Cohort in Germany

BACKGROUND

Rituximab is frequently used in solid organ transplantation off-label, especially in patients with renal allografts. Few data are available on the safety aspects of solid organ transplant recipients receiving rituximab. There is a knowledge gap on long-term follow-up data, in particular on infectious complications.

PATIENTS AND METHODS

A retrospective observational registry study (German Registry on Autoimmune Diseases) comprising a total of 681 patients was conducted. The data of 63 adult kidney transplant recipients who received rituximab between 2006 and 2013 were used in this analysis.

RESULTS

Median follow-up was 42 (1-109) months. At least 1 severe infection occurred in 57% of patients. The median time between the first rituximab infusion and the first infection was 4 (1-48) months. Of the overall 88 infections, 74 were severe bacterial infections, 5 were severe viral infections, 3 were severe fungal infections, 2 were combined severe bacterial and fungal infections, and 4 were combined severe viral, fungal and bacterial infections. Seven patients died during the observational period, 2 of them due to infectious complications. In the observational period, 1 case of squamous cell carcinoma but no other malignancies were observed.

CONCLUSION

Consistent with previous data, a high incidence of infections was observed after rituximab treatment in kidney transplant recipients. Most infections occurred within 6 months after rituximab initiation. With more than 3 years of follow-up, we were able to document a low incidence of secondary malignancies after rituximab with only 1 case in our cohort.

Long-Term Outcomes of Kidney Transplant Recipients With Primary Idiopathic Focal Segmental Glomerulosclerosis

BACKGROUND

Few data exist on recurrence rates, treatment response, and long-term outcomes in kidney transplant recipients (KTR) with primary focal segmental glomerulosclerosis (FSGS).

METHODS

This retrospective, observational study included 1218 consecutive KTR during 2002 to 2016. All patients with primary idiopathic FSGS were identified through application of strict diagnostic criteria. Outcomes were followed over an average of 70.4 months.

RESULTS

We identified 48 KTR (3.9%) with primary FSGS. Seven-year death-censored graft survival rate was 81% (primary FSGS) versus 85% (control) (P = .297). Eighteen KTR had FSGS recurrence (predicted incidence, 50% after 7 years). Seven-year death-censored graft survival rate in KTR with FSGS recurrence was significantly worse than in FSGS KTR without recurrence (63% versus 96%, P = .010). In the case of FSGS recurrence, a multi-modal treatment approach was applied, including plasma exchange (PE) (100% of patients), intravenous cyclosporine (50%), rituximab (61%), and the "Multiple Target Treatment" (39%). The median number of PE sessions was 27. Proteinuria decreased significantly and persistently during the course of treatment. Complete remission of FSGS was observed in 7 patients (39%); another 7 patients (39%) had partial remission (PE dependence was observed in 4 patients [22%]). Four patients (22%) with FSGS recurrence had early graft loss (<6 months after transplant) despite all treatment efforts.

CONCLUSIONS

In KTR with primary FSGS, a high proportion of recurrence occurred, and recurrence was associated with significantly worse death-censored graft survival rates. However, a multi-modal treatment approach led to improvement of proteinuria and full or partial remission in most patients. Importantly, overall death-censored graft survival rate in KTR with primary FSGS was comparable with that in the control group.

Immunologic Long-term Outcomes of Living-Related Kidney Transplantations Depending on the Donor-Recipient Relationship

BACKGROUND

The aim of this study is to analyze the long-term immunologic outcomes of living-related kidney transplantations depending on the donor-recipient relationship.

METHODS

This retrospective single-center study included adult kidney transplant recipients (KTR) transplanted between 2000 and 2014. Among 1117 KTRs, 178 patients (15.9%) received living-related donations. Those patients were further categorized according to the donor-recipient relationship: 65 transplantations between siblings, 39 father-to-child (F-t-C) and 74 mother-to-child (M-t-C) donations. Allograft biopsies were performed for clinically suspected rejections. Data analysis included patient and graft survival, biopsy proven rejections (T-cell mediated [TCMR] or antibody mediated) and development of de novo donor-specific antibody. Outcome data were assessed over a period of a maximum 14 years.

RESULTS

There was no significant difference between the groups (F-t-C, M-t-C, and siblings) with regard to HLA-mismatches, prior kidney transplantations, time on dialysis, and cold ischemia time. Among KTRs with related donors, the type of relationship had no significant influence on graft survival. F-t-C and M-t-C pairs showed comparable incidences of TCMR at 7 years post-transplantation, both significantly exceeding the rate in sibling-to-sibling pairs (26.2% and 26.8% vs 10%, respectively; P = .043). A multivariate Cox regression analysis adjusted for recipient age, donor age, and HLA (A, B, DR)-mismatches identified both M-t-C- and F-t-C-donations as important independent risk factors for TCMR (hazard ratio: 8.13; P < .001 and hazard ratio: 8.09; P = .001, respectively). There was no significant difference between the groups concerning the incidence of antibody-mediated rejection and de novo donor-specific antibody.

CONCLUSION

Our results indicate that parent-to-child kidney donation is an independent risk factor for TCMR.

Donor-Recipient Matching Based on Predicted Indirectly Recognizable HLA Epitopes Independently Predicts the Incidence of De Novo Donor-Specific HLA Antibodies Following Renal Transplantation

De novo donor-specific HLA antibodies (dnDSA) are recognized as a risk factor for premature allograft failure. Determinants of DSA specificity are generated via the indirect allorecognition pathway. Here, we present supportive data for the relevance of predicted indirectly recognizable HLA epitopes (PIRCHE) to predict dnDSA following kidney transplantation. A total of 2787 consecutive kidney transplants performed between 1995 and 2015 without preformed DSA have been analyzed. De novo DSA were detected by single antigen bead assay. HLA epitope mismatches were determined by the HLAMatchmaker and PIRCHE approach and correlated in uni- and multivariate analyses with 10-year allograft survival and incidence of dnDSA. The PIRCHE-II score moderately predicted allograft survival. However, the predictive value of elevated PIRCHE-II scores >9 for the incidence of dnDSA was statistically significant (p < 0.001). In a multivariate Cox regression analysis adjusted for antigen mismatch and HLAMatchmaker epitopes, the PIRCHE-II score could be identified as an independent risk factor for dnDSA. The PIRCHE-II score independently from the antigen mismatch and HLAMatchmaker epitopes could be revealed as being a strong predictor for dnDSA. PIRCHE may help to identify acceptable mismatches with decreased risk of dnDSA and thus improve long-term renal allograft survival.

Treatment of renal angiomyolipoma in tuberous sclerosis complex (TSC) patients

In adult tuberous sclerosis complex (TSC) patients, renal complications are the leading cause of death. Beginning in childhood, up to 80 % of patients develop renal angiomyolipoma characterized by a size-dependent risk of life-threatening bleeding. After discovery of the two causative genes, TSC1 and TSC2, and the role of mammalian target of rapamycin (mTOR) regulation in the pathogenesis of TSC, an increasing number of clinical studies evaluating mTOR inhibition in TSC patients have shown impressive results in many organ manifestations, such as brain, lung, and kidney. For renal angiomyolipoma, mTOR inhibitor treatment fundamentally changed the approach from preventive embolization or even partial nephrectomy to everolimus treatment in order to preserve kidney function.

Successful Recovery of Acute Renal Transplant Failure in Recurrent Hepatitis C Virus-Associated Membranoproliferative Glomerulonephritis

Recurrence of hepatitis C virus (HCV)-associated membranoproliferative glomerulonephritis (MPGN) in the kidney transplant may lead to continuous graft deterioration and the need for further renal replacement therapy. The novel direct-acting antiviral agents (DAAs) allow a highly effective and interferon-free treatment option for chronic HCV-infected patients. Data on the therapeutic safety and efficacy in HCV-infected renal transplant patients are sparse, especially for patients with severe renal impairment. We report the case of a 63-year-old female HCV-positive renal transplant patient with biopsy-proven recurrence of MPGN in the renal graft 3 years after transplant. Because of rapid loss of transplant function and consecutive need for hemodialysis, we initiated a combined anti-HCV-directed therapy regimen consisting of daclatasvir and simeprevir over 12 weeks. Viral clearance of HCV was obtained as early as 2 weeks after start of treatment. No adverse therapy-associated side effects were observed, and immunosuppressive dosing remained unchanged. Importantly, graft function fully recovered and hemodialysis was stopped 2 mo after the end of daclatasvir/simeprevir treatment. We report the first case of successful recovery of dialysis-dependent renal transplant failure after treatment of recurrent HCV-associated MPGN in a kidney transplant recipient by curing the underlying HCV infection with a combination of novel DAAs.

Biomarkers in acute kidney injury - pathophysiological basis and clinical performance

Various biomarkers of acute kidney injury (AKI) have been discovered and characterized in the recent past. These molecules can be detected in urine or blood and signify structural damage to the kidney. Clinically, they are proposed as adjunct diagnostics to serum creatinine and urinary output to improve the early detection, differential diagnosis and prognostic assessment of AKI. The most obvious requirements for a biomarker include its reflection of the underlying pathophysiology of the disease. Hence, a biomarker of AKI should derive from the injured kidney and reflect a molecular process intimately connected with tissue injury. Here, we provide an overview of the basic pathophysiology, the cellular sources and the clinical performance of the most important currently proposed biomarkers of AKI: neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver-type fatty acid-binding protein (L-FABP), interleukin-18 (IL-18), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor of metalloproteinase 2 (TIMP-2) and calprotectin (S100A8/9). We also acknowledge each biomarker's advantages and disadvantages as well as important knowledge gaps and perspectives for future studies.

[Immunosuppression and its use in kidney transplantation]

BACKGROUND

Current immunosuppressive protocols effectively prevent acute rejection of renal allografts. Extensive drug toxicity and the deleterious effects of long-term immunosuppression are associated with significant morbidity and mortality.

OBJECTIVES

The purpose of this article is to provide an overview over modern immunosuppressants and their unwanted side effects and to discuss strategies for improved long-term transplant survival.

METHODS

Review of the current topic-related literature and discussion of our own experience.

RESULTS

The use of antibody induction together with an initial combination therapy of calcineurin inhibitors, mycophenolate and steroids is recommended and results in excellent early outcomes. Detrimental effects include an increased incidence of infections, malignomas, and cardiovascular diseases. Long-term transplant survival is impaired by extensive drug toxicity and the frequent development of donor specific antibodies. Reduction of overall cumulative exposure to immunosuppressants or the reduction of specific toxic drugs such as calcineurin inhibitors and steroids may improve long-term results. Alternative immunosuppressants like mTOR inhibitors and belatacept appear to be effective and safe but their long-term effects on patient and allograft survival needs to be established in clinical trials.

CONCLUSIONS

Current immunosuppressants provide effective protection from renal allograft rejection. However, their use is complicated by serious side effects. In the future, development of novel immunosuppressants and optimization of minimization strategies may help to improve long-term success after kidney transplantation.

Living Donor Transplantation: Long-Term Evolution Related to Age Matching

The lack of donors is favoring living kidney donor (LKD) transplantation worldwide, quite often beyond the classic age-matching rules. We analysed renal function (RF) at 1 and 5 years in all donor and recipients as well as death-censored graft and patient survival. LKD recipients were divided into 4 subgroups: young recipients-young donors (YR-YD; N = 355), elderly recipients-young donors (ER-YD; N = 13), young recipients-elderly donors (YR-ED; N = 67), and elderly recipients-elderly donors (ER-ED; N = 38). "Elderly" was defined as ≥60 years. RF was better in those who received a young allograft (YR-YD/ER-YD) at any time (P < .001). There was a trend toward higher proteinuria among the recipients of an old allograft (YR-ED/ER-ED) at any time (P = not significant [NS]). However, our population showed low levels of proteinuria and this was not a risk factor for graft failure. Logistic regression model showed that creatinine level at 1 year is a good predictor of graft losses. Graft survival was worse in the allografts from elderly donors (P < .001). Analysing the young recipients, renal survival was inferior in those who received an old kidney (YR-ED; P < .00005) as well as mortality rates at 14 years (P = .03). The RF of young (N = 295) and elderly donors (N = 98) was optimal with no progression to ESRD or deaths registered during follow-up. In conclusion, young recipients of elderly kidneys pay the price of a worse RF, allograft prognosis, and patient prognosis. The pair YR-ED is a doable option, but we recommend age matching when it is possible.

Evaluation of the effect of tofacitinib exposure on outcomes in kidney transplant patients

Tofacitinib fixed-dose regimens attained better kidney function and comparable efficacy to cyclosporine (CsA) in kidney transplant patients, albeit with increased risks of certain adverse events. This post-hoc analysis evaluated whether a patient subgroup with an acceptable risk-benefit profile could be identified. Tofacitinib exposure was a statistically significant predictor of serious infection rate. One-hundred and eighty six kidney transplant patients were re-categorized to above-median (AME) or below-median (BME) exposure groups. The 6-month biopsy-proven acute rejection rates in AME, BME and CsA groups were 7.8%, 15.7% and 17.7%, respectively. Measured glomerular filtration rate was higher in AME and BME groups versus CsA (61.2 and 67.9 vs. 53.9 mL/min) at Month 12. Fewer patients developed interstitial fibrosis and tubular atrophy (IF/TA) at Month 12 in AME (20.5%) and BME (27.8%) groups versus CsA (48.3%). Serious infections occurred more frequently in the AME group (53.0%) than in BME (28.4%) or CsA (25.5%) groups. Posttransplant lymphoproliferative disorder (PTLD) only occurred in the AME group. In kidney transplant patients, the BME group preserved the clinical advantage of comparable acute rejection rates, improved renal function and a lower incidence of IF/TA versus CsA, and with similar rates of serious infection and no PTLD.

Five-year outcomes in kidney transplant patients converted from cyclosporine to everolimus: the randomized ZEUS study

ZEUS study was an open-label, 12-month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five-year follow-up data were available for 245/269 patients (91.1%) who completed the core 12-month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m(2) with everolimus versus 60.9 mL/min/1.73 m(2) with CsA; the mean difference was 5.3 mL/min/1.73 m(2) in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent-to-treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m(2) (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy-proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long-term graft function.

Novel once-daily extended-release tacrolimus (LCPT) versus twice-daily tacrolimus in de novo kidney transplants: one-year results of Phase III, double-blind, randomized trial

This Phase III randomized trial examined efficacy and safety of a novel once-daily extended-release tacrolimus formulation (LCP-Tacro [LCPT]) versus twice-daily tacrolimus in de novo kidney transplantation. Primary efficacy end point was proportion of patients with treatment failure (death, graft failure, biopsy-proven acute rejection or lost to follow-up) within 12 months. Starting doses were, LCPT: 0.17 mg/kg/day and tacrolimus twice-daily: 0.1 mg/kg/day; 543 patients were randomized, LCPT: n = 268; tacrolimus twice-daily: n = 275. At 12 months treatment failure was LCPT: 18.3% and tacrolimus twice-daily: 19.6%; the upper 95% CI of the treatment difference was +5.27%, below the predefined +10% noninferiority criteria. There were no significant differences in the incidence of individual efficacy events or adverse events. Target tacrolimus trough levels were more rapidly achieved in the LCPT group. Following initial dose, 36.6% of patients in the LCPT group had rapidly attained trough levels within 6-11 ng/mL versus 18.5% of tacrolimus twice-daily patients; majority of tacrolimus twice-daily patients (74.7%) had troughs <6 ng/mL compared with 33.5% in the LCPT group. Overall, cumulative study dose was 14% lower for LCPT. Results suggest that use of once-daily LCPT in de novo kidney transplantation is efficacious and safe. Lower LCPT dose reflects the improved absorption provided by the novel formulation.

Proceedings from an international consensus meeting on posttransplantation diabetes mellitus: recommendations and future directions

A consensus meeting was held in Vienna on September 8-9, 2013, to discuss diagnostic and therapeutic challenges surrounding development of diabetes mellitus after transplantation. The International Expert Panel comprised 24 transplant nephrologists, surgeons, diabetologists and clinical scientists, which met with the aim to review previous guidelines in light of emerging clinical data and research. Recommendations from the consensus discussions are provided in this article. Although the meeting was kidney-centric, reflecting the expertise present, these recommendations are likely to be relevant to other solid organ transplant recipients. Our recommendations include: terminology revision from new-onset diabetes after transplantation to posttransplantation diabetes mellitus (PTDM), exclusion of transient posttransplant hyperglycemia from PTDM diagnosis, expansion of screening strategies (incorporating postprandial glucose and HbA1c) and opinion-based guidance regarding pharmacological therapy in light of recent clinical evidence. Future research in the field was discussed with the aim of establishing collaborative working groups to address unresolved questions. These recommendations are opinion-based and intended to serve as a template for planned guidelines update, based on systematic and graded literature review, on the diagnosis and management of PTDM.

Efficacy of sotrastaurin plus tacrolimus after de novo kidney transplantation: randomized, phase II trial results

Sotrastaurin, a novel immunosuppressant, blocks early T cell activation through protein kinase C inhibition. Efficacy and safety of sotrastaurin with tacrolimus were assessed in a dose-ranging non-inferiority study in renal transplant recipients. A total of 298 patients were randomized 1:1:1:1 to receive sotrastaurin 100 (n = 77; discontinued in December 2011) or 200 mg (n = 73) b.i.d. plus standard tacrolimus (sTAC; 5-12 ng/mL), sotrastaurin 300 mg (n = 75) b.i.d. plus reduced tacrolimus (rTAC; 2-5 ng/mL) or enteric-coated mycophenolic acid (MPA) plus sTAC (n = 73); all patients received basiliximab and corticosteroids. Composite efficacy failure (treated biopsy-proven acute rejection ≥ grade IA, graft loss, death or loss to follow up) rates at Month 12 were 18.8%, 12.4%, 10.9% and 14.0% for the sotrastaurin 100, 200 and 300 mg, and MPA groups, respectively. The median estimated glomerular filtration rates were 55.7, 53.3, 64.9 and 59.2 mL/min, respectively. Mean heart rates were faster with higher sotrastaurin doses and discontinuations due to adverse events and gastrointestinal adverse events were more common. Fewer patients in the sotrastaurin groups experienced leukopenia than in the MPA group (1.3-5.5% vs. 16.5%). Sotrastaurin 200 and 300 mg had comparable efficacy to MPA in prevention of rejection with no significant difference in renal function between the groups.

Sotrastaurin in calcineurin inhibitor-free regimen using everolimus in de novo kidney transplant recipients

Sotrastaurin, a novel selective protein-kinase-C inhibitor, inhibits early T cell activation via a calcineurin-independent pathway. Efficacy and safety of sotrastaurin in a calcineurin inhibitor-free regimen were evaluated in this two-stage Phase II study of de novo kidney transplant recipients. Stage 1 randomized 131 patients (2:1) to sotrastaurin 300 mg or cyclosporine A (CsA). Stage 2 randomized 180 patients (1:1:1) to sotrastaurin 300 or 200 mg or CsA. All patients received basiliximab, everolimus (EVR) and prednisone. Primary endpoint was composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, death or lost to follow-up. Main safety assessment was estimated glomerular filtration rate (eGFR) by MDRD-4 at Month 12. Composite efficacy failure rates at 12 months were higher in sotrastaurin arms (Stage 1: 16.5% and 10.9% for sotrastaurin 300 mg and CsA; Stage 2: 27.2%, 34.5% and 19.4% for sotrastaurin 200 mg, 300 mg and CsA). eGFR was significantly better in sotrastaurin groups versus CsA at most time points, except at 12 months. Gastrointestinal and cardiac adverse events were more frequent with sotrastaurin. Higher treatment discontinuation, deaths and graft losses occurred with sotrastaurin 300 mg. Sotrastaurin combined with EVR showed higher efficacy failure rates and some improvement in renal allograft function compared to a CsA-based therapy.

Neutrophil gelatinase-associated lipocalin: pathophysiology and clinical applications

Neutrophil gelatinase-associated lipocalin (NGAL), a 25 kDa protein produced by injured nephron epithelia, is one of the most promising new markers of renal epithelial injury. In contrast to serum creatinine and urinary output, which are the measures of kidney function, NGAL is specifically induced in the damaged nephron and then released into blood and urine, where it can be readily measured. Careful proof-of-concept studies using defined animal models have uncovered the sources and trafficking of NGAL in acute kidney injury (AKI) and have addressed the contributions of renal and non-renal sources. Clinical studies indicate that NGAL, unlike creatinine, is a marker responsive to tissue stress and nephron injury, but less so to adaptive hemodynamic responses. In certain clinical settings, NGAL is an earlier marker compared with serum creatinine. In addition, clinical studies have shown that NGAL is a powerful predictor of poor clinical outcomes, which can be used to risk stratify patients when combined with serum creatinine. NGAL has important limitations, including its responsiveness in systemic inflammation, which is partially uncoupled from its response to kidney injury and which needs to be considered when interpreting NGAL results clinically. This review covers the biology and pathophysiology of NGAL and summarizes the results of the growing body of clinical studies that have addressed the utility of NGAL in the early diagnosis of AKI, in the distinction of intrinsic AKI and in the prognostic assessment of broad patient populations.

Conversion from twice-daily tacrolimus to once-daily extended release tacrolimus (LCPT): the phase III randomized MELT trial

Phase III noninferiority trial examining efficacy and safety of converting stable renal transplant recipients from twice-daily tacrolimus to a novel extended-release once-daily tacrolimus formulation (LCPT) with a controlled agglomeration technology. Controls maintained tacrolimus twice daily. The primary efficacy endpoint was proportion of patients with efficacy failures (death, graft failure, locally read biopsy-proven acute rejection [BPAR], or loss to follow-up) within 12 months. Starting LCPT dose was 30% lower (15% for blacks) than preconversion tacrolimus dose; target trough levels were 4-15 ng/mL. A total of 326 patients were randomized; the mITT population (n = 162 each group) was similar demographically in the two groups. Mean daily dose of LCPT was significantly (p < 0.0001) lower than preconversion tacrolimus dose at each visit; mean trough levels between groups were similar. There were four efficacy failures in each group; safety outcomes were similar between groups. Frequency of premature study drug discontinuation was LCPT: 12% versus tacrolimus twice daily: 5% (p = 0.028). LCPT demonstrated noninferiority to tacrolimus twice daily in efficacy failure rates. LCPT may offer a safe and effective alternative for converting patients to a once-daily formulation. Compared to currently available tacrolimus formulation, LCPT requires lower doses to achieve target trough levels.

Randomized phase 2b trial of tofacitinib (CP-690,550) in de novo kidney transplant patients: efficacy, renal function and safety at 1 year

In this Phase 2b study, 331 low-to-moderate risk de novo kidney transplant patients (approximately 60% deceased donors) were randomized to a more intensive (MI) or less intensive (LI) regimen of tofacitinib (CP-690, 550), an oral Janus kinase inhibitor or cyclosporine (CsA). All patients received basiliximab induction, mycophenolic acid and corticosteroids. Primary endpoints were: incidence of biopsy-proven acute rejection (BPAR) with a serum creatinine increase of ≥0.3 mg/dL and ≥20% (clinical BPAR) at Month 6 and measured GFR at Month 12. Similar 6-month incidences of clinical BPAR (11%, 7% and 9%) were observed for MI, LI and CsA. Measured GFRs were higher (p < 0.01) at Month 12 for MI and LI versus CsA (65 mL/min, 65 mL/min vs. 54 mL/min). Fewer (p < 0.05) patients in MI or LI developed chronic allograft nephropathy at Month 12 compared with CsA (25%, 24% vs. 48%). Serious infections developed in 45%, 37% and 25% of patients in MI, LI and CsA, respectively. Anemia, neutropenia and posttransplant lymphoproliferative disorder occurred more frequently in MI and LI compared with CsA. Tofacitinib was equivalent to CsA in preventing acute rejection, was associated with improved renal function and less chronic allograft histological injury, but had side-effects at the doses evaluated.

Conversion from cyclosporine to everolimus at 4.5 months posttransplant: 3-year results from the randomized ZEUS study

The long-term effect of conversion from calcineurin inhibitor (CNI) therapy to an mTOR inhibitor requires clarification. Following completion of the 12-month, open-label, multicenter ZEUS study, in which 300 kidney transplant recipients were randomized to continue cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant, outcomes were assessed at month 36 (n = 284; 94.7%). CNI therapy was reintroduced in 28.4% of everolimus patients by month 36. The primary efficacy endpoint, estimated glomerular filtration rate (Nankivell, ANCOVA) was significantly higher with everolimus versus the CsA group at month 24 (7.6 mL/min/1.73 m(2) , 95%CI 4.3, 11.0 mL/min/1.73 m(2) ; p < 0.001) and month 36 (7.5 mL/min/1.73 m(2) , 95%CI 3.6, 11.4 mL/min/1.73 m(2) ; p < 0.001). The incidence of biopsy-proven acute rejection from randomization to month 36 was 13.0% in the everolimus arm and 4.8% in the CsA arm (p = 0.015). Patient and graft survival, as well as incidences of malignancy, severe infections and hospitalization, were similar between groups. Kidney transplant patients who are converted from CsA to everolimus at month 4.5 and who remain on everolimus thereafter may achieve a significant improvement in renal function that is maintained to 3 years. There was a significantly higher rate of rejection in the everolimus arm but this did not exert a deleterious effect by 3 years posttransplant.

Donor-specific HLA antibodies in a cohort comparing everolimus with cyclosporine after kidney transplantation

Donor-specific HLA antibodies (DSA) have a negative impact on kidney graft survival. Therefore, we analyzed the occurrence of DSA and antibody-mediated rejection (AMR) in patients from two prospective randomized trials in our center. At 3-4.5 months posttransplant 127 patients were randomized to continue cyclosporine or converted to everolimus therapy. The presence of DSA was prospectively assessed using Luminex assays. AMR was defined according to the Banff 2009 classification. Antibody screening was available in 126 patients with a median follow-up of 1059 days. Seven out of 65 (10.8%) patients on cyclosporine developed DSA after a median of 991 days. In comparison, 14/61 patients (23.0%) randomized to everolimus developed DSA after 551 days (log-rank: p = 0.048). Eight patients on everolimus compared to two patients on cyclosporine developed AMR (log-rank: p = 0.036). Four of 10 patients with AMR-all in the everolimus group-lost their graft. A multivariate regression model revealed everolimus, >3 mismatches and living donor as significant risk factors for DSA. Acute rejection within the first year, >3 mismatches, everolimus and living donor were independent risk factors for AMR. This single center analysis demonstrates for the first time that everolimus-based immunosuppression is associated with an increased risk for the development of DSA and AMR.