Transplantation in the diabetic patient with advanced chronic kidney disease: A task force report

YME1L-mediated mitophagy protects renal tubular cells against cellular senescence under diabetic conditions

BACKGROUND

The senescence of renal tubular epithelial cells (RTECs) is crucial in the progression of diabetic kidney disease (DKD). Accumulating evidence suggests a close association between insufficient mitophagy and RTEC senescence. Yeast mitochondrial escape 1-like 1 (YME1L), an inner mitochondrial membrane metalloprotease, maintains mitochondrial integrity. Its functions in DKD remain unclear. Here, we investigated whether YME1L can prevent the progression of DKD by regulating mitophagy and cellular senescence.

METHODS

We analyzed YME1L expression in renal tubules of DKD patients and mice, explored transcriptomic changes associated with YME1L overexpression in RTECs, and assessed its impact on RTEC senescence and renal dysfunction using an HFD/STZ-induced DKD mouse model. Tubule-specific overexpression of YME1L was achieved through the use of recombinant adeno-associated virus 2/9 (rAAV 2/9). We conducted both in vivo and in vitro experiments to evaluate the effects of YME1L overexpression on mitophagy and mitochondrial function. Furthermore, we performed LC-MS/MS analysis to identify potential protein interactions involving YME1L and elucidate the underlying mechanisms.

RESULTS

Our findings revealed a significant decrease in YME1L expression in the renal tubules of DKD patients and mice. However, tubule-specific overexpression of YME1L significantly alleviated RTEC senescence and renal dysfunction in the HFD/STZ-induced DKD mouse model. Moreover, YME1L overexpression exhibited positive effects on enhancing mitophagy and improving mitochondrial function both in vivo and in vitro. Mechanistically, our LC-MS/MS analysis uncovered a crucial mitophagy receptor, BCL2-like 13 (BCL2L13), as an interacting partner of YME1L. Furthermore, YME1L was found to promote the phosphorylation of BCL2L13, highlighting its role in regulating mitophagy.

CONCLUSIONS

This study provides compelling evidence that YME1L plays a critical role in protecting RTECs from cellular senescence and impeding the progression of DKD. Overexpression of YME1L demonstrated significant therapeutic potential by ameliorating both RTEC senescence and renal dysfunction in the DKD mice. Moreover, our findings indicate that YME1L enhances mitophagy and improves mitochondrial function, potentially through its interaction with BCL2L13 and subsequent phosphorylation. These novel insights into the protective mechanisms of YME1L offer a promising strategy for developing therapies targeting DKD.

[Simultaneous living donor pancreas-kidney transplantation in a patient with type 1 diabetes mellitus after program hemodialysis. Case report]

Simultaneous pancreas-kidney transplantation is an effective treatment option for end-stage renal disease with diabetes mellitus. Successful simultaneous pancreas-kidney transplantation allows achieving euglycemia, stabilizing existing microvascular complications and slowing their progression, improving the patient's quality of life, lipid and calcium-phosphorus metabolism, reducing the risks of cardiovascular events. Therefore, in view of the patient's severe general condition due to prolonged intoxication, hyperglycemia and other complications of chronic kidney disease, the earliest possible surgical treatment with minimization of the patient's stay on dialysis therapy is crucial to improve the outcome of transplantation.

Prevalence and risk factors of urinary tract infection in kidney recipients: a meta-analysis study

BACKGROUND

A kidney recipient's urinary tract infection (UTI) can result in infectious problems and be a risk factor for less successful transplant outcomes. UTI risk factors are still controversial. The present study aimed to investigate the prevalence of UTI and its association with risk factors in kidney recipients.

METHOD

Twenty-six papers published between 2005 and 2022 were retrieved using keywords and searching Medlib, ScienceDirect, PubMed, and other databases. If possible, the pooled prevalence of UTI in kidney recipients and odds ratio (OR) with a 95% confidence interval for each risk factor were calculated. The data were analyzed using the random effects model in R and Stata 14.

RESULTS

The total sample size was 72,600, with an average age of 48.7 years. The pooled prevalence of UTI was 35% (95% CI, 30-40%). The estimated risk factors for UTI were female (OR = 3.13; 95%CI: 2.35-4.17), older age (OR = 1.03; 95%CI: 1-1.05), history of UTI (OR = 1.31; 95%CI) CI: 1.05-1.63), receiving a kidney from a deceased donor (OR = 1.59; 95%CI: 1.23-2.35), long-term use of an indwelling catheter (OR = 3.03; 95%CI: 1.59-6.59), a ureteral stent (OR = 1.54; 95%CI: 1.16-2.06), diabetes (OR = 1.17; 95%CI: 0.97-1.41), hypertension (OR = 1.6; 95%CI: 1.26-2.28), acute rejection process (OR = 2.22; 95%CI: 1.45-3.4), and abnormal urinary tract anatomy (OR = 2.87; 95%CI 1.44-5.74).

CONCLUSION

This meta-analysis revealed that UTIs are a significant problem in kidney recipients. Factors such as female sex, old age, history of UTIs, deceased donor, long-term use of an indwelling catheter, diabetes, acute rejection process, use of ureteral stent, abnormal urinary tract anatomy, and hypertension were related to an increased risk of UTIs in kidney recipients.

Upregulation of TIPE1 in tubular epithelial cell aggravates diabetic nephropathy by disrupting PHB2 mediated mitophagy

Renal tubular epithelial cells (RTECs) are one of the most mitochondria-rich cell types, and are thus vulnerable to mitochondrial dysregulation, which is defined as a pivotal event in tubular damage in diabetic nephropathy (DN). However, the underlying mechanisms remain largely unknown. Here, we investigated the role and mechanisms of tumor necrosis factor alpha-induced protein 8-like 1 (TNFAIP8L1/TIPE1) in high glucose (HG)-induced mitochondrial dysfunction in RTECs and DN progression. TIPE1 expression was predominantly upregulated in RTECs in patients with DN and mice with streptozotocin (STZ)-induced DN. Conditional knockout of Tipe1 in RTECs significantly decreased the urine protein creatinine ratio, renal tubular damage, epithelial-mesenchymal transition, and interstitial fibrosis in STZ-induced mice. RNA sequencing revealed that citrate cycle-related genes were positively enriched in the renal tissues of RTEC-specific Tipe1 knockout mice. Tipe1 deficiency upregulated ATP levels, mitochondrial membrane potential, and respiration rate, but downregulated mitochondrial ROS levels in RTECs. Furthermore, Tipe1 ablation led to enhanced mitophagy in RTECs, indicative of increased LC3II, PINK1, and Parkin expression, but decreased p62 expression in mitochondria. Mechanistically, mass spectrometry screening and co-immunoprecipitation assays revealed the interaction of TIPE1 with prohibitin 2 (PHB2), a crucial mitophagy receptor. Intriguingly, TIPE1 promoted the ubiquitination and proteasomal degradation of PHB2. Subsequently, PHB2 knockdown almost abrogated the improvement of Tipe1 loss on HG-induced tubular cell mitophagy and damage. Thus, TIPE1 disrupts mitochondrial homeostasis in RTECs and promotes tubular damage by destabilizing PHB2 under HG conditions. Hence, TIPE1 may act as a potential therapeutic target to prevent DN progression.

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TIPE1 is highly expressed in RTECs of DN.

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TIPE1 aggravates diabetic renal injury and fibrosis.

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TIPE1 disrupts the mitochondria homeostasis of RTECs by inhibiting mitophagy.

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TIPE1 interacts with and promotes the proteasomal degradation of PHB2.

A Cascade of Structural Barriers Contributing to Racial Kidney Transplant Inequities

Stark racial disparities in access to and receipt of kidney transplantation, especially living donor and pre-emptive transplantation, have persisted despite decades of investigation and intervention. The causes of these disparities are complex, are inter-related, and result from a cascade of structural barriers to transplantation which disproportionately impact minoritized individuals and communities. Structural barriers contributing to racial transplant inequities have been acknowledged but are often not fully explored with regard to transplant equity. We describe longstanding racial disparities in transplantation, and we discuss contributing structural barriers which occur along the transplant pathway including pretransplant health care, evaluation, referral processes, and the evaluation of transplant candidates. We also consider the role of multilevel socio-contextual influences on these processes. We believe focused efforts which apply an equity lens to key transplant processes and systems are required to achieve greater structural competency and, ultimately, racial transplant equity.

Recent Advances and Clinical Outcomes of Kidney Transplantation

Recent advances in surgical, immunosuppressive and monitoring protocols have led to the significant improvement of overall one-year kidney allograft outcomes. Nonetheless, there has not been a significant change in long-term kidney allograft outcomes. In fact, chronic and acute antibody-mediated rejection (ABMR) and non-immunological complications following kidney transplantation, including multiple incidences of primary kidney disease, as well as complications such as cardiovascular diseases, infections, and malignancy are the major factors that have contributed to the failure of kidney allografts. The use of molecular techniques to enhance histological diagnostics and noninvasive surveillance are what the latest studies in the field of clinical kidney transplant seem to mainly focus upon. Increasingly innovative approaches are being used to discover immunosuppressive methods to overcome critical sensitization, prevent the development of anti-human leukocyte antigen (HLA) antibodies, treat chronic active ABMR, and reduce non-immunological complications following kidney transplantation, such as the recurrence of primary kidney disease and other complications, such as cardiovascular diseases, infections, and malignancy. In the present era of utilizing electronic health records (EHRs), it is strongly believed that big data and artificial intelligence will reshape the research done on kidney transplantation in the near future. In addition, the utilization of telemedicine is increasing, providing benefits such as reaching out to kidney transplant patients in remote areas and helping to make scarce healthcare resources more accessible for kidney transplantation. In this article, we discuss the recent research developments in kidney transplants that may affect long-term allografts, as well as the survival of the patient. The latest developments in living kidney donation are also explored.

Diabetic Kidney Disease: Past and Present

Diabetes mellitus (DM) afflicting humans has been recognized as a disease for >3000 years. However, very little was known about its etiology and pathogenesis until about a century ago when increasing knowledge about anatomy and physiology of the human body gradually led to our understanding that the hormone insulin produced by the Islets of Langerhans in the pancreas plays a crucial role in the metabolism of glucose and maintaining the blood sugar level within a normal range. DM is caused by inadequate insulin production (type 1) or insulin resistance (type 2). For thousands of years, DM has been considered as a disease of the kidney; however, with the understanding of the pathogenesis of DM, it became clear that diabetic kidney disease (DKD) is a complication and not a cause of DM. DKD is associated with increased matrix expansion that manifests morphologically as a diffuse or nodular expansion of the mesangium and diffuse thickening of the glomerular and tubular basement membranes. Hyperglycemia plays a crucial role in the development of pathologic changes within the kidney. Once established, DKD usually undergoes a slow but relentless progression to end-stage renal disease. However, recent studies have shown that its progression can be slowed or even reversed by strict control of hyperglycemia. Morphologically, DKD may resemble several other glomerular diseases that must be ruled out before a definitive diagnosis. Patients with DM may also develop nondiabetic glomerular or interstitial diseases with or without DKD. The findings in nephrectomy specimens and the differential diagnoses are presented in detail.

Assessing cardiovascular risk in the prerenal transplant population: Comparison of myocardial perfusion imaging and coronary angiography with risk factor stratification

INTRODUCTION

Patients with end-stage renal disease (ESRD) have a higher incidence of coronary artery disease (CAD). Hence, it is crucial to evaluate CAD before renal transplantation. This study compares the utility of pharmacologic single-photon emission computed-tomography (SPECT) imaging directly to coronary angiography for diagnosis of CAD with correlation to cardiovascular risk factors.

METHOD

Retrospective review of asymptomatic renal failure patients who underwent both SPECT and coronary angiography to identify obstructive CAD between the years 2008-2016. Ninety-four ESRD subjects were evaluated.

RESULTS

Myocardial perfusion SPECT study found, when compared to coronary angiography demonstrated for CAD, the sensitivity of 93.3% with a specificity of 73.4%. Importantly, the negative predictive value for coronary artery disease was 96%. With seven or more cardiac risk factors, 66.7% of patients had obstructive coronary artery disease. Among all the risk factors examined, patients with a previous history of coronary artery disease had a 68% risk of obstructive coronary artery disease.

CONCLUSION

Comparing myocardial perfusion imaging SPECT findings with coronary angiography in patients with ESRD, a sensitivity of 93.3% and a specificity of 73% were observed. Of all the risk factors examined, patient with the previous history of CAD was the single most significant risk factor for CAD in 68% of cases.

Methodological considerations in comparing access to Pre-emptive renal transplantation between SLE and other ESRD causes in the USRDS

BACKGROUND

We compared pre-emptive transplant rates between SLE and non-SLE end-stage renal disease (ESRD) from the U.S. Renal Data System (USRDS) and investigated the potential influence of frequency matching and primary ESRD causes in the non-SLE group.

METHODS

4830 adult SLE patients with incident ESRD from USRDS 2005-2009 were frequency matched by age, sex and race to 4830 patients with incident non-SLE ESRD. Multivariable logistic regression models were used to estimate the odds of pre-emptive transplantation in SLE and non-SLE, and with the non-SLE subgroups by primary ESRD cause.

RESULTS

The odds ratios (OR) of receiving a pre-emptive transplant were similar among non-SLE and SLE (referent group): OR = 1.18 (95% CI: 0.92, 1.50; p = 0.20). However, the ORs for receiving a pre-emptive transplant were 0.19 (95% CI: 0.08, 0.42) in type 2 diabetes ESRD, 0.42 (95% CI: 0.23, 0.75) for hypertension-associated ESRD, 1.67 (95% CI: 1.10, 2.54) in type 1 diabetes ESRD, and 2.06 (95% CI: 1.55, 2.73) for "other" ESRD. In contrast to non-SLE, younger SLE patients were less likely to receive a pre-emptive transplant than older SLE patients.

CONCLUSION

The results of this study provide compelling evidence that major improvements need to be made in optimizing access to pre-emptive transplantation in SLE by addressing sociodemographic disparities and the unique challenges faced by SLE patients. Applying careful matching and selecting appropriate comparison groups in future studies may facilitate the development of effective strategies to address these barriers and to increase the number of pre-emptive renal transplants among SLE patients.

Tacrolimus-Induced Diabetic Ketoacidosis and Effect of Switching to Everolimus: A Case Report

BACKGROUND

New-onset diabetes after transplantation (NODAT) is a common metabolic complication. Most conventional immunosuppressive medications, especially steroids and tacrolimus, are responsible for its development. NODAT may rarely be associated with severe, life-threating complications in kidney transplantation recipients.

CASE REPORT

A 44-year-old man was admitted to our polyclinic for a routine post kidney transplantation visit. He reported polyuria, polydipsia, and general weakness. The patient had undergone preemptive, living-related kidney transplantation 5 weeks previously. Immunosuppressive treatment comprised tacrolimus, prednisolone, and mycophenolate mofetil. Physical examination revealed no abnormalities except signs of mild dehydration. Although he had no history of diabetes before kidney transplantation and his serum fasting glucose levels were within the reference range at the follow-up visits, his laboratory tests revealed high serum glucose and creatinine levels, ketosis, and metabolic acidosis. Our diagnosis was NODAT with diabetic ketoacidosis and prerenal azotemia. Initial treatment comprised intravenous saline and insulin infusion and subsequently involved intensive subcutaneous insulin administration. Despite the intensive insulin therapy and reduction of the tacrolimus dose, sufficient glucose regulation was not achieved. Tacrolimus was switched to everolimus on day 6 of hospitalization. The patient's insulin requirement gradually decreased to one-half of the primary dose over the following several days, and he was discharged on day 10 with successful serum glucose regulation. Although the diabetogenic potential of sirolimus is similar to that of tacrolimus, the impact of everolimus on glucose metabolism remains unclear.

CONCLUSIONS

We have reported a life-threating metabolic complication associated with tacrolimus and successful treatment of NODAT by switching from tacrolimus to everolimus.

Peritoneal dialysis in transplant recipient patients: outcomes and management

Transplant recipient patients performing dialysis represent a growing population in the integrated model of renal replacement therapy. This includes both patients with kidney allograft loss and non-renal organ transplant recipients requiring dialysis. Although a number of possible advantages of peritoneal dialysis over haemodialysis could hypothetically favour its choice when starting dialysis, peritoneal dialysis penetration is relatively residual in this population. Questions about its safety and adequacy in these patients can explain this fact. The purpose of this review is to address unfounded fears and document evidence that peritoneal dialysis should be considered a viable and safe choice in patients returning to dialysis. Specific issues that still need further investigation are also discussed.

Coronary revascularisation in chronic kidney disease. Part 1: stable coronary artery disease

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease, myocardial infarction and cardiovascular death. Detection and treatment of coronary artery disease in CKD patients has been hampered by the limitations of screening tests, the lack of direct evidence for therapeutic interventions in this specific population, and concerns about therapy-related adverse effects. However, these patients potentially have much to gain from conventional strategies used in the general population. This review summarises the current evidence regarding the treatment of coronary artery disease in patients with CKD, with the focus on coronary revascularisation by percutaneous coronary intervention or coronary artery bypass grafting.

Pancreas transplantation: differences in activity between Europe and the United States

BACKGROUND

Although pancreas transplantation (PT) is the treatment of choice in selected diabetic patients, the International Pancreas Transplant Registry (IPTR) has reported important differences in activity between USA and Europe. Of all cases reported, 75% are from USA and only 23% from Europe. Therefore, an analysis of PT activity in selected European countries (SEC) and USA was performed. Materials and methods. We compared national data reports (2002-06) of deceased donors (DD) and deceased solid organ transplantation (DSOT), with special attention to PT activity from 13 SEC countries (375 million inhabitants) and USA (298 million inhabitants).

RESULTS

The number of PT performed in USA was 2-fold higher than in SEC, with the annual rate >2.4 times higher in USA [5.08-4.64 versus 1.61-1.91 per million population (p.m.p.)]. DD and other DSOT activity rates were only slightly higher in USA. In SEC, important differences in PT activity rate were found between countries in the same year (0-6.21 p.m.p.) and in the same country between different years (6.21-2.47 p.m.p.), unrelated to DD or other DSOT activity rate. PT activity rate increased in SEC from 1.61 to 1.91 p.m.p. but decreased in six countries. The waiting list for PT at the end of 2006 was almost 2-fold higher in USA than in SEC.

CONCLUSIONS

Differences in PT activity rate between 13 SEC countries and USA were not related to DD or other DSOT activity. Different waiting list inclusion criteria or incidence of diabetes complications may be considered in more specific studies.

Review article: Coronary artery stenoses: detection and revascularization in renal disease

Cardiovascular events are markedly elevated in those with all degrees of renal impairment compared to the general population. There are well established guidelines in the general population for the management of coronary artery disease, however, similar guidelines have not been established in the renal population. This review examines the current published work on the detection of coronary artery stenoses in addition to summarizing the outcomes of revascularization in patients with kidney disease. Testing for coronary artery disease in the renal population most commonly occurs in dialysis patients as part of their assessment for renal transplantation. While a positive myocardial stress test for the detection of significant coronary artery stenoses is associated with an increased risk of cardiac events, there is no clear information currently showing that cardiovascular testing itself reduces the rate of adverse cardiac events after transplantation. Revascularization of coronary artery stenoses is associated with higher morbidity and mortality in all groups with kidney disease than in the general population, with the exception of renal transplant recipients where the mortality is likely to be similar to that of the general population. There appears to be a benefit in coronary artery bypass surgery compared to percutaneous intervention in those on dialysis and after renal transplant. Currently, there is little data to support coronary artery intervention prior to transplantation in those with asymptomatic coronary artery disease.

Extent and severity of coronary disease and mortality in patients with end-stage renal failure evaluated for renal transplantation

The purpose of this study is to explore the relationship between coronary artery disease (CAD), transplantation status and subsequent mortality in end-stage renal disease (ESRD) patients undergoing evaluation for renal transplantation. Two hundred fifty-three ESRD patients at high risk for CAD underwent coronary angiography as part of a renal transplant evaluation. The cohort was divided into three groups: Group 1 (n = 127) had no vessels with >or=50% stenosis, Group 2 (n = 56) had one vessel with >or=50% stenosis and Group 3 (n = 70) had two or more vessels with >or=50% stenosis. Long-term survival was determined; median follow-up was 3.3 years. The baseline characteristics were similar except for older age and higher proportion of diabetes mellitus, dyslipidemia and peripheral vascular disease in Groups 2 and 3 patients as compared to Group 1. Survival was worse in Group 3 compared to Group 1 (p < 0.0001). Each of the three subgroups had better survival with renal transplantation than those who did not undergo transplantation (p < 0.0001). Although the degree of CAD is related to subsequent mortality, transplantation is associated with better survival regardless of the extent and severity of CAD. Thus, the presence of CAD should not exclude ESRD patients from consideration for this therapy.

Living donor kidney versus simultaneous pancreas-kidney transplant in type I diabetics: an analysis of the OPTN/UNOS database

BACKGROUND AND OBJECTIVES

Transplant options for type I diabetics with end-stage renal disease include simultaneous pancreas-kidney (SPKT), living donor kidney (LDKT), and deceased donor kidney transplant (DDKT). It is unclear whether SPKT offers a survival benefit over LDKT in the current era of transplantation. The authors compared outcomes of kidney transplant recipients with type I diabetes using data from the Organ Procurement and Transplant Network/United Network for Organ Sharing.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adult (age 20 to 59) type I diabetics who received a solitary first-time kidney transplant between 2000 and 2007 were studied. Outcomes included overall kidney graft and patient survival. Multivariate analysis was performed using a stepwise Cox proportional hazards model.

RESULTS

Kidney graft survival was better for recipients of LDKT compared with SPKT (P = 0.008), although patient survival was similar (P = 0.346). On multivariate analysis, LDKT was associated with lower adjusted risks over 72 mo follow-up of kidney graft failure (HR 0.71; 95% CI 0.61 to 0.83) and patient death (HR 0.78; 95% CI 0.65 to 0.94) versus SPKT. Compared with DDKT, SPKT had superior unadjusted kidney graft and patient survival, partly due to favorable SPKT donor and recipient factors.

CONCLUSIONS

Despite more transplants from older donors and among older recipients, LDKT was associated with superior outcomes compared with SPKT and was coupled with the least wait time and dialysis exposure. LDKT utilization should be considered in all type I diabetics with an available living donor, particularly given the challenges of ongoing organ shortage.

Dialysis Services in the Hurricane-Affected Areas in 2005: Lessons Learned

BACKGROUND

Hurricane Katrina resulted in partial or complete devastation of dialysis services throughout the Gulf Coast, including the New Orleans metropolitan area. In the immediate aftermath, dialysis had to be provided to patients by surrounding communities in Louisiana, and ultimately by dialysis programs throughout the nation. Peritoneal dialysis patients, though typically more independent, also endured challenges in continuing dialysis following Hurricane Katrina. Hurricane Rita caused similar damage to the western Gulf Coast at Lake Charles, Louisiana and Beaumont, Texas and further delayed recovery of dialysis services in the New Orleans metropolitan area.

SETTING

A review of the problems created by the disaster provided many opportunities to improve healthcare delivery and to prepare for recovery from the event. Understanding what happened to the delivery of dialysis and chronic kidney disease services allows the opportunity to develop better systems to support this particularly vulnerable population of patients.

CONCLUSION

Many lessons can be learned from these events to minimize future interruption of dialysis services in the face of natural disasters such as hurricanes.

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus on survival and major cardiac events

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus (PTDM) on cardiovascular (CV) disease is not well described. The objectives of the present prospective single-center observational study were to assess the long-term effects of early-diagnosed new-onset PTDM on major cardiac events (MCE; cardiac death or nonfatal acute myocardial infarction) and patient survival. Diabetic status and CV risk factors were assessed in 201 consecutive renal allograft recipients 3 months after transplantation (baseline) during a period of 16 months (1995-96). Follow-up data until January 1, 2004 were obtained from the Norwegian Renal Registry. The 8-year (range 7-9 years) cumulative incidence of MCEs was 7% (nine out of 138) in recipients without diabetes, 20% (seven out of 35) in patients with new-onset PTDM and 21% (six out of 28) in patients with diabetes mellitus before transplantation (DM). Proportional hazards regression analyses (forward stepwise regression) revealed that patients with PTDM had an approximately three-fold increased risk of MCEs as compared with nondiabetic patients (hazard ratio (HR)=3.27, 95% confidence interval (CI)=1.22-8.80, P=0.019). A total of 61 patients (30%) died. Eight-year patient survival was 80% in the nondiabetic group, 63% in the PTDM group and 29% in the DM group, respectively. Pretransplant diabetes (HR=5.09, 95% CI=2.60-9.96, P<0.001), age (HR=1.03, 95% CI=1.01-1.05, P=0.016), cytomegalovirus (CMV) infection (HR=2.66, 95% CI=1.27-5.53, P=0.009), and creatinine clearance (HR=0.98, 95% CI=0.96-1.00, P=0.046), but not PTDM (HR=1.20, 95% CI=0.58-2.49, P=0.621), were independent predictors of death in the multiple Cox regression model. Early-diagnosed PTDM is a predictor of MCEs, but not of all-cause mortality, the first 8 years after renal transplantation.

Cardiac assessment for renal transplantation

Cardiac death is common in patients with end-stage renal failure. Screening for coronary artery disease prior to renal transplantation is advisable in high-risk patients. The optimal screening test has not been defined; however, myocardial perfusion studies are more sensitive than exercise electrocardiography and are less invasive than coronary angiography, which remains the gold standard. The management of coronary artery disease prior to transplantation is contentious. Revascularization of coronary artery stenoses is associated with high mortality and morbidity in the renal failure population, and there is little data to indicate that most patients with asymptomatic coronary lesions will benefit from prophylactic coronary intervention. In addition, beta-blockers and aspirin are under-utilized in the renal population. This paper reviews the literature and proposes algorithms for the cardiac assessment and management of patients prior to renal transplantation.

Validation of a screening protocol for identifying low-risk candidates with type 1 diabetes mellitus for kidney with or without pancreas transplantation

BACKGROUND

Certain clinical risk factors are associated with significant coronary artery disease in kidney transplant candidates with diabetes mellitus. We sought to validate the use of a clinical algorithm in predicting post-transplantation mortality in patients with type 1 diabetes. We also examined the prevalence of significant coronary lesions in high-risk transplant candidates.

METHODS

All patients with type 1 diabetes evaluated between 1991 and 2001 for kidney with/without pancreas transplantation were classified as high-risk based on the presence of any of the following risk factors: age >or=45 yr, smoking history >or=5 pack years, diabetes duration >or=25 yr or any ST-T segment abnormalities on electrocardiogram. Remaining patients were considered low risk. All high-risk candidates were advised to undergo coronary angiography. The primary outcome of interest was all-cause mortality post-transplantation.

RESULTS

Eighty-four high-risk and 42 low-risk patients were identified. Significant coronary artery stenosis was detected in 31 high-risk candidates. Mean arterial pressure was a significant predictor of coronary stenosis (odds ratio 1.68; 95% confidence interval 1.14-2.46), adjusted for age, sex and duration of diabetes. In 75 candidates who underwent transplantation with median follow-up of 47 months, the use of clinical risk factors predicted all eight deaths. No deaths occurred in low-risk patients. A significant mortality difference was noted between the two risk groups (p = 0.03).

CONCLUSIONS

This clinical algorithm can identify patients with type 1 diabetes at risk for mortality after kidney with/without pancreas transplant. Patients without clinical risk factors can safely undergo transplantation without further cardiac evaluation.

New onset hyperglycemia and diabetes are associated with increased cardiovascular risk after kidney transplantation

BACKGROUND

Post-transplant diabetes (PTDM) is a common and serious complication of kidney transplantation. The implications of developing hyperglycemia of lesser severity are not well understood.

METHODS

In this study we used American Diabetes Association (ADA) criteria to assess the incidence of abnormal glycemia post-transplant, the variables that relate to this complication, and the relationship between hyperglycemia and cardiovascular (CV) disease. Included in the study were 490 kidney recipients, transplanted from 1998 to 2003, without a history of diabetes, and with a pretransplant fasting glucose <126 mg/dL.

RESULTS

Within one week post-transplant, 45% of recipients had impaired fasting glycemia (IFG, glucose 100-125 mg/dL), and 21% PTDM (glucose > or =126). One year post-transplant, 33% of patients had IFG, and 13% PTDM. Risk factors for hyperglycemia at one year included: older recipient, male gender, higher BMI, higher pretransplant glucose, and higher glucose one week post-transplant (all P < 0.002 by multivariable analyses). During a follow-up period of 40 +/- 14 months, 12% of recipients had CV events (cardiac, CVA, and/or peripheral). Increasing fasting glucose levels at one, four, and/or 12 months post-transplant were significantly related to CV events. Furthermore, these relationships were independent of other CV risk factors, including: older age, CV events pretransplant, male gender, dyslipidemia, and transplant year. Fasting glucose levels >100 mg/dL were associated with higher incidence of post-transplant cardiac (P= 0.001) and peripheral vascular disease events (P= 0.003).

CONCLUSION

The incidence of post-transplant hyperglycemia and its CV impact have been underestimated. Pretransplant characteristics and, particularly, the glycemia during the first month post-transplant identified patients at risk of PTDM. Increasing glucose levels greater than 100 mg/dL, any time after the first month post-transplant, are associated with increasing CV risk. We postulate that aggressive detection and treatment of post-transplant hyperglycemia may significantly reduce CV morbidity and mortality after kidney transplantation.