Patient survival and cardiovascular risk after kidney transplantation: the challenge of diabetes

Significant racial differences in the key factors associated with early graft loss in kidney transplant recipients

BACKGROUND

There is continued and significant debate regarding the salient etiologies associated with graft loss and racial disparities in kidney transplant recipients.

METHODS

This was a longitudinal cohort study of all adult kidney transplant recipients, comparing patients with early graft loss (<5 years) to those with graft longevity (surviving graft with at least 5 years of follow-up) across racial cohorts [African-American (AA) and non-AA] to discern risk factors.

RESULTS

524 patients were included, 55% AA, 151 with early graft loss (29%) and 373 with graft longevity (71%). Consistent within both races, early graft loss was significantly associated with disability income [adjusted odds ratio (AOR) 2.2, 95% CI 1.1-4.5], Kidney Donor Risk Index (AOR 3.2, 1.4-7.5), rehospitalization (AOR 2.1, 1.0-4.4) and acute rejection (AOR 4.4, 1.7-11.6). Unique risk factors in AAs included Medicare-only insurance (AOR 8.0, 2.3-28) and BK infection (AOR 5.6, 1.3-25). Unique protective factors in AAs included cardiovascular risk factor control: AAs with a mean systolic blood pressure <150 mm Hg had 80% lower risk of early graft loss (AOR 0.2, 0.1-0.7), while low-density lipoprotein <100 mg/dl (AOR 0.4, 0.2-0.8), triglycerides <150 mg/dl (AOR 0.4, 0.2-1.0) and hemoglobin A1C <7% (AOR 0.2, 0.1-0.6) were also protective against early graft loss in AA, but not in non-AA recipients.

CONCLUSIONS

AA recipients have a number of unique risk factors for early graft loss, suggesting that controlling cardiovascular comorbidities may be an important mechanism to reduce racial disparities in kidney transplantation.

Transplant options for patients with type 2 diabetes and chronic kidney disease

Chronic kidney disease (CKD) has become a real epidemic around the world, mainly due to ageing and diabetic nephropathy. Although diabetic nephropathy due to type 1 diabetes mellitus (T1DM) has been studied more extensively, the vast majority of the diabetic CKD patients suffer from type 2 diabetes mellitus (T2DM). Renal transplantation has been established as a first line treatment for diabetic nephropathy unless there are major contraindications and provides not only a better quality of life, but also a significant survival advantage over dialysis. However, T2DM patients are less likely to be referred for renal transplantation as they are usually older, obese and present significant comorbidities. As pre-emptive renal transplantation presents a clear survival advantage over dialysis, all T2DM patients with CKD should be referred for early evaluation by a transplant center. The transplant center should have enough time in order to examine their eligibility focusing on special issues related with diabetic nephropathy and explore the best options for each patient. Living donor kidney transplantation should always be considered as the first line treatment. Otherwise, the patient should be listed for deceased donor kidney transplantation. Recent progress in transplantation medicine has improved the "transplant menu" for T2DM patients with diabetic nephropathy and there is an ongoing discussion about the place of simultaneous pancreas kidney (SPK) transplantation in well selected patients. The initial hesitations about the different pathophysiology of T2DM have been forgotten due to the almost similar short- and long-term results with T1DM patients. However, there is still a long way and a lot of ethical and logistical issues before establishing SPK transplantation as an ordinary treatment for T2DM patients. In addition recent advances in bariatric surgery may offer new options for severely obese T2DM patients with CKD. Nevertheless, the existing data for T2DM patients with advanced CKD are rather scarce and bariatric surgery should not be considered as a cure for diabetic nephropathy, but only as a bridge for renal transplantation.

Single-nucleotide polymorphisms in P450 oxidoreductase and peroxisome proliferator-activated receptor-α are associated with the development of new-onset diabetes after transplantation in kidney transplant recipients treated with tacrolimus

BACKGROUND

New-onset diabetes after transplantation (NODAT) is an important complication after kidney transplantation. The etiology of the malady is multifactorial and includes both environmental and genetic factors. NODAT is a polygenic disease and many single-nucleotide polymorphisms could constitute potential risk factors. Peroxisome proliferator-activated receptor α (PPARα) and P450 oxidoreductase (POR) play a central role in the control of energy metabolism in humans. Some recent data highlighted a possible functional impact of two single-nucleotide polymorphisms in PPARα (rs4253728 G>A and rs4823613 A>G) and one coding variant in POR (rs1057868; POR*28; A503V) on the activity of their respective encoded proteins. In the present study, we assessed the association between these variants and the risk of developing NODAT after kidney transplantation.

METHODS

Development of NODAT was investigated in 101 renal transplant recipients receiving tacrolimus-based immunosuppressive therapy. Patients were genotyped for PPARα and POR. The incidence of NODAT was compared between different genotypes. Kaplan-Meier and Cox's proportional-hazard analysis were used to evaluate the association of NODAT with potential risk factors. Potential nongenetic risk factors were also considered.

RESULTS

The PPARα rs4253728A>G and POR*28 variant alleles were both independently associated with an increased risk for NODAT with respective odds ratios of 8.6 [95% confidence interval (CI)=1.4-54.2; P=0.02] and 8.1 (95% CI=1.1-58.3; P=0.04). Other risk predictors included sex and body weight.

CONCLUSION

This candidate-gene study shows that polymorphisms in PPARα and POR might predispose patients being treated with tacrolimus to the development of NODAT after kidney transplantation. Patient management after organ transplantation might benefit from genotype data.

Cardiac response to early conversion from calcineurin inhibitor to everolimus in renal transplant recipients: an echocardiographic substudy of the randomized controlled CENTRAL trial

BACKGROUND

Calcineurin inhibitors are associated with adverse cardiac effects. Mammalian target of rapamycin inhibitors have been reported to have beneficial effects on cardiac function. We used advanced echocardiographic techniques in a randomized controlled trial to examine cardiac responses to an everolimus-based arm versus a calcineurin inhibitor-based arm in de novo kidney transplant recipients.

METHODS

This was a substudy of the Certican Nordic Trial in Renal Transplantation study, a randomized controlled trial on safety and efficacy of early (week 7 after renal transplantation) conversion from cyclosporine A (CsA) to everolimus versus continued CsA during 1-year follow-up. A total of 44 patients (66% men; median [range] age, 61 [28-78] years) were included. All participants had a complete echocardiographic evaluation at baseline and at 1-year follow-up.

RESULTS

Left ventricular (LV) systolic function, LV mass, left atrial volumes, and blood pressure response did not differ between groups during 1-year follow-up. There was, however, a difference between the groups in change in peak early mitral velocity after 1 year (P=0.02), and E/e' ratio trended higher in the everolimus group (P=0.09).

CONCLUSIONS

Early conversion from CsA-based to everolimus-based immunosuppressive treatment in de novo renal transplant recipients caused marginal changes in LV diastolic function but no effect on LV systolic function or LV mass.

Cardiovascular death in kidney recipients treated with renin-angiotensin system blockers

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) are widely prescribed after kidney transplantation, but evidence for an improvement in outcomes is mixed. A recent trial demonstrated a significantly lower incidence of major cardiovascular events in ACEI-treated recipients.

METHODS

Collaborative Transplant Study data on cardiovascular death during years 2 to 10 after kidney transplantation in patients with a functioning graft were analyzed according to whether ACEI/ARB or other antihypertensive therapy (excluding diuretics) was administered at year 1.

RESULTS

Of 39,251 transplants analyzed, 15,250 (38.9%) received ACEI/ARB and 24,001 (61.1%) received other antihypertensive therapy at year 1 after transplantation. The mean duration of follow-up was 5.8 years. During years 2 to 10 after transplantation, cardiovascular death occurred in 918 patients (cumulative incidence=4.7%) with a functioning graft. The rate of cardiovascular death was similar in patients who received ACEI/ARB therapy or other antihypertensive treatment overall and in subpopulations of patients who were considered by the transplant center to be at an increased cardiovascular risk, had no pretransplant risk factors, were aged 60 years and older, were treated for diabetes at year 1, or had serum creatinine of 130 μmol/L or higher at year 1. Multivariable Cox regression analysis confirmed that treatment with ACEI/ARB did not confer a beneficial effect beyond that conferred by other antihypertensive treatments on the cumulative incidence of cardiovascular death during years 2 to 10 (hazard ratio=1.1, P=0.24).

CONCLUSIONS

This large-scale retrospective analysis of prospectively collected data shows that the rate of cardiovascular death in kidney transplant recipients receiving ACEI/ARB or other antihypertensive medications is virtually identical.

Pancreas transplantation: solid organ and islet

Transplantation of the pancreas, either as a solid organ or as isolated islets of Langerhans, is indicated in a small proportion of patients with insulin-dependent diabetes in whom severe complications develop, particularly severe glycemic instability and progressive secondary complications (usually renal failure). The potential to reverse diabetes has to be balanced against the morbidity of long-term immunosuppression. For a patient with renal failure, the treatment of choice is often a simultaneous transplant of the pancreas and kidney (SPK), whereas for a patient with glycemic instability, specifically hypoglycemic unawareness, the choice between a solid organ and an islet transplant has to be individual to the patient. Results of SPK transplantation are comparable to other solid-organ transplants (kidney, liver, heart) and there is evidence of improved quality of life and life expectancy, but the results of solitary pancreas transplantation and islets are inferior with respect to graft survival. There is some evidence of benefit with respect to the progression of secondary diabetic complications in patients with functioning transplants for several years.

Expanding the use of expanded criteria donors in kidney transplantation

PURPOSE

Although the use of kidney allografts from expanded criteria donors (ECD) has increased in recent years, the reported discard rates are also growing. The influence of ECD characteristics on transplant outcomes is still underevaluated.

METHODS

This retrospective study investigated the influence of preimplantation biopsy findings and delayed graft function (DGF) on patient and graft survivals and renal function at 36 months in a cohort of 372 ECD kidney transplant recipients.

RESULTS

Patient and graft survivals were 91.6 and 68.9 %. The incidence of biopsy-proven acute rejection was 31 %. There were no differences in patient (88.6 vs. 91.1 vs. 94.7 vs. 78.6 %, p = 0.10) or graft (78.1 vs. 72.2 vs. 60.5 vs. 62.6 %, p = 0.14) survivals and renal function (41.7 ± 25.6 vs. 39.9 ± 29.9 vs. 38.1 ± 30.6 vs. 37.4 ± 29.2 mL/min, p = 0.79) comparing ECD kidneys with mild, moderate, and severe histological changes or with no preimplantation biopsy, respectively. However, severe scored transplants had the worst death-censored graft survival (OR 3.1, 95 % CI 1.4-6.9, p = 0.007). No significant differences in patient (86.2 vs. 83.4 %, p = 0.17) or graft (73.7 vs. 65.9 %, p = 0.06) survivals and renal function (38.9 ± 28.6 vs. 39.9 ± 28.4 mL/min, p = 0.72) were observed comparing patients with or without DGF. Multivariable analysis found diabetes history as the only independent risk factor for graft loss (OR 2.1, 95 % CI 1.3-3.3, p = 0.003) or patient death (OR 3.1, 95 % CI 1.5-5.8, p < 0.001).

CONCLUSIONS

Within the limitations of sample size and short follow-up time, in this cohort of ECD kidney transplant recipients the severity of histological changes observed in preimplantation biopsies was independently associated with graft loss.

Strategies for the management of adverse events associated with mTOR inhibitors

Mammalian target of rapamycin (mTOR) inhibitors are used as potent immunosuppressive agents in solid-organ transplant recipients (everolimus and sirolimus) and as antineoplastic therapies for various cancers (eg, advanced renal cell carcinoma; everolimus, temsirolimus, ridaforolimus). Relevant literature, obtained from specific PubMed searches, was reviewed to evaluate the incidence and mechanistic features of specific adverse events (AEs) associated with mTOR inhibitor treatment, and to present strategies to effectively manage these events. The AEs examined in this review include stomatitis and other cutaneous AEs, wound-healing complications (eg, lymphocele, incisional hernia), diabetes/hyperglycemia, dyslipidemia, proteinuria, nephrotoxicity, delayed graft function, pneumonitis, anemia, hypertension, gonadal dysfunction, and ovarian toxicity. Strategies for selecting appropriate patients for mTOR inhibitor therapy and minimizing the risks of AEs are discussed, along with best practices for identifying and managing side effects. mTOR inhibitors are promising therapeutic options in immunosuppression and oncology; most AEs can be effectively detected and managed or reversed with careful monitoring and appropriate interventions.

Lower magnesium level associated with new-onset diabetes and pre-diabetes after kidney transplantation

BACKGROUND

Hypomagnesemia is associated with increased peripheral insulin resistance in the general population. It is frequently seen after renal transplantation. We examined its role as a risk factor for new-onset diabetes after transplantation (NODAT) and new-onset pre-diabetes after transplantation (NOPDAT).

METHODS

A retrospective analysis of 138 previously non-diabetic renal transplant recipients was conducted. Cox and logistic regression analyses were performed to examine the associations between 1-month post-transplant serum magnesium level and subsequent diagnoses of NODAT/NOPDAT.

RESULTS

NODAT was diagnosed in 34 (24.6 %) and NOPDAT in 12 (8.7 %) patients. Median time to diagnosis of NODAT/NOPDAT was 20.4 months (interquartile range [IQR] 6.8-34.8). Median follow up for the entire group was 3.5 years (IQR 2.3-5.6). Mean magnesium level at 1 month after transplantation was significantly lower in patients subsequently diagnosed with NODAT/NOPDAT (1.60 ± 0.27 vs. 1.76 ± 0.29 mg/dl, p = 0.002). Cox regression analysis identified a trend towards developing NODAT/NOPDAT with lower baseline magnesium levels (hazard ratio 0.89 per 0.1 mg/dl increment in magnesium level, 95 % confidence interval [CI] = 0.78-1.01, p = 0.07); a stronger relationship between the two variables was seen at logistic regression analysis (odds ratio 0.81 per 0.1 mg/dl increment in serum magnesium (95 % CI 0.67-0.98, p = 0.03).

CONCLUSIONS

A lower magnesium level at 1 month after transplantation may be predictive of a subsequent diagnosis of glucose intolerance or diabetes in renal transplant recipients. Whether replenishing magnesium stores can prevent development of these disorders requires further investigation.

Morbid obesity is not an independent predictor of graft failure or patient mortality after kidney transplantation

OBJECTIVE

Obesity is often an absolute contraindication to kidney transplant, but an internal analysis of our center's recipients suggests that not all obese populations exhibit poor outcomes. We used national data to compare outcomes in select groups of morbidly obese and normal-weight recipients after kidney transplant.

DESIGN

This study was a retrospective analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database.

SUBJECTS

The study sample consisted of 30,132 morbidly obese (body mass index [BMI] 35-40 kg/m(2)) and normal-weight (BMI 18.5-24.9 kg/m(2)) patients who underwent primary kidney-only transplantation between 2001 and 2006.

MAIN OUTCOME MEASURE

Crude 3-year graft and patient survival rates of morbidly obese and normal-weight subgroups were evaluated. Logistic regression modeling compared 3-year graft failure and patient mortality in morbidly obese and normal-weight subgroups with opposite characteristics. Kaplan-Meier survival curves were created for 3-year graft and patient survival. Cox proportional hazard regression modeling was used to determine hazards for patient and graft mortality.

RESULTS

No differences in crude graft and patient survival rates were seen between normal weight and morbidly obese recipients who were African American, diabetic, and 50 to 80 years of age. Morbidly obese recipients who were nondialysis dependent, nondiabetic, had good functional status, and received living-donor transplants had significantly lower 3-year graft failure and patient mortality risk compared with normal-weight recipients who were dialysis dependent, diabetic, had poor functional status, and received a deceased-donor transplant, respectively (P < .01). Morbidly obese recipients have significantly lower graft and patient survival curves compared with normal-weight recipients; however, multivariate regression analysis reveals that morbid obesity is not an independent predictor of graft failure or patient mortality.

CONCLUSIONS

Morbid obesity is not independently associated with graft failure or patient mortality; therefore, it should not be used as a contraindication to kidney transplantation.

Glutathione S-transferase M1 gene polymorphism is associated with susceptibility to impaired long-term allograft outcomes in renal transplant recipients

BACKGROUND

Despite improved post-transplantation care, progress in long-term kidney allograft survival of diabetic renal transplant recipients (pre-DM RTR) is worse than that of non-diabetic recipients (non-DM). We hypothesized that there are other potential risk factors, that predispose RTR to adverse renal allograft outcomes.

METHODS

A total of 323 transplant recipients who underwent renal transplantation between March 2000 and January 2008 were recruited. The composite end-point consisted of serum creatinine (SCr) doubling, graft failure, and death. Baseline clinical data were recorded, and polymerase chain reaction-restriction fragment length polymorphism measurements of interleukin (IL)-4, IL-10, IL-23, glutathione S-transferase (GST)A1, GSTM1, and GSTP1 polymorphisms were determined. The risk factors for developing the primary outcome were analyzed among these clinical and genetic factors.

RESULTS

Within a mean follow-up of 71.1 ± 24 months, there were 43 (13.3 %) patients with the primary outcome. Stepwise multivariate Cox regression analysis was used to determine the risk factors for the primary outcome of RTR. Renal transplant recipients who possessed the GSTM1 null genotype had a 2.2-fold risk (95 % CI: 1.10-4.40; P = 0.026) of developing the primary outcome. Additionally, RTR that had DM before transplantation (aHR: 3.31; 95 % CI: 1.77-6.20; P = 0.0002) or changes in SCr 6 to 12 months after transplantation (aHR: 2.83; 95 % CI: 1.29-6.19; P = 0.0095) had an increased risk of developing the primary outcome.

CONCLUSIONS

In addition to the adverse role played by DM, the GSTM1 null genotype also has an unfavorable influence on the long-term allograft outcome of RTR.

Pre-existing diabetes significantly increases the risk of graft failure and mortality following renal transplantation

The aim of this study was to examine the impact of pre-existing diabetes mellitus (DM) on acute rejection, graft loss, and mortality following kidney transplant and whether glycemic control or cardiovascular disease (CVD) risk control with medications influenced outcomes. This was a cohort study of 1002 renal transplants conducted between 2000 and 2008. Patients were included if they received a kidney transplant within the allotted time and were at least 18 yr of age. Cox regression was used to assess acute rejection, graft failure, or death controlling for relevant sociodemographic, clinical, and post-transplant variables. Five-yr patient survival (83% vs. 93%, p < 0.001) and graft survival (74% vs. 79%, p = 0.005) were significantly lower in patients with pre-existing DM. Sequential Cox regression models demonstrated that pre-existing DM was consistently associated with a higher risk of death (HR 2.3-3.0, p < 0.01) and graft failure (HR 1.5-1.8, p < 0.04) in all models except after adjusting for CVD medication use (HR 1.9, p = 0.174 and HR 1.5, p = 0.210, respectively). These data suggest pre-existing DM is a significant risk factor for graft failure and death following renal transplantation and aggressive CVD risk reduction with medications may be an important strategy to reduce mortality and graft failure.

Cardiac troponin T before and after kidney transplantation: determinants and implications for posttransplant survival

Pretransplant cardiac troponin T(cTnT(pre) ) is a significant predictor of survival postkidney transplantation. We assessed correlates of cTnT levels pre- and posttransplantation and their relationship with recipient survival. A total of 1206 adult recipients of kidney grafts between 2000 and 2010 were included. Pretransplant cTnT was elevated (≥0.01 ng/mL) in 56.4%. Higher cTnT(pre) was associated with increased risk of posttransplant death/cardiac events independent of cardiovascular risk factors. Elevated cTnT(pre) declined rapidly posttransplant and was normal in 75% of recipients at 3 weeks and 88.6% at 1 year. Elevated posttransplant cTnT was associated with reduced patient survival (cTnT(3wks) : HR = 5.575, CI 3.207-9.692, p < 0.0001; cTnT(1year) : 3.664, 2.129-6.305, p < 0.0001) independent of age, diabetes, pretransplant dialysis, heart disease and allograft function. Negative/positive predictive values for high cTnT(3wks) were 91.4%/50% respectively. Normalization of cTnT posttransplant was associated with reduced risk. Variables related to elevated cTnT posttransplant included pretransplant diabetes, older age, time on dialysis, high cTnT(pre) and lower graft function. Patients with delayed graft function and those with GFR < 30 mL/min at 3 weeks were more likely to have an elevated cTnT(3wks) and remained at high risk. When allografts restore sufficient kidney function cTnT normalizes and patient survival improves. Lack of normalization of cTnT posttransplant identifies a group of individuals with high risk of death/cardiac events.

The impact of cardiovascular disease and risk factor treatment on ethnic disparities in kidney transplant

There is limited data on the use of cardiovascular disease (CVD) risk factor medications following renal transplant, especially when comparing use across ethnicities. The aim of this study was to compare the incidence, treatment, and impact of CVD between ethnicities in kidney transplant recipients. This was a retrospective cohort study of adults who underwent transplant between 2000 and 2008 within our academic medical transplant center. Pediatrics, multiorgan transplants, and those lost to follow-up were excluded. Data collection included all transplant and sociodemographic characteristics, medication use, CVD risk factor management, and follow-up events, including acute rejection, graft loss, and death. A total of 987 patients were included and followed for a mean of 6.7 ± 3.0 years. The baseline demographics revealed black patients were equally likely to have preexisting CVD (24% vs 25%, P = .651), but more likely to have preexisting diabetes (35% vs 23%, P < .001) or hypertension (97% vs 94%, P = .029). Black patients had poorer treatment of CVD risk factors, with lower rates of control of diabetes (35% vs 51%, P < .05) and dyslipidemia (37% vs 42%, P < .05). Black renal transplant recipients who had preexisting CVD had reduced graft survival rates compared to white patients (10-year rate 50% vs 60%, P = .033), but similar rates of graft survival were found in those without CVD (10-year rate 70% vs 71% in white patients, P = .483). CVD is common in transplant recipients, with black patients having higher rates and poorer control of diabetes and dyslipidemia.

Diabetes and kidney transplantation: past, present, and future

Diabetes mellitus is the most common etiology for end stage renal disease (ESRD) worldwide and in the United States. The incidence of morbidity and mortality is higher in diabetic patients with ESRD due to increased cardiovascular events. Patients with type 2 diabetes who receive a renal allograft have a higher survival rate compared with patients who are maintained on chronic hemodialysis therapy, but there is scarcity of data on long-term graft outcomes. Most recently the development of new onset diabetes after transplantation (NODAT) poses a serious threat to patient and allograft survival. Pre-emptive transplantation and the use of living donors have improved overall survival. In addition, critical management of glucose, blood pressure, and cholesterol are some of the factors that can help minimize adverse outcomes in both patients with pre-existing diabetes and patients who develop NODAT. Future clinical trials are warranted to improve therapeutic medical management of these patients thus influencing graft attrition.

New onset diabetes after kidney transplantation in autosomal dominant polycystic kidney disease: a retrospective cohort study

BACKGROUND

New onset diabetes after transplantation (NODAT) is a common adverse outcome of organ transplantation that increases the risk of cardiovascular disease, infection and graft rejection. In kidney transplantation, apart from traditional risk factors, autosomal dominant polycystic kidney disease (ADPKD) has also been reported by several authors as a predisposing factor to the development of NODAT, but any rationale for an association between ADPKD and NODAT is unclear. We examined the cumulative incidence of NODAT in or own transplant population comparing ADPKD patients with non-ADPKD controls.

METHODS

A retrospective cohort study to determine the cumulative incidence of patients developing NODAT (defined by World Health Organization-based criteria and/or use of hypoglycaemic medication) was conducted in 79 patients with ADPKD (79 transplants) and 423 non-ADPKD controls (426 transplants) selected from 613 sequential transplant recipients over 8 years. Patients with pre-existing diabetes as a primary disease or comorbidity and/or with minimal follow up or early graft loss/death were excluded.

RESULTS

Of the 502 patients (505 transplants) studied, 86 (17.0%) developed NODAT. There was no significant difference in the cumulative incidence of NODAT in the ADPKD (16.5%; CI 13.6-20.7%) compared with the non-ADPKD (17.1%; CI 8.3-24.6%) control group. Of the 13 patients in the ADPKD group with NODAT, three required treatment with insulin with or without oral hypoglycaemic agents. Among the 73 NODAT patients in the non-ADPKD group, eight received insulin with or without oral hypoglycaemics. Furthermore, of the patients that did develop NODAT, there was no difference in the time to its development in patients with and without ADPKD.

CONCLUSION

There was no evidence of an increased incidence of NODAT in ADPKD kidney transplant recipients.

Complications and characteristics of patients referred to a joint diabetes renal clinic in Ireland

BACKGROUND AND METHODS

Joint diabetes renal (JDR) clinics are recommended as the appropriate model of care to manage advanced diabetic-associated renal failure. We performed a retrospective review of clinical data and records of the first 60 patients who attended our service and their follow-up at 12 months.

RESULTS

Of the patients, 88 % had type 2 diabetes. At the first visit, 43 % had retinopathy, 56 % had neuropathy, 48 % had overt cardiovascular disease, 13 % had a previous history of stroke and 36 % peripheral arterial disease. Ten percent had lower limb amputation and 33 % had never previously seen a diabetologist. Fifteen percent were still on metformin despite significant renal impairment, while 43 % were on three or more different antihypertensives. Sixty-eight percent were either on an ACE inhibitor or angiotensin receptor blocker. At 12 months, a trend towards a reduction in HbA1c (7.6 ± 2.0 vs. 7.0 ± 1.6 %, p = 0.14) and systolic (159.4 ± 30.8 vs. 141.8 ± 35.5 mmHg, p = 0.13) and diastolic blood pressure (73.2 ± 9.3 vs. 69.2 ± 9.4 mmHg, p = 0.075) was observed. No significant differences were found in the lipid profile or creatinine clearance within the group.

CONCLUSION

Thirty-three percent of patients with advanced diabetic nephropathy had never previously seen a diabetes consultant and a significant proportion had other diabetes-related complications. Patients with diabetic nephropathy may therefore benefit from having a multidisciplinary input at a joint diabetes renal clinic.

New-onset diabetes after kidney transplantation-changes and challenges

Despite substantial improvement in short-term results after kidney transplantation, increases in long-term graft survival have been modest. A significant impediment has been the morbidity and mortality attributable to cardiovascular disease (CVD). New-onset diabetes after transplantation (NODAT) is an independent predictor of cardiovascular events. This review examines recent literature surrounding diagnosis, outcomes and management of NODAT. Amongst otherwise heterogeneous studies, a common finding is the relative insensitivity of fasting blood glucose (FBG) as a screening test. Incorporating self-testing of afternoon capillary BG and glycohemoglobin (HbA(1c) ) detects many cases that would otherwise remain undetected without the oral glucose tolerance test (OGTT). Assessing the impact of NODAT on patient and graft survival is complicated by changes to diagnostic criteria, evolution of immunosuppressive regimens and increasing attention to cardiovascular risk management. Although recent studies reinforce a link between NODAT and death with a functioning graft (DWFG), there seems to be little effect on death-censored graft loss. The significance of glycemic control and diabetes resolution for patient outcomes remain notably absent from NODAT literature and treatment is also a neglected area. This review examines new and old therapeutic options, emphasizing the need to assess β-cell pathology in customizing therapy. Finally, areas warranting further research are considered.

Outcome of deceased donor renal transplantation in diabetic nephropathy: a single-center experience from a developing country

BACKGROUND

Type 2 diabetes mellitus (DM) is the commonest cause of end-stage renal disease (ESRD) worldwide. Renal transplantation (RTx) is the best therapeutic modality for such patients. First-degree relatives of patients with type 2 DM have high risk of diabetes/pre-diabetes. Parents are often too old to be suitable donors, and siblings/children/spouse are either not suitable/acceptable or do not come forward for organ donation. This leaves deceased donation (DD) as only suitable donors. Data scarcity on DDRTx outcome in diabetic nephropathy (DN) prompted us to review our experience. This retrospective single-center 10-year study was undertaken to evaluate patient/graft survival, graft function, rejection episodes, and mortality in these patients.

MATERIALS AND METHODS

Between January 2001 and March 2011, thirty-five DN-ESRD patients underwent DDRTx in our center following cardiac fitness assessment of recipients. All patients received single-dose rabbit-anti-thymocyte globulin for induction and steroids, calcineurin inhibitor, and mycophenolate mofetil/azathioprine for maintenance immunosuppression. Mean recipient age was 49.66 ± 6.76 years, and 25 were men. Mean donor age was 50 ± 16.45 years, 23 were men.

RESULTS

Over a mean follow-up of 2.28 ± 2.59 years, patient and graft survival rates were 68.5% and 88.5%, respectively, with mean SCr of 1.9 ± 0.62 mg/dl. Delayed graft function was observed in 34.3% patients, and 25.7% had biopsy-proven acute rejection; 31.5% patients died, mainly because of infections (22.8%), coronary artery disease (2.86%), and cerebrovascular events (5.7%).

CONCLUSION

DDRTx in patients with DN has acceptable graft function and patient/graft survival over 10-year follow-up in our center and, therefore, we believe it should be encouraged.

Belatacept-versus cyclosporine-based immunosuppression in renal transplant recipients with pre-existing diabetes

BACKGROUND AND OBJECTIVES

Renal transplant recipients with pre-existing diabetes (PD) have reduced graft survival and increased risk of mortality and ischemic heart disease compared with nondiabetic transplant recipients. To assess the effect of belatacept in this high-risk group, we evaluated outcomes of the subpopulation with PD from previously published BENEFIT and BENEFIT-EXT trials.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A post hoc analysis evaluated pooled data from BENEFIT (living donors or standard criteria donors) and BENEFIT-EXT (extended criteria donors). Patients were randomized to receive cyclosporine or a more intensive (MI) or less intensive (LI) belatacept regimen.

RESULTS

Of 1209 intent-to-treat patients, 336 had PD. At 12 months, the belatacept LI arm demonstrated a numerically higher rate of patients surviving with a functioning graft (90.4% MI [103 of 114], 92.8% LI [90 of 97], and 80.8% cyclosporine [101 of 125]), and fewer serious adverse events than cyclosporine or MI patients. Three cases of posttransplant lymphoproliferative disorder were reported in LI patients, one involving the central nervous system. Higher rates (% [95% confidence interval]: 22.8% MI [15.1 to 30.5]; 20.6% LI [12.6 to 28.7]; 14.4% cyclosporine (8.2 to 20.6]) and grades of acute rejection were observed with belatacept. Measured GFR (ml/min per 1.73 m(2), 59.8 MI; 62.5 LI; 45.4 cyclosporine), and cardiovascular risk profile were better for belatacept versus cyclosporine.

CONCLUSIONS

In post hoc analysis of patients with PD, patient/graft survival and renal function at 12 months were numerically higher with belatacept versus cyclosporine, but not statistically significant. Further study is necessary to confirm the benefits belatacept may provide in these patients.

Diabetes and the kidney in pregnancy

The prevalence of diabetes in pregnant women is increasing, with 4% of deliveries in the United States occurring in women with pregestational or gestational diabetes. The proteinuria of late pregnancy is exaggerated in women with diabetes. However, diabetic women with preserved renal function before pregnancy appear to have little risk of deterioration of kidney function during pregnancy. Women with impaired renal function before pregnancy may be at risk for permanent decline of renal function during pregnancy, although it is unclear whether this represents the effect of pregnancy or the natural history of their diabetic renal disease. Preeclampsia, which is more common in women with diabetes, may be difficult to diagnose in this group of women. From the currently available literature, there appears to be no negative effect of pregnancy on the long-term progression of diabetic renal disease if renal function is normal and marked proteinuria is absent, but in light of recent findings in which preeclampsia appears to be associated with an increased risk of end-stage renal disease, large cohort studies will be necessary before this question can be definitively answered.

Outcome of renal transplantation in patients with diabetic nephropathy -- a single-center experience

BACKGROUND

Type 2 diabetes mellitus (DM) is the commonest cause of end-stage renal disease (ESRD) worldwide. Data scarcity on renal transplantation (RTx) outcome in diabetic nephropathy (DN) prompted us to review our experience. This retrospective single-center, 5-year study was undertaken to evaluate patient and graft survival and function, evaluated by serum creatinine (SCr), rejection episodes, and mortality in patients.

PATIENTS AND METHODS

One hundred type 2 DM-ESRD patients underwent RTx [80 living-related (LRD), 20 deceased donor (DD)] at our center following cardiac fitness of recipient. Post-transplant immunosuppression consisted of calcineurin inhibitor-based regimen. The mean donor age in the LRD group was 40.6 years and 52 years in the DD group. Male recipients constituted 95% in the LRD and 65% in the DD group.

RESULTS

Over a mean follow-up of 2.47 years, 1- and 5-year patient/graft survival in LRDRTx was 85.1%/95.9% and 82.6%/95.9%, respectively, and mean SCr (in mg/dl) at 1 and 5 years was 1.38 and 1.58 mg/dl, respectively, with 20% of cases developing acute rejection (AR) episodes. Fifteen percent of patients died, mainly due to infections, and 1.3% died of coronary artery disease (CAD). In DDRTx, over a mean follow-up of 3.17 years, 1- and 4-year patient/graft survival was 72%/89.7% and 54%/89.7%, respectively; mean SCr at 1 and 4 years was 1.40 and 1.75 mg/dl, respectively, with 20% of cases developing AR episodes. Totally, 30% of patients were lost, mainly due to infections, and 10% of patients died from cerebrovascular events.

CONCLUSION

In our center, in patients with RTx for type 2 DM diabetic nephropathy, the 4- and 5-year patient and graft survival rates and graft function can be considered acceptable. The results are better in LRDRTx than in DDRTx patients.

ENPP1/PC-1 K121Q and other predictors of posttransplant diabetes

Diabetes mellitus is a major cause of morbidity and mortality among transplanted patients. This study evaluated the role of the ENPP1 K121Q polymorphism and other variables known to affect diabetes risk in 115 nondiabetic and unrelated patients who underwent kidney transplant at our institution and had consented for use of genetic material (30% whites, 48% blacks, and 22% Hispanics). Thirty-six of these patients (30%) developed posttransplant diabetes mellitus (PTDM) within 1 year of observation from transplant. Black race, ENPP1 K121Q polymorphism, age, body mass index (BMI), and immunosuppressive medications were found to have the strongest associations with PTDM in the logistic regression and receiver operator characteristic (ROC) analysis. However, because ENPP1 K121Q is more common in Hispanics and in blacks, who also have higher PTDM prevalence, the studied genetic polymorphism did not exert independent predictive effect, whereas ethnicity, specifically black versus non-black, was the most robust predictor of PTDM. The model with the largest ROC area under the curve (AUC) of 0.80 was comprised of black/non-black, age, BMI, and tacrolimus treatment as significant predictors. A reduced model containing only ethnicity (black/non-black) and age as predictors yielded similar results (ROC AUC 0.78). We conclude that black race and age are major and not modifiable risk factors for PTDM. The specific role of ENPP1 K121Q on ethnic susceptibility to PTDM deserves further investigation in larger cohorts of transplanted patients.

Associations of pretransplant diabetes mellitus, new-onset diabetes after transplant, and acute rejection with transplant outcomes: an analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database

BACKGROUND

Diabetes and acute rejection are major contributors to morbidity and mortality in kidney transplant recipients. Immunosuppressive medications decrease acute rejection, but increase the frequency of new-onset diabetes after transplant. Our objective was to investigate the joint associations of diabetes (pretransplant diabetes and new-onset diabetes after transplant) and acute rejection with transplant outcomes in a recent transplant cohort.

STUDY DESIGN

Historical cohort study.

SETTING & PARTICIPANTS

37,448 recipients (age ≥ 18 years; 2004-2007) surviving with a functioning transplant for longer than 1 year were identified in the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database as of May 22, 2009.

PREDICTORS

Recipients were stratified into 6 mutually exclusive groups according to status of diabetes and acute rejection at 1 year: group 1, neither (reference; n = 20,964); group 2, new-onset diabetes alone (n = 2,140); group 3, pretransplant diabetes alone (n = 10,730); group 4, acute rejection alone (n = 2,282); group 5, new-onset diabetes and acute rejection (n = 361); and group 6, pretransplant diabetes and acute rejection (n = 1,061). Analyses were adjusted for other recipient, donor, and transplant characteristics. OUTCOMES MEASUREMENTS: Multivariate Cox regression analysis of time to transplant failure (overall and death censored) and mortality (all-cause and cardiovascular).

RESULTS

Median follow-up after 1 year was 548 days (25th-75th percentiles, 334-752 days). During this time, there were 3,047 outcomes of overall transplant failure. New-onset diabetes alone (group 2) was not associated significantly with any study outcomes. Groups 3-6 were associated with higher overall transplant failure risk. However, only groups 4-6 were associated with higher death-censored transplant failure risk. Group 3, 4, and 6 were associated with higher all-cause mortality risk, whereas only groups 3 and 6 were associated with higher cardiovascular mortality risk.

LIMITATIONS

Potential information bias with exposure, covariable, or outcome misclassification; relatively short follow-up.

CONCLUSIONS

Pretransplant diabetes is the major predictor of all-cause and cardiovascular mortality, and acute rejection during the first year is the major predictor of death-censored transplant failure in kidney recipients surviving with a functioning transplant for at least 1 year. The influence of new-onset diabetes on long-term outcomes needs further observation.

Risk factors for new-onset diabetes mellitus in adult liver transplant recipients, an analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database

OBJECTIVE.: To analyze the risk factors for new-onset diabetes mellitus (NODM) in liver transplant recipients using the Organ Procurement and Transplant Network/United Network for Organ Sharing database. METHODS.: Among 20,172 primary liver recipients (age > or =18 years) transplanted between July 2004 and December 2008 in Organ Procurement and Transplant Network/United Network for Organ Sharing databases, 15,463 recipients without pretransplant diabetes were identified. Risk factors for NODM were examined using multivariate Cox regression analysis. RESULTS.: NODM was reported in 26.4% of recipients (median follow-up, 685 days). Independent predictors of NODM development included recipient age (> or = 50 vs. <50 years, hazard ratio [HR]=1.241), African American race (HR=1.147), body mass index (> or = 25 vs. <25, HR=1.186), hepatitis C (HR=1.155), recipient cirrhosis history (HR=1.107), donor age (> or = 60 vs. <60 year, HR=1.152), diabetic donor (HR=1.151), tacrolimus (tacrolimus vs. cyclosporine, HR=1.236), and steroid at discharge (HR=1.594). Living donor transplant (HR=0.628) and induction therapy (HR=0.816) were associated with a decreased risk of NODM. CONCLUSION.: The incidence of NODM was 26.4% in liver recipients with a median follow-up time of 685 days. Identified risk factors for NODM in liver transplantation were similar to that in kidney transplantation. Some of the identified factors are potentially modifiable, including obesity and the choice of immunosuppressive regimens.

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.

African American kidney transplantation survival: the ability of immunosuppression to balance the inherent pre- and post-transplant risk factors

Among organ transplant recipients, the African American population historically has received special attention. This is because secondary to their disposition to certain disease states, for example hypertension, an African American patient has a propensity to reach end-stage renal disease and require renal replacement earlier than a Caucasian patient. Regardless of the initiative to replace dialysis therapy with organ transplantation, the African American patient has many barriers to kidney transplantation, thus extending their time on dialysis and waiting time on the organ transplant list. These factors are among the many negative causes of decreased kidney graft survival, realized before kidney transplantation. Unfortunately, once the African American recipient receives a kidney graft, the literature documents that many post-transplant barriers exist which limit successful outcomes. The primary post-transplant barrier relates to designing proper immunosuppression protocols. The difficulty in designing protocols revolves around (i) altered genetic metabolism/lower absorption, (ii) increased immuno-active cytokines and (iii) detrimental effects of noncompliance. Based on the literature, dosing of immunosuppression must be aggressive and requires a diligent practitioner. Research has indicated that, despite some success with proven levels of immunosuppression, the African American recipient usually requires a higher 'dose per weight' regimen. However, even with aggressive immunosuppressant dosing, African Americans still have worse outcomes than Caucasian recipients. Additionally, many of the targeted sites of action that immunosuppression exerts its effects on have been found to be amplified in the African American population. Finally, noncompliance is the most discouraging inhibitor of long-term success in organ transplantation. The consequences of noncompliance are biased by ethnicity and affect the African American population more severely. All of these factors are discussed further in this review in the hope of identifying an ideal healthcare model for caring for the African American transplant recipient, from diagnosing chronic kidney disease through to successful kidney graft outcomes. An indepth review of the literature is described and organized in a fashion that highlights all of the issues affecting success in African Americans. The compilation of the literature in this review will enable the reader to get closer to understanding the caveats of kidney transplantation in the African American patient, but falls short of delivering an actual 'equation' for post-transplant care in an African American kidney recipient.

Pregnancy and maternal outcomes among kidney transplant recipients

Fertility rates, pregnancy, and maternal outcomes are not well described among women with a functioning kidney transplant. Using data from the Australian and New Zealand Dialysis and Transplant Registry, we analyzed 40 yr of pregnancy-related outcomes for transplant recipients. This analysis included 444 live births reported from 577 pregnancies; the absolute but not relative fertility rate fell during these four decades. Of pregnancies achieved, 97% were beyond the first year after transplantation. The mean age at the time of pregnancy was 29 +/- 5 yr. Compared with previous decades, the mean age during the last decade increased significantly to 32 yr (P < 0.001). The proportion of live births doubled during the last decade, whereas surgical terminations declined (P < 0.001). The fertility rate (or live-birth rate) for this cohort of women was 0.19 (95% confidence interval 0.17 to 0.21) relative to the Australian background population. We also matched 120 parous with 120 nulliparous women by year of transplantation, duration of transplant, age at transplantation +/-5 yr, and predelivery creatinine for parous women or serum creatinine for nulliparous women; a first live birth was not associated with a poorer 20-yr graft or patient survival. Maternal complications included preeclampsia in 27% and gestational diabetes in 1%. Taken together, these data confirm that a live birth in women with a functioning graft does not have an adverse impact on graft and patient survival.

Kidney transplant in diabetic patients: modalities, indications and results

BACKGROUND

Diabetes is a disease of increasing worldwide prevalence and is the main cause of chronic renal failure. Type 1 diabetic patients with chronic renal failure have the following therapy options: kidney transplant from a living donor, pancreas after kidney transplant, simultaneous pancreas-kidney transplant, or awaiting a deceased donor kidney transplant. For type 2 diabetic patients, only kidney transplant from deceased or living donors are recommended. Patient survival after kidney transplant has been improving for all age ranges in comparison to the dialysis therapy. The main causes of mortality after transplant are cardiovascular and cerebrovascular events, infections and neoplasias. Five-year patient survival for type 2 diabetic patients is lower than the non-diabetics' because they are older and have higher body mass index on the occasion of the transplant and both pre- and posttransplant cardiovascular diseases prevalences. The increased postransplant cardiovascular mortality in these patients is attributed to the presence of well-known risk factors, such as insulin resistance, higher triglycerides values, lower HDL-cholesterol values, abnormalities in fibrinolysis and coagulation and endothelial dysfunction. In type 1 diabetic patients, simultaneous pancreas-kidney transplant is associated with lower prevalence of vascular diseases, including acute myocardial infarction, stroke and amputation in comparison to isolated kidney transplant and dialysis therapy.

CONCLUSION

Type 1 and 2 diabetic patients present higher survival rates after transplant in comparison to the dialysis therapy, although the prevalence of cardiovascular events and infectious complications remain higher than in the general population.

Patient survival after kidney transplantation: relationship to pretransplant cardiac troponin T levels

Assessing cardiovascular (CV) risk pretransplant is imprecise. We sought to determine whether cardiac troponin T (cTnT) relates to patient survival posttransplant. The study includes 603 adults, recipients of kidney transplants. In addition to cTnT dobutamine stress echography and coronary angiography were done in 45% and 19% of the candidates respectively. During 28.4 +/- 12.9 months 5.6% of patients died or had a major cardiac event. cTnT levels were elevated (>0.01 ng/ml) in 56.2% of patients. Elevated cTnT related to reduced event-free survival (hazard ratio (HR) = 1.81, CI 1.33-2.45, p < 0.0001) whether those events occurred during the first year or beyond. This relationship was statistically independent of all other variables tested, including older age, reduced left ventricular ejection fraction (EF) and delayed graft function. cTnT levels allowed better definition of risk in patients with other CV risk factors. Thus, event-free survival was excellent in older individuals, patients with diabetes, low EF and those with preexisting heart disease if their cTnT levels were normal. However, elevated cTnT together with another CV risk factor(s) identified patient with very poor survival posttransplant. Pretransplant cTnT levels are strong and independent predictors of posttransplant survival. These results suggest that cTnT is quite helpful in CV risk stratification of kidney transplant recipients.

Identifying specific causes of kidney allograft loss

The causes of kidney allograft loss remain unclear. Herein we investigated these causes in 1317 conventional kidney recipients. The cause of graft loss was determined by reviewing clinical and histologic information the latter available in 98% of cases. During 50.3 +/- 32.6 months of follow-up, 330 grafts were lost (25.0%), 138 (10.4%) due to death with function, 39 (2.9%) due to primary nonfunction and 153 (11.6%) due to graft failure censored for death. The latter group was subdivided by cause into: glomerular diseases (n = 56, 36.6%); fibrosis/atrophy (n = 47, 30.7%); medical/surgical conditions (n = 25, 16.3%); acute rejection (n = 18, 11.8%); and unclassifiable (n = 7, 4.6%). Glomerular pathologies leading to failure included recurrent disease (n = 23), transplant glomerulopathy (n = 23) and presumed nonrecurrent disease (n = 10). In cases with fibrosis/atrophy a specific cause(s) was identified in 81% and it was rarely attributable to calcineurin inhibitor (CNI) toxicity alone (n = 1, 0.7%). Contrary to current concepts, most cases of kidney graft loss have an identifiable cause that is not idiopathic fibrosis/atrophy or CNI toxicity. Glomerular pathologies cause the largest proportion of graft loss and alloinmunity remains the most common mechanism leading to failure. This study identifies targets for investigation and intervention that may result in improved kidney transplantation outcomes.

Survival of patients on the kidney transplant wait list: relationship to cardiac troponin T

Patients waiting for a kidney transplant have high mortality despite careful preselection. Herein, we assessed whether cardiac troponin T (cTnT) can help stratify risk in patients selected for kidney transplantation. cTnT levels were measured in all kidney transplant candidates but the results were not used for patient selection. Among 644 patients placed on the kidney waiting list from 9/2004 to 12/2006, 61% had elevated cTnT levels (>0.01 ng/mL). Higher levels related to diabetes, longer time on dialysis, history of cardiovascular disease and low serum albumin. High cTnT also related to cardiac anomalies, including left ventricular hypertrophy (LVH), wall motion abnormalities and stress-inducible ischemia by dobutamine echo (DSE). However, 54% of patients without these cardiac findings had elevated cTnT. Increasing cTnT levels were associated with reduced survival (HR = 1.729, CI (1.25-2.39), p = 0.01) independently of low serum albumin (0.449 (0.24-0.83), p = 0.011) and history of stroke (3.368 (1.47-7.73), p = 0.0004). The results of the DSE and/or coronary angiography did not relate significantly to survival. However, high cTnT identified patients with abnormal echo findings and poor survival. Wait listed patients with normal cTnT have excellent survival irrespective of other factors. In contrast, high cTnT levels are strongly predictive of poor survival in the kidney transplant waiting list.