The reduction of left ventricular hypertrophy after renal transplantation is not influenced by the immunosuppressive regimen

BACKGROUND

Cardiovascular (CV) disease is the first cause of death after kidney transplantation. Left ventricular hypertrophy (LVH) is one of the main CV risk factors. It has been reported that the antiproliferative properties of everolimus (EVE) treatment may decrease left ventricular mass. The aim of this study was to evaluate the evolution of LVH in two groups of kidney transplant recipients receiving immunosuppressive treatment with low-dose calcineurin inhibitor (CNI) + EVE or CNI + mycophenolate mofetil (MMF).

METHODS

We evaluated 104 patients of mean age 47.5 ± 13.1 years who underwent kidney transplantation between January 2006 and December 2009 pretransplant by echocardiography, which was repeated every year for 3 years during which all patients continued the initial therapy. Over the 3-year period 76 subjects were treated with MMF, and 28 with EVE. We recorded left ventricular end-diastolic diameter (LVEDD), interventricular septum thickness in diastole (IVSTD), left ventricular posterior wall thickness in diastole (LVPWD), left ventricular end-diastolic volume and end-systolic volume during the follow-up echocardiographic evaluations.

RESULTS

No differences in the evolution of the echocardiographic parameters were observed between the two groups-MMF versus EVE group: LVEDD, 50.3 ± 5.1 versus 51.2 ± 6.7 mm; IVSTD, 11.2 ± 1.9 versus 11.3 ± 2 mm; LVPWD, 10.2 ± 1.9 versus 10.5 ± 1.7 mm; relative wall thickness, 0.041 ± 0.08 versus 0.42 ± 0.08; ejection fraction, 63 ± 6% versus 61 ± 5%; and left ventricular mass index, 113 ± 28.9 versus 121.9 ± 39.4 g/m(2), respectively. Compared with pretransplant echocardiographic evaluations, similar reductions in left ventricular mass index were noted in both groups after transplantation.

CONCLUSIONS

We observed that after renal transplantation there was a reduction of the LVH respect to the pretransplant dialytic status. The two immunosuppressive regimen did not influence the evolution of post-transplant LVH.

The current role of endourologic management of renal transplantation complications

Introduction. Complications following renal transplantation include ureteral obstruction, urinary leak and fistula, urinary retention, urolithiasis, and vesicoureteral reflux. These complications have traditionally been managed with open surgical correction, but minimally invasive techniques are being utilized frequently. Materials and Methods. A literature review was performed on the use of endourologic techniques for the management of urologic transplant complications. Results. Ureterovesical anastomotic stricture is the most common long-term urologic complication following renal transplantation. Direct vision endoureterotomy is successful in up to 79% of cases. Urinary leak is the most frequent renal transplant complication early in the postoperative period. Up to 62% of patients have been successfully treated with maximal decompression (nephrostomy tube, ureteral stent, and Foley catheter). Excellent outcomes have been reported following transurethral resection of the prostate shortly after transplantation for patients with urinary retention. Vesicoureteral reflux after renal transplant is common. Deflux injection has been shown to resolve reflux in up to 90% of patients with low-grade disease in the absence of high pressure voiding. Donor-gifted and de novo transplant calculi may be managed with shock wave, ureteroscopic, or percutaneous lithotripsy. Conclusions. Recent advances in equipment and technique have allowed many transplant patients with complications to be effectively managed endoscopically.

mTORC1 and p53: clash of the gods?

A balance must be struck between cell growth and stress responses to ensure that cells proliferate without accumulating damaged DNA. This balance means that optimal cell proliferation requires the integration of pro-growth and stress-response pathways. mTOR (mechanistic target of rapamycin) is a pleiotropic kinase found in complex 1 (mTORC1).The mTORC1 pathway governs a response to mitogenic signals with high energy levels to promote protein synthesis and cell growth. In contrast, the p53DNA damage response pathway is the arbiter of cell proliferation, restraining mTORC1 under conditions of genotoxic stress. Recent studies suggest a complicated integration of these pathways to ensure successful cell growth and proliferation without compromising genome maintenance. Deciphering this integration could be key to understanding the potential clinical usefulness of mTORC1 inhibitors like rapamycin. Here we discuss how these p53-mTORC1 interactions might play a role in the suppression of cancer and perhaps the development of cellular senescence and organismal aging.

PI3Kδ inhibition augments the efficacy of rapamycin in suppressing proliferation of Epstein-Barr virus (EBV)+ B cell lymphomas

Posttransplant lymphoproliferative disorder (PTLD) continues to be a devastating and potentially life-threatening complication in organ transplant recipients. PTLD is associated with EBV infection and can result in malignant B cell lymphomas. Here we demonstrate that the PI3K/Akt/mTOR pathway is highly activated in EBV+ B cell lymphoma lines derived from patients with PTLD. Treatment with the mTORC1 inhibitor Rapamycin (RAPA) partially inhibited the proliferation of EBV+ B cell lines. Resistance to RAPA treatment correlated with high levels of Akt phosphorylation. An mTORC1/2 inhibitor and a PI3K/mTOR dual inhibitor suppressed Akt phosphorylation and showed a greater anti-proliferative effect on EBV+ B lymphoma lines compared to RAPA. EBV+ B cell lymphoma lines expressed high levels of PI3Kδ. We demonstrate that PI3Kδ is responsible for Akt activation in EBV+ B cell lymphomas, and that selective inhibition of PI3Kδ by either siRNA, or a small molecule inhibitor, augmented the anti-proliferative effect of RAPA on EBV+ B cell lymphomas. These results suggest that PI3Kδ is a novel, potential therapeutic target for the treatment of EBV-associated PTLD and that combined blockade of PI3Kδ and mTOR provides increased efficacy in inhibiting proliferation of EBV+ B cell lymphomas.

Tacrolimus plus mycophenolate mofetil vs. cyclosporine plus everolimus in deceased donor kidney transplant recipients: three-yr results of a single-center prospective clinical trial

We compared in kidney transplantation two immunosuppressive regimens: tacrolimus plus mycophenolate mofetil (MMF) (TAC) and everolimus plus low-dose cyclosporine (EVE). Sixty consecutive patients received TAC (30 patients) or EVE (30 patients) as immunosuppressive regimen; all subjects also received induction with basiliximab and corticosteroids. After three-yr follow-up, no difference was found in patient and graft survival (PTS: TAC: 97% vs. EVE: 100%; GS: TAC: 93% vs. EVE: 93%). The incidence of acute rejection was higher in the EVE group but the difference was not statistically significant (17% vs. 23%, p = ns). Patients in EVE showed higher serum cholesterol (205 ± 41 vs. 235 ± 41 mg/dL, p = 0.0012) and lower hemoglobin concentration (13.6 ± 1.4 vs. 12.4 ± 1.9, p = 0.01). Renal function was not significantly different in the two groups (3 Y creatinine: TAC 1.4 ± 0.8 vs. EVE 1.6 ± 0.8 mg/dL, p = ns). Treatment discontinuation was higher in the EVE group (TAC 17 vs. EVE 36%, p = ns). Our data show that in the middle-term follow-up, an immunosuppressive regimen with tacrolimus plus MMF has a similar efficacy and safety profile in comparison with the combination of low-exposure cyclosporine plus everolimus. Further follow up could evidence the benefits related to the anti-proliferative effects of everolimus.

Use of cold-stored vein allografts for venous reconstruction during pancreaticoduodenectomy

INTRODUCTION

Venous resections and reconstructions of portal vein and/or superior mesenteric vein in course of pancreaticoduodenectomy are becoming a common practice and many surgical options have been described, from simple tangential resection and venorrhaphy to large segmental resections followed by interposition grafting. The aim of this study was to report the first experience of using fresh cadaveric vein allografts for venous reconstruction during pancreaticoduodenectomy focusing on technical feasibility and postoperative outcomes.

METHODS

From January 2001 to October 2012, out of 151 patients undergoing pancreaticoduodenectomy for pancreatic head tumor, 22 (14.5 %) received a vascular resection of the mesentericoportal axis. In five of these patients, vascular reconstruction was accomplished by using cold-stored venous allografts of iliac and femoral veins from donor cadaver. Patients' data, surgical techniques, and clinical outcomes were analyzed.

RESULTS

Five patients undergoing pancreaticoduodenectomy were selected to receive a vascular reconstruction using a fresh venous allograft for patch closure in three cases, conduit interposition in one case and a Y-shaped graft in the last case. No graft thrombosis or stenosis occurred postoperatively and at long-term follow-up. Mortality rate was zero.

CONCLUSION

The use of fresh vein allografts is a feasible and effective technique for venous reconstruction during pancreaticoduodenectomy. However, prospective surveys including large cohorts of patients are necessary to confirm these results.

Outcomes of Pregnancies Fathered by Solid-Organ Transplant Recipients Exposed to Mycophenolic Acid Products

Context

In women, exposure to mycophenolic acid products during pregnancy results in an increase in both miscarriages and birth defects in the live born.

Objective

To describe the outcomes of pregnancies fathered by transplant recipients who were being maintained on mycophenolic acid products at the estimated time of conception and compare these pregnancies with pregnancies in the general population.

Methods

Data were collected by the National Transplantation Pregnancy Registry via questionnaires, telephone interviews, and medical records.

Results

One hundred fifty-two male transplant recipients with exposure to mycophenolic acid products fathered 205 pregnancies (208 outcomes, including 3 pairs of twins). Pregnancy outcomes included 194 live births with a prematurity rate of 10.8%, 14 spontaneous abortions, and no therapeutic abortions or stillbirths. Among the live births, 6 malformations were reported, for an incidence of 3.1%. No pattern of malformations was identified.

Conclusion

The outcomes of pregnancies fathered by transplant recipients treated with mycophenolic acid products appear similar to outcomes in the general population.

Diagnosis, management and treatment of glucometabolic disorders emerging after kidney transplantation: a position statement from the Nordic Transplantation Societies

After successful solid organ transplantation, new-onset diabetes (NODAT) is reported to develop in about 15-40% of the patients. The variation in incidence may partly depend on differences in the populations that have been studied and partly depend on the different definitions of NODAT that have been used. The diagnosis was often based on 'the use of insulin postoperatively', 'oral agents used', random glucose monitoring and a fasting glucose value between 7 and 13 mmol/l (126-234 mg/dl). Only few have used a 2-h glucose tolerance test performed before transplantation. There is a huge variation in the literature regarding risk factors for developing NODAT. They can be divided into factors related to glucose metabolism or to patient demographics and the latter into modifiable and nonmodifiable. Screening for risk factors should start early and be re-evaluated while being on the waitlist. Patients on the waiting list for renal transplantation and transplanted patients share many characteristics in having hyperglycaemia, disturbed insulin secretion and increased insulin resistance. We present guidelines for early risk factor assessment and a screening/treatment strategy for disturbed glucose metabolism, both before and after transplantation. The aim was to avoid the increased cardiovascular disease and mortality rates associated with NODAT.

Evaluation of nutrient intake in early post kidney transplant recipients

The purpose of our study was to evaluate the dietary intake of kidney transplant recipients (KTRs) and assess oral intake related nutrition problems. Fifty patients who had undergone kidney transplantation were included: 24 males, 26 females. The mean age was 46.8 ± 11.2 years, height was 161.3 ± 8.3 cm, and body weight was 60.5 ± 8.7 kg. We conducted nutrition education based on the diet guideline for KTRs (energy 32 kcal/kg of ideal body weight [IBW], protein 1.3 g/kg of IBW) and neutropenic diet guideline before discharge. Dietary intake of the patients at 1 month after transplantation was investigated by 3-day food records. Body weight and laboratory values for nutritional status and graft function were also collected. Body weight was significantly decreased from admission to discharge. Body weight from discharge to 1 month and 3 months after transplantation was increased but was not significant. Biochemical measurements were generally improved but the number of patients with hypophosphatemia increased. The daily dietary intake of energy and protein was adequate (33.1 kcal/kg, 1.5 g/kg, respectively). However, the dietary intake of calcium, folate, and vitamin C did not meet the Korean Recommended Nutrient Intake of vitamins and minerals (86.8%, 62.4%, and 88.0%, respectively). Patients with low intake of calcium, folate, and vitamin C presented low intake in milk and dairy products, vegetables, and fruits, and these foods were related to restricted food items in neutropenic diet. More attention should be paid on improving quality of diet, and reconsideration of present neutropenic diet guideline is necessary. These results can be used to establish evidence-based medical nutrition therapy guideline for KTRs.

Value of routine voiding cystourethrography after renal transplantation

The impact of vesicoureteral reflux (VUR) on renal allograft outcomes is debatable, with small cohort studies reporting controversial results. The objective of this retrospective study was to evaluate long-term clinical effects of early VUR in a large cohort of kidney transplant patients. Posttransplantation voiding cystourethrography was used to evaluate 646 consecutive kidney transplant recipients before discharge. The study endpoints included VUR grade, death-censored graft or patient survival, renal function, proteinuria and occurrence of urinary tract infections (UTIs). Of the 646 recipients, 263 (40.7%) were diagnosed with VUR. VUR grade II was most common (19.8%), followed by grades III (10.2%), I (7.9%) and IV (2.8%). VUR was less common in transplantations performed by experienced compared to inexperienced surgeons (36% vs. 48%; p = 0.004). VUR did not affect death-censored graft or patient survival and was not associated with proteinuria or occurrence of UTIs. Patients with VUR had a lower eGFR at 1 year after transplantation than did patients without VUR (60 vs. 52 mL/min/1.73 m(2) ; p = 0.02), although this difference was not observed at 3 and 5 years after transplantation. We conclude that early VUR, a common finding among renal transplant patients, may not have a meaningful impact on long-term transplant outcomes.

Chronic mTOR inhibition by rapamycin induces muscle insulin resistance despite weight loss in rats

BACKGROUND AND PURPOSE

mTOR inhibitors are currently used as immunosuppressants in transplanted patients and as promising anti-cancer agents. However, new-onset diabetes is a frequent complication occurring in patients treated with mTOR inhibitors such as rapamycin (Sirolimus). Here, we investigated the mechanisms associated with the diabetogenic effects of chronic Sirolimus administration in rats and in in vitro cell cultures.

EXPERIMENTAL APPROACH

Sirolimus was administered to rats fed either a standard or high-fat diet for 21 days. Metabolic parameters were measured in vivo and in ex vivo tissues. Insulin sensitivity was assessed by glucose tolerance tests and euglycaemic hyperinsulinaemic clamps. Rapamycin effects on glucose metabolism and insulin signalling were further evaluated in cultured myotubes.

KEY RESULTS

Sirolimus induced a decrease in food intake and concomitant weight loss. It also induced specific fat mass loss that was independent of changes in food intake. Despite these beneficial effects, Sirolimus-treated rats were glucose intolerant, hyperinsulinaemic and hyperglycaemic, but not hyperlipidaemic. The euglycaemic hyperinsulinaemic clamp measurements showed skeletal muscle is a major site of Sirolimus-induced insulin resistance. At the molecular level, long-term Sirolimus administration attenuated glucose uptake and metabolism in skeletal muscle by preventing full insulin-induced Akt activation and altering the expression and translocation of glucose transporters to the plasma membrane. In rats fed a high-fat diet, these metabolic defects were exacerbated, although Sirolimus-treated animals were protected from diet-induced obesity.

CONCLUSIONS AND IMPLICATIONS

Taken together, our data demonstrate that the diabetogenic effect of chronic rapamycin administration is due to an impaired insulin action on glucose metabolism in skeletal muscles.

Emergency endovascular repair in a patient with abdominal aortic aneurysm with pelvic transplant kidneys: case report

Abdominal aortic aneurysms after a kidney transplant are becoming treated more frequently owing to the extension of renal transplant in severely arteriosclerotic older patients. Renal transplant recipients with autosomal dominant polycystic kidney disease are prone to develop abdominal aortic aneurysms. We present the case of a ruptured abdominal aortic aneurysm that occurred in a renal transplant patient with autosomal dominant polycystic kidney disease. The patient was treated with emergency endovascular repair because open surgery could not be performed successfully owing to the presence of massive polycystic native kidneys and a liver that was occupying the entire peritoneal cavity. His postoperative course was uneventful without complications. The important lessons to be learned from our case are 2-fold: (1) Autosomal dominant polycystic kidney disease renal transplant recipients should be screened annually for abdominal aortic aneurysms to prevent ruptures and (2), emergency endovascular repair may be a preferred treatment in renal transplant recipients owing to its low surgical risk and success.

A CD3+ count-based thymoglobulin induction regimen permits delayed introduction of calcineurin inhibitors in kidney transplantation

BACKGROUND

Withholding calcineurin inhibitors (CNIs) can be considered when graft function is inadequate following kidney transplantation (KT). Thymoglobulin (rATG) can be used to prevent acute rejection while CNIs are being withheld. Here, we report our results of a novel CNI-sparing induction protocol, which utilizes a CD3+ cell count-based rATG treatment regimen when delayed graft function (DGF) develops in the immediate postoperative period.

METHODS

In a cohort of 153 consecutive deceased-donor KT recipients, all received a single intraoperative dose of basiliximab; 84 subsequently developed DGF and therefore received rATG (rATG+ group), while 69 demonstrated immediate graft function and received CNIs (rATG- group).

RESULTS

In the rATG+ group, mean duration of therapy was 8.5±6.0 d, permitting CNI initiation to be delayed until postoperative day 10.3±6.2. Cumulative dose of rATG was only 5.1±4.5 mg/kg while targeting CD3+ counts of ≤30 cells/mm3. CD3+ counts were reduced to a mean of 16.7±17.0 cells/mm3 during therapy. At one yr, patient and graft survival rates were 97.6% and 92.9%, respectively, while the frequency of infections and malignancies were not significantly increased compared to the rATG- group.

CONCLUSION

A unique induction regimen successfully delayed CNI initiation by using modest doses of rATG to deplete CD3+ cells, while yielding excellent long-term graft outcome without increased risk of infection or malignancy.

The importance of different immunosuppressive regimens in the development of posttransplant diabetes mellitus

Solid-organ transplantation is the optimal long-term treatment for most patients with end-stage organ failure. After solid-organ transplantation, short-term graft survival significantly improved (1). However, due to chronic allograft nephropathy and death with functioning graft, long-term survival has not prolonged remarkably (2). Posttransplant immunosuppressive medications consist of one of the calcineurin inhibitors in combination with mycophenolate mofetil (MMF) or azathioprine (Aza) and steroids. All of them have different adverse effects, among which posttransplant diabetes mellitus (PTDM) is an independent risk factor for cardiovascular (CV) events and infections causing the death of many transplant patients and it may directly contribute to graft failure (3). According to the criteria of the American Diabetes Association (4), diabetes mellitus (DM) is defined by symptoms of diabetes (polyuria and polydipsia and weight loss) plus casual plasma glucose concentration ≥ 11.1 mmol/L or fasting plasma glucose (FPG) ≥ 7.0 mmol/L or 2-h plasma glucose level ≥ 11.1 mmol/L following oral glucose tolerance test (OGTT). This metabolic disorder occurring as a complication of organ transplantation has been recognized for many years. PTDM, which is a combination of decreased insulin secretion and increased insulin resistance, develops in 4.9/15.9% of liver transplant patients, in 4.7/11.5% of kidney recipients, and in 15/17.5% of heart and lung transplants [cyclosporine A (CyA)/tacrolimus (Tac)-based regimen, respectively] (5). Risk factors of PTDM can be divided into non-modifiable and modifiable ones (6), among which the most prominent is the immunosuppressive therapy being responsible for 74% of PTDM development (7). Emphasizing the importance of the PTDM, numerous studies have determined the long-term outcome. On the basis of these studies, graft and patient survival is tendentiously (8) or significantly (9, 10) decreased for those developing PTDM.

Long-term experience with everolimus in kidney transplantation in the United States

BACKGROUND

Limited long-term data exist on US kidney transplant patients who have received everolimus at time of transplantation.

METHODS

Using data from the United Network for Organ Sharing/Organ Procurement Transplant Network database, we described patient characteristics and outcomes among adult patients who received a kidney transplant between 1998 and 2007 and received everolimus maintenance immunosuppression (n = 392) at time of discharge. Outcomes included acute rejection, new-onset diabetes posttransplant, primary graft failure, and serum creatinine. We included single-organ, first-time transplants between 1998 and 2007 as a reference group.

RESULTS

Primary graft survival at 3 and 5 years posttransplantation was 87.2% ± 2.1% (95% confidence interval [CI]: 82.5%-90.7%) and 77.4% ± 3.0% (95% CI: 70.8%-82.7%), respectively, in the everolimus-treated group. Improved graft survival with everolimus seemed to be more pronounced in recipients of deceased donor transplants despite the fact that everolimus-treated patients quantitatively had a higher rate of acute rejection at 3 years posttransplant versus the reference group.

CONCLUSION

Although the incidence of acute rejection was slightly higher in the everolimus-treated patients, graft survival at 3 and 5 years posttransplantation favored everolimus, with the effect being particularly notable in the recipients who received deceased donor renal transplants.

A retrospective 12-month study of conversion to everolimus in lung transplant recipients

BACKGROUND

Everolimus has potent antifibrotic effects that may potentially affect the clinical course of bronchiolitis obliterans syndrome (BOS) or provide nephroprotective immunosuppressive regimens for lung transplantation.

METHODS

We retrospectively assessed the 12-month outcomes of the conversion to everolimus among lung recipients in six Spanish centers.

RESULTS

From March 2005 to December 2007, 65 lung recipients who were at a mean posttransplantation time of 10.2 ± 7.9 months were converted to everolimus, mainly because of BOS (64.6%) or renal insufficiency (RI; 12.3%). The initial dose of everolimus was 1.9 ± 0.6 mg/d and the mean blood trough levels were stable over time (6.4 ± 2.8 ng/mL at 12 months). Conversion to everolimus allowed us to eliminate the calcineurin inhibitor (CNI) in 21% of patients. Among the overall population, the forced expiratory volume at 1 second (FEV(1)) and renal function remained stable. Mean FEV(1) did not change among the 35 (81%) patients surviving BOS at 12 months: preconversion FEV(1): 1.449.5 ± 641.9 mL vs 12-month FEV(1): 1420.0 ± 734.6 mL (P = .866). There was a significant improvement in renal function among the RI patients with mean glomerular filtration rates of 42.2 ± 15.2 mL/min/1.73 m(2) (P = .043) at 6 and 44.4 ± 18.8 mL/min/1.73 m(2) at 12 months, (P = .063) and a decrease in the use of CNIs from 1% of RI patients preconversion to 57% at 6 and 75% at 12 months. With a mean of 8.1- months follow-up (range: 1-31.3) overall survival was 84.6% at 1 year and 50% at 22.3 months. Progressive BOS was the main cause of death. Reasons for everolimus discontinuation were patient death (n = 10), lack of efficacy (n = 4), gastrointestinal adverse events (n = 2), and edema (n = 2).

CONCLUSIONS

BOS and RI were the main indications for conversion to everolimus among lung recipients. Conversion to everolimus improved renal function among patients converted because of RI. The present results were inconclusive regarding effects of everolimus on BOS.

Leptin, insulin resistance, and metabolic changes 5 years after renal transplantation

OBJECTIVE

To evaluate leptin, insulin resistance (IR), and changes in body composition and lipid profile within 5 years after renal transplantation.

DESIGN

Longitudinal study.

SETTING

Hospital de Clínicas de Porto Alegre/RS, Brazil.

SUBJECTS

Thirty-two renal transplant recipients were followed up for 5 years after transplantation.

METHODS

Data were collected at transplantation time (T₁) and after 3 months (T₂), 1 year (T₃), and 5 years (T₄). Leptin serum levels, IR assessed by homeostasis model assessment (HOMA) index, lipid profile, and anthropometric measurements were analyzed. Data were compared with a control group at baseline.

RESULTS

At T₁, pretransplant patients had leptin levels (ng/mL) (11.9 [9.2 to 25.2]) higher than the control group (7.7 [5.2 to 9.9]; P < .0001). After transplantation, levels decreased at T₂ and T₃, but increased at T₄ to values similar to those seen at T₁ (T₄: 9.2 [5.7 to 21]; P = 1). HOMA also decreased at T₂, but increased at T₄ to identical levels (T₁: 2.1 [1.63 to 2.23], T₄: 2.1 [1.6 to 2.85]; P = 1). No significant changes in body fat percentage (BF%) were observed; however, the arm muscle circumference increased significantly at T₄ (P < .0001). At T₂, total cholesterol, triglycerides, and low-density lipoprotein cholesterol increased, whereas at T₄, lipid profile moved toward T₁ levels. By linear regression analysis, gender, BF%, and HOMA were independent predictors of leptin levels. A trend toward higher body mass index was observed in woman who also presented higher leptin and lower HOMA levels.

CONCLUSION

Leptin levels and HOMA decrease in the immediate posttransplant period and remain reduced for at least 1 year. Five years post transplantation, leptin, IR, BF%, and lipids have a profile similar to those in the pretransplant period. This metabolic profile is possibly associated with the elevated incidence of cardiovascular diseases observed in the late posttransplant period.

Prevention and management of transplant-associated diabetes

INTRODUCTION

New-onset diabetes after transplantation (NODAT) is considered to be a major cause of cardiovascular disease and death among patients with a functioning allograft. A major challenge is to reduce the incidence of NODAT and to treat it optimally once it has occurred.

AREAS COVERED

This review presents current data on how to prevent NODAT in patients at risk, with a focus on modifications in the immunosuppressive regimen. Current suggestions for detection and treatment of NODAT are also presented.

EXPERT OPINION

Prevention of NODAT is possible by assessing the patient's glycemic risk prior to transplantation and tailoring the treatment (e.g., choice and dosage of immunosuppressive agents) after transplantation. An oral glucose tolerance test is still the gold standard to detect NODAT in patients at risk (prediabetes) but algorithms can be used to select those who should be tested. The treatment of NODAT involves a broad approach on risk factors for cardiovascular events and graft loss. Future studies on the use of oral hypoglycemic agents in NODAT are still needed.

Immunosuppressant regimen based on sirolimus decreases aortic stiffness in renal transplant recipients in comparison to cyclosporine

Whether or not a cyclosporine A (CsA)-free immunosuppressant regimen based on sirolimus (SRL) prevents aortic stiffening and improves central hemodynamics in renal recipients remains unknown. Forty-four patients (48 ± 2 years) enrolled in the CONCEPT trial were randomized at week 12 (W12) to continue CsA or switch to SRL, both associated with mycophenolate mofetil. Carotid systolic blood pressure (cSBP), pulse pressure (cPP), central pressure wave reflection (augmentation index, AIx) and carotid-to-femoral pulse-wave velocity (PWV: aortic stiffness) were blindly assessed at W12, W26 and W52 together with plasma endothelin-1 (ET-1), thiobarbituric acid-reactive substances (TBARS) and superoxide dismutase (SOD) and catalase erythrocyte activities. At W12, there was no difference between groups. At follow-up, PWV, cSBP, cPP and AIx were lower in the SRL group. The difference in PWV remained significant after adjustment for blood pressure and eGFR. In parallel, ET-1 decreased in the SRL group, while TBARS, SOD and catalase erythrocyte activities increased in both groups but to a lesser extent in the SRL group. Our results demonstrate that a CsA-free regimen based on SRL reduces aortic stiffness, plasma endothelin-1 and oxidative stress in renal recipients suggesting a protective effect on the arterial wall that may be translated into cardiovascular risk reduction.

Sirolimus in pediatric renal transplantation

SRL, an mTOR inhibitor that inhibits cell cycle progression, represents an important alternative to CNIs, which are still the cornerstones of pediatric solid organ tx. Because there are still limited data on SRL use among pediatric solid organ recipients, further studies are needed to verify the efficacy and safety of SRL. It has unique pharmacokinetic characteristics concerning dosing intervals and reduction of the dose in combination with other immunosuppressants. SRL also has antineoplastic, antiviral, and antiatherogenic advantages over other immunosuppressive agents. The adverse effects of SRL including thrombocytopenia, hyperlipidemia, proteinuria, impaired wound healing, mouth ulcers, edema, male hypogonadism, TMA, and interstitial pneumonitis must be considered carefully in pediatric population. This article reviews the most recent data on SRL application in the field of pediatric renal tx.

Sirolimus therapy predisposes to new-onset diabetes mellitus after renal transplantation: a long-term analysis of various treatment regimens

PURPOSE

This retrospective analysis evaluated the impacts of sirolimus (SRL), cyclosporine (CsA), and steroids (S) on the occurrence, treatment, and complications of new-onset diabetes after transplantation (NODAT).

METHODS

We compared 4 groups: group 1, SRL plus full-exposure CsA/S (n = 118); group 2, full-exposure CsA/S/no SRL ± antiproliferative drug (n = 141); group 3, SRL plus reduced CsA exposure/S (n = 212); and group 4, no SRL/full-exposure CsA/S ± antiproliferative drug (n = 43).

RESULTS

NODAT rates reflected the level of CsA exposure; at 10 years 54% versus 30% for groups 1 versus 2 (P = .0001); at 5 years 30% versus 21% for Groups 3 versus 4 (P = .3); 81% of cases were detected within 1 year. The lower NODAT rate in group 3 reflected a benefit of reduced CsA exposure (P = .02; hazard ratio (HR), 1.006). Group 1 showed higher CsA (P = .0001) and lower SRL concentrations (P = .016) versus group 3. CsA exposure closely correlating with NODAT among group 1 (P = .0001) was the major difference between groups 1 and 3 (P = .04; HR, 0.97). Differences in steroid treatment did not play a significant role in NODAT. Comparing groups 1 and 2, SRL was an independent risk factor for NODAT (P = .004; HR, 3.5).

CONCLUSIONS

Our 10-year experience revealed SRL to be an etiologic agent for NODAT, displaying interactive, possibly pharmacokinetic, and pharmacodynamic effects with concomitant CsA in combination treatment.

New-onset diabetes after renal transplantation: diagnosis, incidence, risk factors, impact on outcomes, and novel implications

OBJECTIVE

New-onset diabetes after transplantation (NODAT) is a multifactorial, complex metabolic disorder associated with impaired long-term graft function, reduced recipient survival, and increased risks of cardiovascular disease and infectious complications. The impact of NODAT is generally underestimated partly due to the inconsistent criteria that have been previously used for its diagnosis and to the generally short observation periods. The aim of this article was to review the recent literature on NODAT and to highlight the novel implications.

FINDINGS

The 2010 American Diabetes Association guidelines provide useful, simplified criteria to unify the diagnosis including application of hemoglobin A1C levels. We sought to establish the impact of various modifiable and nonmodifiable risk factors. A vast number of papers have examined the effects of immunosuppressive medications on the development of NODAT: Neither calcineurin inhibitor nor sirolimus (SRL) or steroids seems to be innocent of contributing to it. Immunosuppressants account for 74% of the occurrence of NODAT. Among modifiable risk factors, obesity is independent and significant, with great prevalence in the population. In additional to lifestyle modifications, the role of bariatric surgery (BS) either before or after transplantation is highlighted herein as a strategy to reduce disease in the view of the results among overweight, nontransplanted patients.

SUMMARY

Because of the strong association between high glucose values in the early posttransplant period and the development of NODAT, the condition must be recognized early after (or even before) transplantation by intensive screening. Patients at risk for NODAT must modify appropriate risk factors and particularly undergo pretransplant planning and/or posttransplant adjustment individualizing immunosuppressive therapy to mitigate the risk of this serious complication.

Linear growth in pediatric renal transplant recipients receiving sirolimus

SRL is a potent macrolide immunosuppressive agent that can be used as maintenance therapy for prevention of rejection and avoidance of CNI nephrotoxicity. However, animal studies indicate that SRL may inhibit skeletal and muscle growth. We analyzed linear growth in 25 children, age 1-15 yr old, maintained on SRL to determine whether SRL is detrimental to linear growth. Height z-scores at baseline were compared with those at 24 months. We also compared linear growth in children receiving SRL to patients maintained on TAC. Height z-scores over 24 months did not significantly change in the SRL group as a whole. Z-scores improved in 13 of 25 patients (52%). Children with improved z-scores were significantly younger than patents who did not display improved growth: 6 ± 5 yr vs. 11 ± 4 yr (p < 0.05). Height z-scores in SRL and TAC-based patients were no different initially and at 24 months, and a similar number of patients in each group displayed improved height scores. Height z-scores improved in 52% of patients on SRL and occurred predominantly in younger patients for the initial 24 months of treatment. Linear growth in SRL patients was also similar to the results in TAC-based patients. Therefore, our data did not identify a significant adverse effect of SRL on growth.

Tacrolimus and sirolimus induce reproductive abnormalities in female rats

BACKGROUND

Immunosuppression medications contribute to posttransplant diabetes mellitus in patients and can cause insulin resistance in male rats. Tacrolimus (TAC)-sirolimus (SIR) immunosuppression is also associated with appearance of ovarian cysts in transplant patients. Because insulin resistance is observed in patients with polycystic ovary syndrome, we hypothesized that TAC or SIR may induce reproductive abnormalities.

METHODS

We monitored estrus cycles of adult female rats treated daily with TAC, SIR, and combination of TAC-SIR, or diluent (control) for 4 weeks. Animals were then challenged with oral glucose to determine their glucose and insulin responses, killed, and their blood and tissues, including ovaries and uteri harvested.

RESULTS

TAC and TAC-SIR treatments increased mean random glucose concentrations (P<0.05). TAC, SIR, and TAC-SIR treatments also increased the glucose response to oral glucose challenge (P<0.05). The insulin response to glucose was significantly higher in rats treated with SIR compared with TAC (P<0.05). TAC, SIR and TAC-SIR treatments reduced number of estrus cycles (P<0.05). The ovaries were smaller after SIR and TAC-SIR treatment compared with controls. The TAC and TAC-SIR treatment groups had fewer preovulatory follicles. Corpora lutea were present in all groups. Ovarian aromatase expression was reduced in the SIR and TAC-SIR treatment groups. A significant (P<0.05) reduction in uterine size was observed in all treatment groups when compared with controls.

CONCLUSION

In a model of immunosuppressant-induced hyperglycemia, both TAC and SIR induced reproductive abnormalities in adult female rats, likely through different mechanisms.

Rapamycin-induced hypophosphatemia and insulin resistance are associated with mTORC2 activation and Klotho expression

Rapamycin, an immunosuppressive drug used to prevent rejection after kidney transplantation, influences phosphate homeostasis, induces insulin resistance and has been shown to prolong lifespan in animal models. Because Klotho is an aging-suppressor gene controlling phosphate metabolism and insulin sensitivity, we investigated the influence of rapamycin on Klotho expression. A total of 100 kidney transplant recipients, 50 chronically treated with rapamycin and 50 with calcineurin inhibitors, were enrolled; 20 healthy subjects were employed as control. In the rapamycin group, serum phosphate was lower than in the CNI group with an increase in phosphate excretion and a reduction in its reabsorption. In addition, rapamycin increased insulin resistance as shown by HOMA index. Rapamycin treatment of an immortalized proximal tubular cell line induced the expression of Klotho, the phosphorylation of AKT in Ser473, downstream target of mTORC2 and the expression of RICTOR, mTORC2 main component. AKT inhibition reduced the rapamycin-induced expression of Klotho. In vivo rapamycin treatment induced higher degree of RICTOR and AKT Ser(473) expression directly correlating with long-term rapamycin exposure, FE(PO4) and HOMA index. In conclusion, our data would suggest that rapamycin may influence phosphate homeostasis and insulin resistance modulating Klotho expression through mTORC2 activation.

Abdominal aortic aneurysm repair with a functional autotransplanted kidney

During the course of their practice, most urologists will encounter only a few patients with renal autotransplants. Even fewer will encounter those with renal autotransplants requiring abdominal aortic aneurysm (AAA) surgery. Although there is some literature describing AAA surgery in renal allotransplant patients, there is little such literature regarding AAA surgery in patients with autotransplanted kidneys. We present a case of a patient with a single, functioning, autotransplanted kidney who required AAA surgery. We also discuss the issue of the need for renal protection.

Five-year experience using sirolimus-based, calcineurin inhibitor-free immunosuppression in pediatric renal transplantation

From December 2003 to December 2008, we employed a protocol for withdrawing TAC and converting to SRL in a cohort of low-risk renal pediatric transplant recipients. We report our experience in these children with respect to graft survival, AR episodes, renal function, and adverse events. All patients received basiliximab induction and TAC, MMF, and prednisone. Criteria for conversion to SRL included first transplants without histologic evidence for AR on three-month surveillance biopsies. Patient exclusion criteria included AR prior to or before surveillance biopsies, polyoma (BK) virus nephropathy, a history of nephrotic syndrome, or multiple organ transplants. Fifty-one of 137 patients who received transplants from December 2003 to December 2008 met criteria for withdrawal of TAC and were converted to SRL. SRL was discontinued in 11 children because of adverse events within 12 months after conversion. Among the remaining 40 patients, actuarial graft survival was 91% at five yr. AR occurred in 13% of patients within one yr after conversion. Complications from SRL included aphthous ulcers (30%); viremia with BK virus (20%), EBV (13%), and CMV (3%); proteinuria (7%); elevated cholesterol (7%); diabetes mellitus (2%); thrombocytopenia (2%); erectile dysfunction (2%); and lymph edema (2%). SRL was discontinued in 20%, predominantly for aphthous ulcers. Our experience with SRL-based immunosuppression demonstrates that a CNI-free regimen can be successful in lower-risk patients meeting our selection criteria. Aphthous ulcers and BK virus viremia were the most prevalent adverse events.

[Evaluation of patients' readiness for surgery when called from the waiting list for kidney transplantation: experience of the Budapest Centre]

The aim of this study was to assess the impact of the establishment of waiting list committee on recipient evaluation for kidney transplantation. Studies on this issue have not been previously reported.

METHODS

Data of 714 patients were collected between September 1, 2007 and April 20, 2010. Of the 714 patients 354 were transplanted. Data from the first 16 months period were compared to those obtained during the second 16 months period.

RESULTS

During the first period 171 patients (47.9%) were unfit for transplantation [129 patients (36.1%) were refused after telephone information and 42 patients (11.8%) after clinical investigation]. During the second period 141 (39.5%) patients were found to be unsuitable [80 patients (22.4%) after telephone information and 61 patients (17.1)] after clinical examination. During the two periods of the study 44% of patients were unfit for transplantation. A considerable number of patients were refused because of cardiologic reasons. The percent of fit patients was 52.1% in the first period and 60.5% in the second period. In addition, the percent of unfit patients who were unsuitable for kidney transplantation after telephone information decreased from 36.1% to 22.4%, while the percent of unfit patients after clinical evaluation increased from 11.% to 17.1%.

CONCLUSIONS

Authors conclude that waiting list committee made an effective work.

New-onset diabetes mellitus in kidney transplant recipients discharged on steroid-free immunosuppression

BACKGROUND

New-onset diabetes after transplant (NODAT) is a serious complication after kidney transplantation. We studied the relationship between steroid-free maintenance regimens and NODAT in a national cohort of adult kidney transplant patients.

METHODS

A total of 25,837 previously nondiabetic kidney transplant patients, engrafted between January 1, 2004, and December 31, 2006, were included in the study. Logistic regression analysis was used to compare the risk of developing NODAT within 3 years after transplant for patients discharged with and without steroid-containing maintenance immunosuppression regimens. The effect of transplant program-level practice regarding steroid-free regimens on the risk of NODAT was studied as well.

RESULTS

The cumulative incidence of NODAT within 3 years of transplant was 16.2% overall; 17.7% with maintenance steroids and 12.3% without (P<0.001). Patients discharged with steroids had 42% greater odds of developing NODAT compared with those without steroids (adjusted odds ratio [AOR]=1.42, 95% confidence interval [CI]=1.27-1.58, P<0.001). The maintenance regimen of tacrolimus and mycophenolate mofetil or mycophenolate sodium was associated with 25% greater odds of developing NODAT (AOR=1.25, 95% CI=1.08-1.45, P=0.003) than the regimen of cyclosporine and mycophenolate mofetil or mycophenolate sodium. Several induction therapies also were associated with lower odds of NODAT compared with no induction. Patients from programs that used steroid-free regimens for a majority of their patients had reduced odds of NODAT compared with patients from programs discharging almost all of their patients on steroid-containing regimens.

CONCLUSION

The adoption of steroid-free maintenance immunosuppression at discharge from kidney transplantation in selected patients was associated with reduced odds of developing NODAT within 3 years.

New-onset diabetes after transplantation: risk factors and clinical impact

With improvements in patient and graft survival, increasing attention has been placed on complications that contribute to long-term patient morbidity and mortality. New-onset diabetes after transplantation (NODAT) is a common complication of solid-organ transplantation, and is a strong predictor of graft failure and cardiovascular mortality in the transplant population. Risk factors for NODAT in transplant recipients are similar to those in non-transplant patients, but transplant-specific risk factors such as hepatitis C (HCV) infection, corticosteroids and calcineurin inhibitors play a dominant role in NODAT pathogenesis. Management of NODAT is similar to type 2 diabetes management in the general population. However, adjusting the immunosuppressant regimen to improve glucose tolerance must be weighed against the risk of allograft rejection. Lifestyle modification is currently the strategy with the least risk and the most benefit.

Endoscopic application of dextranomer/hyaluronic acid copolymer in the treatment of vesico-ureteric reflux after renal transplantation

OBJECTIVE

• To evaluate the success of endoscopic dextranomer/hyaluronic acid copolymer (DHAC) application in the treatment of patients with recurrent urinary tract infections (UTIs) and vesico-ureteric reflux (VUR) into the transplanted graft after renal transplantation.

PATIENTS AND METHODS

• Between January 2008 and April 2009, 19 patients with recurrent UTIs presented VUR proven by voiding cystourethrography. • To correct VUR of the transplanted ureter, DHAC was injected endoscopically using hydrodistention technique. • Pre- and postoperative serum creatinine levels, the number of pre- and postoperative UTIs, postoperative complications and reflux resolution rate were recorded. The mean follow-up was 6.5 months.

RESULTS

• The average number of UTIs was reduced significantly from 4.89 (range 2-14) to 1.31 (range 0-4) on pre- and postoperative follow-up, respectively, of 6 months (P < 0.001). The success rate increased from 57.9% after the first injection to 78.9% after the second injection. • The remaining four patients with residual VUR received long-term low dose antibiotic prophylaxis. In total, two (10.5%) patients developed increasing creatinine levels postoperatively as a result of distal ureteral obstruction, and temporary urinary drainage was necessary in both patients.

CONCLUSIONS

• DHAC appears to be an efficient and minimal invasive method for treating VUR after renal transplantation with respect to short-term success. • Further investigation with a larger group of patients and longer follow-up is needed to evaluate the prolonged effect, as well as any potential side effects.

Review: metformin: potential benefits and use in chronic kidney disease

Diabetes mellitus is the commonest cause of end-stage renal failure in both Australia and New Zealand. In addition, the burden of diabetes is prominent in those with chronic kidney disease who have not yet reached the requirement for renal replacement therapy. While diabetes is associated with a higher incidence of mortality and morbidity in all populations studied with kidney disease, little is known about optimal treatment strategies for hyperglycaemia and the effects of glycaemic treatment in this large group of patients. Metformin is recommended as the drug of first choice in patients diagnosed with type 2 diabetes in the USA, Europe and Australia. There are potential survival benefits associated with the use of metformin in additional to recent studies suggesting benefits in respect to cardiovascular outcomes and metabolic parameters. The use of metformin has been limited in patients with renal disease because of the perceived risk of lactic acidosis; however, it is likely that use of this drug would be beneficial in many with chronic kidney disease. Thus the potential benefits and harms of metformin are outlined in this review with suggestions for its clinical use in those with kidney disease.

Measurements of serum pituitary-gonadal hormones and investigation of sexual and reproductive functions in kidney transplant recipients

Objective. To investigate changes in serum pituitary-gonadal hormones and restoration of sexual and reproductive functions after successful kidney transplantation. Patients and Methods. Serum pituitary-gonadal hormones before and after kidney transplantation were measured in 78 patients with end-stage renal disease (ESRD) and in 30 healthy adults. Pre- and postoperative semen specimens of 46 male recipients and 15 male controls were collected and compared. Additional 100 married kidney transplant recipients without children were followed up for 3 years to observe their sexual function and fertility. Results. Serum PRL, LH, and T or E₂ levels gradually restored to the normal ranges in all kidney transplant recipients, and sperm density, motility, viability, and morphology significantly improved in the male recipients 4 months after successful kidney transplantation (P < .05). Thirty-three male recipients (55.93%) reobtained normal erectile function, and 49 kidney transplant recipients (61.25%) had children within the 3-year follow-up period. Conclusion. Successful kidney transplantation could effectively improve pituitary-gonadal hormone disturbance and sexual and reproductive dysfunctions of ESRD patients.

Sexual dysfunction in chronic liver disease: is liver transplantation an effective cure?

The goal of liver transplantation is not only to ensure patient long-term survival but also to offer the opportunity to achieve psychologic and physical integrity. Quality of life after liver transplantation may be affected by unsatisfactory sexual function. Before liver transplantation, sexual dysfunction and sex hormone disturbances are reported in men and women mainly due to abnormality of physiology of the hypothalamic-pituitary-gonadal axis and, in some cases, origin of liver disease. Successful liver transplantation should theoretically restore hormonal balance and improve sexual function both in men and women, thus improving the reproductive performance. However, after transplantation, up to 25% of patients report persistent sexual dysfunction, and approximately one third of patients describe the appearance of de novo sexual dysfunction. Despite the described high prevalence of this condition, epidemiologic data are relatively scant. Further studies on pathophysiology and risk factors in the field of sexual function after liver transplantation along with new strategies to support and inform patients on the waiting list and after surgery are needed.

Transplantation in diabetic kidney failure patients: modalities, outcomes, and clinical management

Diabetes mellitus (DM) is a common and devastating disease, affecting up to 19.3 million Americans. It is the leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the United States. Diabetic patients with ESRD have a high incidence of cardiovascular disease and death. For those kidney transplant patients with no history of DM prior to transplantation, the development of new onset diabetes after transplantation (NODAT) also poses a serious threat to both graft and patient survival. Kidney transplantation is the best renal replacement option for diabetic ESRD and has the potential to halt the progression of cardiovascular diseases. Early referral for transplant evaluation is essential for pre-emptive or early kidney transplantation in this cohort of patients. In type 1 DM patients with ESRD, simultaneous pancreas and kidney transplantation (SPK) should be encouraged; and in patients facing prolonged waiting time for SPK transplantation but with an available living donor, living donor kidney transplantation followed by pancreas after kidney transplantation (PAK) is a suitable alternative. Islet transplantation in type 1 diabetics is deemed experimental by Medicare, and easy access to this modality remains restricted to qualified patients enrolled in clinical trials or with private insurance. The optimal management of kidney transplant patients with pre-existent DM or NODAT involves a multi-pronged approach consisting of pharmacological and nonpharmacological intervention to address all potential cardiovascular risk factors such as glycemic and lipid control, blood pressure control, weight loss, and smoking cessation. Finally, re-transplantation should be recommended in suitable kidney transplant patients when the kidney allograft demonstrates continuous and progressive decline in function.

Effect of everolimus on cell viability in nonfunctioning pituitary adenomas

CONTEXT

Pituitary adenomas can cause specific syndromes due to hormone excess and/or determine sellar mass symptoms. Pituitary cell growth can sometimes be influenced by medical therapy, such as for somatotroph adenomas treated with somatostatin analogs or prolactinomas treated with dopaminergic drugs. However, nonfunctioning pituitary adenomas (NFAs) are still orphans of medical therapy. Everolimus (RAD001), a derivative of rapamycin, is a well-known immunosuppressant drug, which has been recently shown to have antineoplastic activity in several human cancers.

OBJECTIVE

The objective of the study was to investigate the possible antiproliferative effects of RAD001 in human NFAs.

DESIGN

We collected 40 NFAs that were dispersed in primary cultures, treated without or with 1 nm to 1 microm RAD001, 10 nm cabergoline, 10 nm SOM230 (a somatostatin receptor multiligand), and/or 50 nm IGF-I. Cell viability and apoptosis were evaluated after 48 h, and vascular endothelial growth factor (VEGF) secretion was assessed after an 8-h incubation. Somatostatin and dopamine subtype 2 receptor expression was investigated by quantitative PCR.

RESULTS

In 28 cultures (70%), Everolimus significantly reduced cell viability (by approximately 40%; P < 0.05 vs. control), promoted apoptosis (+30%; P < 0.05 vs. control), inhibited p70S6K activity (-20%), and blocked IGF-I proliferative and antiapoptotic effects. In selected tissues cotreatment with SOM230, but not cabergoline, exerted an additive effect. Everolimus did not affect VEGF secretion but blocked the stimulatory effects of IGF-I on this parameter.

CONCLUSIONS

Everolimus reduced NFA cell viability by inducing apoptosis, with a mechanism likely involving IGF-I signaling but not VEGF secretion, suggesting that it might represent a possible medical treatment of invasive/recurrent NFAs.