Microvascular damage in type 1 diabetic patients is reversed in the first year after simultaneous pancreas-kidney transplantation

Serum angiopoietin-2: a promising biomarker for early diabetic kidney disease in children and adolescents with type 1 diabetes

Albuminuria has been considered the golden standard biomarker for diabetic kidney disease (DKD), but appears once significant kidney damage has already occurred. Angiopoietin-2 (Angpt-2) has been implicated in the development and progression of DKD in adults. We aimed to explore the association of serum Angpt-2 levels with DKD in children and adolescents with type 1 diabetes mellitus (T1DM) of short duration (3-5 years) and to evaluate the predictive power of serum Angpt-2 in the early detection of DKD prior to the microalbuminuric phase. The current cross-sectional study included 90 children divided into three age and sex-matched groups based on urinary albumin-to-creatinine ratio (UACR): microalbuminuric diabetic group (n = 30), non-albuminuric diabetic group (n = 30), and control group (n = 30). All participants were subjected to anthropometric measurements, serum Angpt-2 and fasting lipid profile (total cholesterol, triglycerides, LDL-C, HDL-C, and Non-HDL-C) assessment. Glomerular filtration rate was estimated based on serum creatinine (eGFR-Cr). Higher serum Angpt-2 levels were detected in both diabetic groups compared to controls and in microalbuminuric compared to non-albuminuric diabetic group. There was no detected significant difference in eGFR-Cr values across the study groups. Serum Angpt-2 was positively correlated with triglycerides, LDL, Non-HDL-C, HbA1c, and UACR, while UACR, HbA1c, and Non-HDL-C were independent predictors for serum Angpt-2. Serum Angpt-2 at level of 137.4 ng/L could discriminate between microalbuminuric and non-albuminuric diabetic groups with AUC = 0.960 and at level of 115.95 ng/L could discriminate between the non-albuminuric diabetic group and controls with AUC = 0.976.Conclusion: Serum Angpt-2 is a promising potent biomarker for the detection of early stage of DKD in childhood T1DM before albuminuria emerges. What is Known? • Urine albumin-to-creatinine ratio (UACR) and glomerular filtration rate (GFR) are the golden standard but late biomarkers for DKD. • Angiopoietin-2 has been implicated in the development and progression of DKD in adults with diabetes, but has not been explored in T1DM children with DKD. What is New? • Higher serum angiopoietin-2 was detected in diabetic groups compared to controls and in microalbuminuric compared to non-albuminuric group. • Angiopoietin-2 correlated positively with triglycerides, LDL, Non-HDL-C, HbA1c, and UACR. • Serum angiopoietin-2 is a promising early diagnostic biomarker for DKD in children with T1DM.

The impact of time to death in donors after circulatory death on recipient outcome in simultaneous pancreas-kidney transplantation

The time to arrest donors after circulatory death is unpredictable and can vary. This leads to variable periods of warm ischemic damage prior to pancreas transplantation. There is little evidence supporting procurement team stand-down times based on donor time to death (TTD). We examined what impact TTD had on pancreas graft outcomes following donors after circulatory death (DCD) simultaneous pancreas-kidney transplantation. Data were extracted from the UK transplant registry from 2014 to 2022. Predictors of graft loss were evaluated using a Cox proportional hazards model. Adjusted restricted cubic spline models were generated to further delineate the relationship between TTD and outcome. Three-hundred-and-seventy-five DCD simultaneous kidney-pancreas transplant recipients were included. Increasing TTD was not associated with graft survival (adjusted hazard ratio HR 0.98, 95% confidence interval 0.68-1.41, P = .901). Increasing asystolic time worsened graft survival (adjusted hazard ratio 2.51, 95% confidence interval 1.16-5.43, P = .020). Restricted cubic spline modeling revealed a nonlinear relationship between asystolic time and graft survival and no relationship between TTD and graft survival. We found no evidence that TTD impacts pancreas graft survival after DCD simultaneous pancreas-kidney transplantation; however, increasing asystolic time was a significant predictor of graft loss. Procurement teams should attempt to minimize asystolic time to optimize pancreas graft survival rather than focus on the duration of TTD.

The Diabetes-Heart Disease Connection: Recent Discoveries and Implications

Diabetes and heart disease are 2 prevalent and interconnected conditions with a significant global burden. Understanding the relationship between diabetes and heart disease is crucial for effective management and prevention strategies. This article provides an overview of the 2 conditions, highlighting their types, risk factors, and global prevalence. Recent research findings establish a strong correlation between diabetes and various aspects of cardiovascular health, including coronary artery disease, heart failure, and stroke. Mechanisms such as insulin resistance, inflammation, and oxidative stress contribute to the interplay between diabetes and heart disease. The implications for clinical practice underscore the importance of early detection, risk assessment, and comprehensive management of both conditions. Lifestyle modifications, such as diet, exercise, and weight management, are essential interventions. Pharmacological interventions, including antidiabetic drugs and cardiovascular medications, play a crucial role in treatment. Managing diabetes and heart disease simultaneously poses challenges that require interdisciplinary collaboration among endocrinologists, cardiologists, and primary care physicians. Ongoing research explores personalized medicine and targeted therapies as potential future directions. Continued research and awareness are paramount to mitigate the impact of the diabetes-heart disease connection and improve patient outcomes.

Comprehensive review: Frailty in pancreas transplant candidates and recipients

Well-selected patients with kidney disease and diabetes mellitus who undergo simultaneous kidney-pancreas transplantation often experience dramatic improvements in quality of life and long-term survival compared to those who remain on medical therapy. Over the past several years the importance of frailty in the pancreas transplant candidate and recipient populations has grown. More patients with advanced age have entered the waitlist, and complications from prolonged diabetes, even in younger patients, have created increased evidence of risk for frailty. Given these concerns, and the broad challenges facing pancreas transplantation volumes overall, we generated this review to help establish the impact and implications. We summarize the interplay of immunological factors, aging, environmental factors, diabetes mellitus, and chronic kidney disease that put these patients at risk for frailty. We discuss its measurement and recommend a combination of two instruments (both well-validated and one entirely objective). We describe the outcomes for patients before and after pancreas transplantation who may have frailty, and what interventions can be taken to mitigate its effects. Broader investigation into frailty in the pancreas transplant population is needed to better understand how to select patients for pancreas transplantation and to how manage its consequences thereafter.

Circulating miRNAs and Vascular Injury Markers Associate with Cardiovascular Function in Older Patients Reaching End-Stage Kidney Disease

The prevalence of end-stage kidney disease (ESKD) is rapidly increasing and mostly occurring in patients aged 65 years or older. The main cause of death in these patients is cardiovascular disease (CVD). Novel markers of vascular integrity may thus be of clinical value for identifying patients at high risk for CVD. Here we associated the levels of selected circulating angiogenic miRNAs, angiopoietin-2 (Ang-2) and asymmetric dimethylarginine (ADMA) with cardiovascular structure and function (as determined by cardiovascular MRI) in 67 older patients reaching ESKD that were included from ‘The Cognitive decline in Older Patients with End stage renal disease’ (COPE) prospective, multicentered cohort study. We first determined the association between the vascular injury markers and specific heart conditions and observed that ESKD patients with coronary heart disease have significantly higher levels of circulating ADMA and miR-27a. Moreover, circulating levels of miR-27a were higher in patients with atrial fibrillation. In addition, the circulating levels of the vascular injury markers were associated with measures of cardiovascular structure and function obtained from cardiovascular MRI: pulse wave velocity (PWV), ejection fraction (EF) and cardiac index (CI). We found Ang-2 and miR-27a to be strongly correlated to the PWV, while Ang-2 also associated with ejection fraction. Finally, we observed that in contrast to miR-27a, Ang-2 was not associated with a vascular cause of the primary kidney disease, suggesting Ang-2 may be an ESKD-specific marker of vascular injury. Taken together, among older patients with ESKD, aberrant levels of vascular injury markers (miR-27a, Ang-2 and ADMA) associated with impaired cardiovascular function. These markers may serve to identify individuals at higher risk of CVD, as well as give insight into the underlying (vascular) pathophysiology.

Beneficial Effect of Successful Simultaneous Pancreas-Kidney Transplantation on Plasma Profile of Metalloproteinases in Type 1 Diabetes Mellitus Patients

It is not fully elucidated whether the restoring of normal glucose metabolism after successful simultaneous pancreas-kidney transplantation (SPK) improves vascular wall morphology and function in type 1 diabetic (T1D) patients. Therefore, we compared arterial stiffness, assessed by pulse wave velocity (PWV), carotid intima-media thickness (IMT), and biomarkers of arterial wall calcification in T1D patients after SPK or kidney transplantation alone (KTA). In 39 SPK and 39 KTA adult patients of similar age, PWV, IMT, circulating matrix metalloproteinases (MMPs) and calcification biomarkers were assessed at median 83 months post transplantation. Additionally, carotid plaques were visualized and semi-qualitatively classified. Although PWV and IMT values were similar, the occurrence of atherosclerotic plaques (51.3 vs. 70.3%, p < 0.01) and calcified lesions (35.9 vs. 64.9%, p < 0.05) was lower in SPK patients. There were significantly lower concentrations of MMP-1, MMP-2, MMP-3, and osteocalcin in SPK subjects. Among the analyzed biomarkers, only logMMP-1, logMMP-2, and logMMP-3 concentrations were associated with log HbA_1c. Multivariate stepwise backward regression analysis revealed that MMP-1 and MMP-3 variability were explained only by log HbA_1c. Normal glucose metabolism achieved by SPK is followed by the favorable profile of circulating matrix metalloproteinases, which may reflect the vasoprotective effect of pancreas transplantation.

Markers of the Endothelial Glycocalyx Are Improved following Kidney Transplantation

INTRODUCTION

The endothelial glycocalyx on the vascular luminal surface contributes to endothelial health and function. Damage to this layer is indicative of vascular injury, reflected by increased levels of its shed constituents in serum and an increase in the perfused boundary region (PBR) when measured in sublingual capillaries using the GlycoCheck™ device. We aimed to examine the longitudinal effects of kidney transplantation on the glycocalyx by measuring biochemical markers of the glycocalyx and endothelial dysfunction and the PBR.

METHODS

We recruited healthy controls and stage 5 CKD patients scheduled to undergo a kidney transplant. Investigations were performed before transplant and then 1 and 3 months after transplantation. At each point, blood was collected for hyaluronan, syndecan-1, vascular cell adhesion molecule (VCAM-1), and von Willebrand factor (vWF), and a PBR measurement was performed.

RESULTS

Thirty healthy controls and 17 patients undergoing a kidney transplant were recruited (9 cadaveric and 8 live donation; 12 on dialysis and 5 pre-emptive). Before transplant, transplant recipients had greater evidence of glycocalyx damage than controls. After transplant, PBR improved from median 2.22 (range 1.29-2.73) to 1.98 (1.65-2.25) µm, p = 0.024, and syndecan-1 levels decreased from 98 (40-529) to 36 (20-328) ng/mL, p < 0.001. Similarly, VCAM-1 fell from 1,479 (751-2,428) at baseline to 823 (516-1,674) ng/mL, p < 0.001, and vWF reduced from 3,114 (1,549-5,197) to 2,007 (1,503-3,542) mIU/mL, p = 0.002. Serum levels of hyaluronan remained unchanged.

CONCLUSION

The combination of reduced PBR and syndecan-1 following transplant suggests that transplantation may improve glycocalyx stability at 3 months after transplant.

Imaging the Renal Microcirculation in Cell Therapy

Renal microvascular rarefaction plays a pivotal role in progressive kidney disease. Therefore, modalities to visualize the microcirculation of the kidney will increase our understanding of disease mechanisms and consequently may provide new approaches for evaluating cell-based therapy. At the moment, however, clinical practice is lacking non-invasive, safe, and efficient imaging modalities to monitor renal microvascular changes over time in patients suffering from renal disease. To emphasize the importance, we summarize current knowledge of the renal microcirculation and discussed the involvement in progressive kidney disease. Moreover, an overview of available imaging techniques to uncover renal microvascular morphology, function, and behavior is presented with the associated benefits and limitations. Ultimately, the necessity to assess and investigate renal disease based on in vivo readouts with a resolution up to capillary level may provide a paradigm shift for diagnosis and therapy in the field of nephrology.

The Value of Graft Implantation Sequence in Simultaneous Pancreas-Kidney Transplantation on the Outcome and Graft Survival

BACKGROUND/OBJECTIVES

The sequence of graft implantation in simultaneous pancreas-kidney transplantation (SPKT) warrants additional study and more targeted focus, since little is known about the short- and long-term effects on the outcome and graft survival after transplantation.

MATERIAL AND METHODS

103 patients receiving SPKT in our department between 1999 and 2015 were included in the study. Patients were divided according to the sequence of graft implantation into pancreas-first (PF, n = 61) and kidney-first (KF, n = 42) groups. Clinicopathological characteristics, outcome and survival were reviewed retrospectively.

RESULTS

Donor and recipient characteristics were similar. Rates of post-operative complications and graft dysfunction were significantly higher in the PF group compared with the KF group (episodes of acute rejection within the first year after SPKT: 11 (18%) versus 2 (4.8%); graft pancreatitis: 18 (18%) versus 2 (4.8%), p = 0.04; vascular thrombosis of the pancreas: 9 (14.8%) versus 1 (2.4%), p = 0.03; and delayed graft function of the kidney: 12 (19.6%) versus 2 (4.8%), p = 0.019). The three-month pancreas graft survival was significantly higher in the KF group (PF: 77% versus KF: 92.1%; p = 0.037). No significant difference was observed in pancreas graft survival five years after transplantation (PF: 71.6% versus KF: 84.8%; p = 0.104). Kidney graft survival was similar between the two groups. Multivariate analysis revealed order of graft implantation as an independent prognostic factor for graft survival three months after SPKT (HR 2.6, 1.3-17.1, p = 0.026) and five years (HR 3.7, 2.1-23.4, p = 0.040).

CONCLUSION

Our data indicates that implantation of the pancreas prior to the kidney during SPKT has an influence especially on the early-post-operative outcome and survival rate of pancreas grafts.

Glomerular Endothelial Cell Crosstalk With Podocytes in Diabetic Kidney Disease

Diabetes is the main cause of renal failure worldwide. Complications of the kidney micro-and macro-circulation are common in diabetic patients, leading to proteinuria and can progress to end-stage renal disease. Across the complex interplays aggravating diabetes kidney disease progression, lesions of the glomerular filtration barrier appear crucial. Among its components, glomerular endothelial cells are known to be central safeguards of plasma filtration. An array of evidence has recently pinpointed its intricate relations with podocytes, highly specialized pericytes surrounding glomerular capillaries. During diabetic nephropathy, endothelial cells and podocytes are stressed and damaged. Besides, each can communicate with the other, directly affecting the progression of glomerular injury. Here, we review recent studies showing how in vitro and in vivo studies help to understand pathological endothelial cells-podocytes crosstalk in diabetic kidney disease.

Circulating angiopoietin-2 and angiogenic microRNAs associate with cerebral small vessel disease and cognitive decline in older patients reaching end stage renal disease

BACKGROUND

The prevalence of end-stage renal disease (ESRD) is increasing worldwide, with the majority of new ESRD cases diagnosed in patients aged >60 years. These older patients are at increased risk for impaired cognitive functioning, potentially through cerebral small vessel disease (SVD). Novel markers of vascular integrity may be of clinical value for identifying patients at high risk for cognitive impairment.

METHODS

We aimed to associate the levels of Angiopoietin-2 (Ang-2), asymmetric dimethylarginine (ADMA), and a selection of eight circulating angiogenic miRNAs with SVD and cognitive impairment in older patients reaching ESRD that did not initiate renal replacement therapy yet (n = 129; mean age 75.3 years; mean eGFR 16.4 mL/min). We assessed brain MRI changes of SVD (white matter hyperintensity volume, microbleeds and presence of lacunes) and measures of cognition in domains of memory, psychomotor speed and executive function, comprised in a neuropsychological test battery.

RESULTS

Older patients reaching ESRD showed an unfavorable angiogenic profile, as indicated by aberrant levels of Ang-2 and five angiogenic miRNAs (miR-27a, miR-126, miR-132, miR-223, miR-326), compared to healthy persons and patients with diabetic nephropathy. Moreover, Ang-2 associated with SVD and with the domains of psychomotor speed and executive function, while miR-223 and miR-29a associated with memory function.

CONCLUSIONS

Taken together, these novel angiogenic markers might serve to identify older patients with ESRD at risk of cognitive decline, as well as give insight into the underlying (vascular) pathophysiology.

Diabetic nephropathy alters circulating long noncoding RNA levels that normalize following simultaneous pancreas-kidney transplantation

Simultaneous pancreas-kidney transplantation (SPKT) replaces kidney function and restores endogenous insulin secretion in patients with diabetic nephropathy (DN). Here, we aimed to identify circulating long noncoding RNAs (lncRNAs) that are associated with DN and vascular injury in the context of SPKT. Based on a pilot study and a literature-based selection of vascular injury-related lncRNAs, we assessed 9 candidate lncRNAs in plasma samples of patients with diabetes mellitus with a kidney function >35 mL/min/1.73 m² (DM; n = 12), DN (n = 14), SPKT (n = 35), healthy controls (n = 15), and renal transplant recipients (KTx; n = 13). DN patients were also studied longitudinally before and 1, 6, and 12 months after SPKT. Of 9 selected lncRNAs, we found MALAT1, LIPCAR, and LNC-EPHA6 to be higher in DN compared with healthy controls. SPKT caused MALAT1, LIPCAR, and LNC-EPHA6 to normalize to levels of healthy controls, which was confirmed in the longitudinal study. In addition, we observed a strong association between MALAT1, LNC-EPHA6, and LIPCAR and vascular injury marker soluble thrombomodulin and a subset of angiogenic microRNAs (miR-27a, miR-130b, miR-152, and miR-340). We conclude that specific circulating lncRNAs associate with DN-related vascular injury and normalize after SPKT, suggesting that lncRNAs may provide a promising novel monitoring strategy for vascular integrity in the context of SPKT.

Acromegaly Might Not Negatively Affect Microvascular Circulation

BACKGROUND

Endothelial dysfunction and atherosclerosis are well-known complications of acromegaly. However, current data on microvascular circulation are limited.

AIMS

We aimed to evaluate microvascular circulation in patients with acromegaly.

METHODS

This comparative study included a total of 21 patients with acromegaly and 20 age and sex-matched healthy subjects. A stereomicroscope under 100x magnification was used by a single rheumatologist to evaluate the capillary dimensions (capillary loop length, capillary width) and capillary/mm count in the capillaries of subjects. Statistical data analysis was conducted using the SPSS 15.0 package program.

RESULTS

The mean number of capillaries per ml (Normal ≥8 / ml) in the acromegaly group (AG) and healthy controls (HC) was 7.67 ± 1.88 and 8.67 ± 0.65, respectively (p = 0.04). In the AG and the HC, the number of tortuous capillaries, the mean capillary loop length and the mean capillary width were not different. While the median number of capillaries in the AG was lower than in the HC, it was still within normal limits.

CONCLUSION

Although the number of capillaries were statistically lower in patients with acromegaly, they were within a normal range and the difference was not clinically significant. Moreover, there was no difference in morphological characteristics between the groups. While endothelial dysfunction is the earliest known marker of the atherosclerotic process and is considered to be one of the complications of acromegaly, the disease may not result in impairment of microvasculature of those people afflicted by it. This article is protected by copyright. All rights reserved.

High terminal creatinine donors should not preclude simultaneous kidney and pancreas transplantation

BACKGROUND

Simultaneous pancreas and kidney transplantation (SPK) in the setting of end-stage renal disease offers unmatched outcomes in insulin dependent diabetic patients. Donor pool expansion through the transplantation of kidneys with acute kidney injury (AKI) is controversial.

METHODS

59 SPK transplants were classified by presence of donor AKI, defined as donor terminal creatinine ≥ 1.5x the initial creatinine or donor terminal creatinine > 4.0 mg/dL. Endpoints included graft and patient survival, delayed graft function (DGF), serum creatinine, glomerular filtration rate (GFR), Hemoglobin A1c (HbA1c) and acute rejection.

RESULTS

The donor AKI group (n = 35) had significantly higher rates of DGF (38 v. 9%, p = 0.01). There was no difference in creatinine or GFR at 1, 3, 6 and 12 months. HbA1c was comparable at 3, 6 and 12 months. There was no significant difference in the percentage of patients that required anti-diabetic agents after transplant (14 v. 4%, p = 0.56).

CONCLUSIONS

We observed increased rates of DGF in SPK recipients with donor AKI. However, equivalent outcomes of pancreas and kidney function in both groups were observed.

Angiopoietin 2 and Neuropeptide Y are Associated with Diabetic Kidney Disease in Type 1 Diabetes Mellitus

BACKGROUND

Serum angiopoietin 2 levels have been associated with endothelial dysfunction and diabetic kidney disease. Derangements in autonomous nervous system lead to increased production of vasoconstrictory and angiogenic mediators such as norepinephrine and neuropeptide Y and are associated with increased risk of microvascular complications.

AIM

To investigate associations between angiopoietin 2, neuropeptide Y and diabetic kidney disease in patients with type 1 diabetes mellitus.

METHODS

289 patients with type 1 diabetes mellitus duration > 1 year were included. Patients were stratified according to presence of diabetic nephropathy (macroalbuminuria, estimated glomerular filtration rate<60 ml/min/1.73 m² or end-stage renal disease). Angiopoietin 2 was measured by Luminex technology. Neuropeptide Y was measured by ELISA.

RESULTS

Patients with diabetic nephropathy had significantly increased levels of angiopoietin 2 (4020.5 (2172.4-5778.1) pg/ml vs. 2001.0 (1326.7-2862.7) pg/ml) and neuropeptide Y (18.22 (14.85-21.85) ng/ml vs. 12.91 (9.96-17.07) ng/ml). Higher levels of angiopoietin 2 and neuropeptide Y were observed also in patients with arterial hypertension. Angiopoietin 2 and neuropeptide Y correlated significantly (ρ=0.245, p<0.001). Both biomarkers were significant predictors of estimated glomerular filtration rate and diabetic nephropathy in univariate regression models. In the fully adjusted regression models and after application of a stepwise selection regression method, angiopoietin 2 demonstrated a stronger predictive power for diabetic nephropathy compared to neuropeptide Y.

CONCLUSION

Diabetic nephropathy is associated with increased serum concentrations of angiopoietin 2 (marker of endothelial dysfunction) and neuropeptide Y (marker of sympathetic activity) in type 1 diabetes. Angiopoietin 2 is a more potent predictor of diabetic nephropathy compared to neuropeptide Y.

Diabetic Nephropathy Alters the Distribution of Circulating Angiogenic MicroRNAs Among Extracellular Vesicles, HDL, and Ago-2

Previously, we identified plasma microRNA (miR) profiles that associate with markers of microvascular injury in patients with diabetic nephropathy (DN). However, miRs circulate in extracellular vesicles (EVs) or in association with HDL or the RNA-binding protein argonaute-2 (Ago-2). Given that the EV- and HDL-mediated miR transfer toward endothelial cells (ECs) regulates cellular quiescence and inflammation, we hypothesized that the distribution of miRs among carriers affects microvascular homeostasis in DN. Therefore, we determined the miR expression in EV, HDL, and Ago-2 fractions isolated from EDTA plasma of healthy control subjects, patients with diabetes mellitus (DM) with or without early DN (estimated glomerular filtration rate [eGFR] >30 mL/min/1.73 m²), and patients with DN (eGFR <30 mL/min/1.73 m²). Consistent with our hypothesis, we observed alterations in miR carrier distribution in plasma of patients with DM and DN compared with healthy control subjects. Both miR-21 and miR-126 increased in EVs of patients with DN, whereas miR-660 increased in the Ago-2 fraction and miR-132 decreased in the HDL fraction. Moreover, in vitro, differentially expressed miRs improved EC barrier formation (EV-miR-21) and rescued the angiogenic potential (HDL-miR-132) of ECs cultured in serum from patients with DM and DN. In conclusion, miR measurement in EVs, HDL, and Ago-2 may improve the biomarker sensitivity of these miRs for microvascular injury in DN, while carrier-specific miRs can improve endothelial barrier formation (EV-miR-21/126) or exert a proangiogenic response (HDL-miR-132).

Risk analysis of extended pancreas donor selection criteria

INTRODUCTION

The success of pancreas transplantation, in combination with a stable number of available allografts has resulted in an increasing waiting list. This study investigated donor potential by expanding age and Body Mass Index (BMI) criteria.

METHODS

All reported donors in the Netherlands between 2013 and 2017 were analysed. Risk assessment of extended criteria donors was done by in-depth analysis of donor reports and calculation of the Pancreas Donor Risk Index (PDRI). The PDRI of these extended criteria donors was compared to standard criteria donors to evaluate the increased risk on graft failure.

RESULTS

A total of 1273 donors were reported. Of these donors, 405 donors were reported as pancreas donor, of which 93 (23%) pancreata were transplanted. Extending age criterion with 5 years could result in additional 40 Donation after Brain Death donors and 37 Donation after Circulatory Death donors reported. In 24 (31%) extended age criteria donors the PDRI was below the upper limit of currently transplanted pancreata. Extending BMI criteria to 35 kg/m² could result in an additional 19 (6%) donors reported.

CONCLUSIONS

Extending BMI criteria could result in a slight increase of reported donors. Extending age criteria increased significantly the number of reported donors. In 24 (31%) of the older donors the PDRI showed a reduced risk compared to currently transplanted pancreata. This study suggest that, if other risk factors are absent, pancreata of extended age and/or BMI criteria donors should be considered for transplantation.

Exploring microRNAs, Target mRNAs and their Functions in Leguminous Plant Arachis hypogaea

BACKGROUND

MicroRNAs (miRNAs) are a class of small non-coding, endogenous RNAs that regulate gene expression at post-transcriptional level. In plants, miRNAs are usually of 18-24 nucleotide in length and play humongous role by aiding in development, growth, defense, biotic and abiotic stress responses, etc. Objective: Arachis hypogaea is an economically important oil seed crop and human dietary source cultivated mostly in tropical and subtropical regions. In the present study, an initiative was taken to uncover miRNAs, their targets and functions in this important plant species.

METHOD

Comparative genomics strategy coupled with bioinformatics approaches was deployed for the identification of miRNAs, their corresponding targets and functions by exploiting biological databases and tools.

RESULTS

The study was able to identify 34 conserved miRNA candidates, belonging to 17 miRNA families, contributed by 23 and 3 precursor miRNAs from A. hypogaea Expressed Sequence Tags (EST) and Genome Survey Sequences (GSS), respectively. As well, 495 EST and 917 unigene sequences were predicted as targets for the identified miRNAs. Herein, psRNAtarget server and TargetFinder tool were used to predict unigene targets, whereas comparative genomics strategy was used for identifying EST targets. Functional annotation of the identified targets revealed that the identified miRNAs regulate mRNAs that participate in key biological and metabolic processes. Pathway enrichment analysis using KEGG database also revealed that they regulate important metabolic pathways including antibiotic biosynthesis, biosynthesis of unsaturated fatty acids, amino acids metabolism and flavonoid biosynthesis.

CONCLUSION

The outcome of the study would aid experimental biologists to focus on these miRNAs to facilitate improved crop development and yield.

Simultaneous pancreas-kidney transplantation. Experience of the Doce de Octubre Hospital

INTRODUCTION

Simultaneous pancreas-kidney transplantation (SPKT) constitutes the therapy of choice for diabetes type1 or type2 associated with end-stage renal disease, because is the only proven method to restore normo-glicemic control in the diabetic patient.

METHODS

Retrospective and descriptive study of a series of 175 patients who underwent SPKT from March 1995 to April 2016. We analyze donor and recipient characteristics, perioperative variables and immunosuppression, post-transplant morbi-mortality, patient and graft survival, and risk factors related with patient and graft survival.

RESULTS

Median age of the donors was 28years and mean age of recipients was 38.8±7.3years, being 103 males and 72 females. Enteric drainage of the exocrine pancreas was performed in 113 patients and bladder drainage in 62. Regarding post-transplant complications, the overall rate of infections was 70.3%; graft pancreatitis 26.3%; intraabdominal bleeding 17.7%; graft thrombosis 12.6%; and overall pancreas graft rejection 10.9%. The causes of mortality were mainly cardiovascular and infectious complications. Patient survival at 1, 3 and 5-year were 95.4%, 93% and 92.4%, respectively, and pancreas graft survival at 1, 3 and 5-year were 81.6%, 77.9% y 72.3%, respectively.

CONCLUSIONS

In our 20-year experience of simultaneous pancreas-kidney transplantation, the morbidity rate, and 5-year patient and pancreas graft survivals were similar to those previously reported from the international pancreas transplant registries.

An observational study of microcirculation in dialysis patients and kidney transplant recipients

BACKGROUND

Microcirculatory dysfunction contributes to acute and chronic kidney diseases. To the best of our knowledge, no study has compared differences in microcirculation among healthy volunteers, dialysis patients and kidney transplant recipients.

MATERIALS AND METHODS

Sublingual microcirculation was examined using sidestream dark field imaging and was compared among 90 healthy volunteers, 40 dialysis patients and 40 kidney transplant recipients. The gender effect on microcirculation and the correlations among the microcirculation parameters, age, body mass index, heart rate and blood pressure were analysed.

RESULTS

Total small vessel density, perfused small vessel density and the proportion of perfused small vessels were lower in the dialysis patients than in the healthy volunteers and kidney transplant recipients [total small vessel density; healthy volunteers vs. dialysis patients vs. kidney transplant recipients, 25·2 (2·3) vs. 22·8 (2·6) vs. 24·2 (2·9) mm/mm² , P < 0·001]. Systolic blood pressure showed a weak negative correlation with the microvascular flow index scores in the healthy volunteers. By contrast, systolic blood pressure, diastolic blood pressure and mean arterial pressure showed weak positive correlations with proportion of perfused small vessels and the microvascular flow index scores in the dialysis patients.

CONCLUSIONS

Microcirculatory dysfunction is noted in dialysis patients, and this alteration is ameliorated in KT recipients. The positive correlation between blood pressure and microcirculation in dialysis patients suggests that additional studies should investigate the optimal goal of blood pressure management for dialysis patients.

Impact of graft implantation order on graft survival in simultaneous pancreas-kidney transplantation

The optimal order of revascularization for pancreas and kidney grafts in simultaneous pancreas-kidney transplantation has not been established. In this study, we investigate the influence of graft implantation order on graft survival in SPK. 12 700 transplantations from the Scientific Registry of Transplant Recipients were analyzed retrospectively. Graft implantation order was determined based on the reported ischemia times of pancreas and kidney grafts. Pancreas and kidney graft survivals were analyzed depending on graft implantation order at 3 months and 5 years using Kaplan-Meier plots. Significance was tested with log-rank test and Cox regression model. In 8454 transplantations, the pancreas was implanted first (PBK), and in 4246 transplantations, the kidney was implanted first (KBP). The proportion of lost pancreas grafts at 3 months was significantly lower in PBK (9.4% vs. 10.8%, P = 0.011). Increasing time lag (>2 h) between kidney and pancreas graft implantation in KBP accentuated the detrimental impact on pancreas graft survival (12.5% graft loss at 3 months, P = 0.001). Technical failure rates were reduced in PBK (5.6 vs. 6.9%, P = 0.005). Graft implantation order had no impact on kidney graft survival. In summary, although observed differences are small, pancreas graft implantation first increases short-term pancreas graft survival and reduces rates of technical failure.

Development of immune response to tissue-restricted self-antigens in simultaneous kidney-pancreas transplant recipients with acute rejection

Simultaneous kidney-pancreas transplantation (SKP Tx) is a treatment for end-stage kidney disease secondary to diabetes mellitus. We investigated the role of immune responses to donor human leukocyte antigens (HLA) and tissue-restricted kidney and pancreas self-antigens (KSAgs and PSAgs, respectively) in SKP Tx recipients (SKP TxRs). Sera collected from 39 SKP TxRs were used to determine de novo Abs specific for KSAgs (collagen-IV, Col-IV; fibronectin, FN) and PSAgs (insulin, islet cells, glutamic acid decarboxylase, and pancreas-associated protein-1) by ELISA. KSAg-specific IFN-γ, IL-17, and IL-10 cytokines were enumerated by ELISpot. Abs to donor HLA classes I and II were determined by Luminex assay. Abs to KSAgs and PSAgs were detectable in recipients with rejection compared with stable recipients (P<.05). Kidney-only rejection recipients had increased Abs against KSAgs compared with stable (P<.05), with no increase in Abs against PSAgs. Pancreas-only rejection recipients showed increased Abs against PSAgs compared to stable (P<.05), with no Abs against KSAgs. SKP TxRs with rejection showed increased frequencies of KSAg-specific IFN-γ and IL-17 with reduction in IL-10-secreting cells. SKP TxRs with rejection developed Abs to KSAgs and PSAgs demonstrated increased frequencies of kidney or pancreas SAg-specific IFN-γ and IL-17-secreting cells with reduced IL-10, suggesting loss of peripheral tolerance to SAgs.

Acute Rejection After Kidney Transplantation Associates With Circulating MicroRNAs and Vascular Injury

Supplemental digital content is available in the text.

Background

Acute rejection (AR) of kidney transplants is associated with the loss of endothelial integrity, microvascular rarefaction and, ultimately, graft dysfunction. Circulating angiogenic microRNAs (miRNAs) may serve as markers for microvascular injury. Here, we investigated the short- and long-term effects of AR after kidney transplantation on systemic vascular injury and the associated circulating miRNA profile.

Methods

Systemic vascular injury was determined by measuring capillary tortuosity and density within the oral mucosa as well as by assessing circulating levels of angiopoietin-2/angiopoietin-1 ratio, vascular endothelial growth factor and soluble thrombomodulin. After a pilot study, we selected 48 miRNAs to assess the AR- and microvascular injury associated circulating miRNAs.

Results

In stable transplant recipients (n = 25) and patients with AR (n = 13), which were also studied longitudinally (1, 6, and 12 months post-AR), we found an AR-associated increase in markers of systemic vascular injury, of which vascular endothelial growth factor and soluble thrombomodulin normalized within 1 year after AR. Of the 48 selected miRNAs, 8 were either decreased (miR-135a, miR-199a-3p, and miR-15a) or increased (miR-17, miR-140-3p, miR-130b, miR-122 and miR-192) in AR. Of these, miR-130b, miR-199a, and miR-192 associated with markers of vascular injury, whereas miR-140-3p, miR-130b, miR-122, and miR-192 normalized within 1 year after AR.

Conclusions

AR after kidney transplantation is characterized by systemic microvascular injury and associates with specific circulating miRNA levels.

Alemtuzumab Induction and Delayed Acute Rejection in Steroid-Free Simultaneous Pancreas-Kidney Transplant Recipients

Supplemental digital content is available in the text.

Background

The optimal immunosuppressive regimen in simultaneous pancreas-kidney transplant (SPKT) recipients that prevents acute rejection episodes (AREs) and allows optimal outcome remains elusive.

Methods

This cohort study assessed incidence and time to AREs in 73 consecutive SPKT recipients receiving alemtuzumab induction and steroid-free maintenance with tacrolimus and mycophenolate mofetil. A cohort with single high-dose antithymocyte globulin (ATG; n = 85) and triple therapy served as controls. In addition, we provided mechanistic insights in AREs after alemtuzumab depletion, including composition and alloreactivity of lymphocytes (flow cytometry and mixed lymphocyte reaction) plasma alemtuzumab levels (enzyme-linked immunosorbent assay), and maintenance drug exposure.

Results

Overall number of AREs at 3 years was significantly lower with alemtuzumab versus ATG induction (26.0% vs 43.5%; adjusted hazard ratio, 0.38; P = 0.029). Most AREs (94.6%) with ATG occurred within the first month, whereas 84.2% of AREs with alemtuzumab occurred beyond 3 months. Patients with and without an ARE in the steroid-free alemtuzumab group showed no differences in composition of lymphocytes, or in alemtuzumab levels. Of note, more than two thirds of these AREs were preceded by empiric tacrolimus and/or mycophenolate mofetil dose adjustments due to viral infections, leukopenia, or gastrointestinal symptoms.

Conclusions

Alemtuzumab induction resulted in a significant lower incidence of AREs. Empiric dose adjustments beyond 3 months in the absence of steroids carry a significant risk for subsequent rejection in SPKT recipients.

Simultaneous pancreas-kidney transplantation in patients with type 1 diabetes reverses elevated MBL levels in association with MBL2 genotype and VEGF expression

AIMS/HYPOTHESIS

High levels of circulating mannan-binding lectin (MBL) are associated with the development of diabetic nephropathy and hyperglycaemia-induced vasculopathy. Here, we aimed to assess the effect of glycaemic control on circulating levels of MBL and the relationship of these levels with vascular damage.

METHODS

We assessed MBL levels and corresponding MBL2 genotype, together with vascular endothelial growth factor (VEGF) levels as a marker of vascular damage, in type 1 diabetes patients with diabetic nephropathy before and after simultaneous pancreas-kidney (SPK) transplantation. We included diabetic nephropathy patients (n = 21), SPK patients (n = 37), healthy controls (n = 19), type 1 diabetes patients (n = 15) and diabetic nephropathy patients receiving only a kidney transplant (n = 15). Fourteen diabetic nephropathy patients were followed up for 12 months after SPK.

RESULTS

We found elevated circulating MBL levels in diabetic nephropathy patients, and a trend towards elevated circulating MBL levels in type 1 diabetes patients, compared with healthy control individuals. MBL levels in SPK patients completely normalised and our data indicate that this predominantly occurs in patients with a polymorphism in the MBL2 gene. By contrast, MBL levels in kidney transplant only patients remained elevated, suggesting that glycaemic control but not reversal of renal failure is associated with decreased MBL levels. In line, levels of glucose and HbA1c, but not creatinine levels and estimated GFR, were correlated with MBL levels. VEGF levels were associated with levels of MBL and HbA1c in an MBL-polymorphism-dependent manner.

CONCLUSIONS/INTERPRETATION

Taken together, circulating MBL levels are associated with diabetic nephropathy and are dependent on glycaemic control, possibly in an MBL2-genotype-dependent manner.

Pancreas Transplantation of US and Non-US Cases from 2005 to 2014 as Reported to the United Network for Organ Sharing (UNOS) and the International Pancreas Transplant Registry (IPTR)

This report is an update of pancreas and kidney transplant activities in the US and non-US region in two periods, 2005-2009 and 2010-2014. The aim of the report was to analyze transplant progress and success in the US compared to non-US countries, and to compare trends between the two periods. Between 2005-2009 and 2010-2014, the number of US pancreas transplants declined by over 20%, while the overall number of pancreas transplants performed outside the US has increased. The decline in US numbers is predominantly due to the decline in primary and secondary pancreas after kidney transplants (PAK). During the time period studied, the number of PAK transplants dropped by 50%. In contrast, the number of simultaneous pancreas/kidney transplants (SPK) declined by only 10%, and the number of pancreas transplants alone (PTA) by 20%. Over 90% of pancreas transplants worldwide were performed, with a simultaneous kidney transplant and excellent results. Transplant outcomes in SPK improved significantly because of a decrease in the rates of technical and immunologic graft loss. In 2010-2014 vs. 2005-2009, US SPK transplant patient survival at 1 year post-transplant increased from 95.7% to 97.4%, pancreas graft function from 88.3% to 91.3%, and kidney function from 93.6% to 95.5%. A significant improvement was also noted in PAK transplants. One-year patient survival increased from 96.4% to 97.9% and pancreas graft function from 81.0% to 86.0%. PTA 1-year patient survival remained constant at 97%, and pancreas 1-year graft survival improved from 81.0% to 85.7%. With the decline in the number of transplants, a change towards better pancreas donor selection was observed. In solitary transplants, the donors were primarily young trauma victims, and the pancreas preservation time was relatively short. A general tendency towards transplanting older recipients was noted. In 2010-2014 vs. 2005-2009, PTA recipients 50 years of age or older accounted for 32% vs. 22%, PAK for 28% vs. 22%, and SPK for 22% vs. 20%. This may be due to a relatively lower immunologic graft loss rate, especially in solitary transplants, which historically has been high in young recipients. The number of pancreas transplants in patients with type 2 diabetes and end-stage renal disease has increased, and accounted for 9% of all SPK recipients in 2010-2014.

Improvements in the Management of Diabetic Nephropathy

The burden of diabetes mellitus is relentlessly increasing. Diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) worldwide and a major cause of morbidity and mortality in patients with diabetes. The current standard therapy of diabetic nephropathy involves intensive treatment of hyperglycemia and strict blood pressure control, mainly via blockade of the renin-angiotensin system (RAS). Attention has been drawn to additional beneficial effects of oral hypoglycemic drugs and fibrates on other aspects of diabetic nephropathy. On the other hand, antiproteinuric effects of RAS combination therapy do not seem to enhance the prevention of renal disease progression, and it has been associated with an increased rate of serious adverse events. Novel agents, such as bardoxolone methyl, pentoxifylline, inhibitors of protein kinase C (PKC), sulodexide, pirfenidone, endothelin receptor antagonists, vitamin D supplements, and phosphate binders have been associated with controversial outcomes or significant side effects. Although new insights into the pathogenetic mechanisms have opened new horizons towards novel interventions, there is still a long way to go in the field of DN research. The aim of this review is to highlight the recent progress made in the field of diabetes management based on the existing evidence. The article also discusses novel targets of therapy, with a special focus on the major pathophysiologic mechanisms implicated in the initiation and progression of diabetic nephropathy.

Matrix Metalloproteinase 9 Gene Promoter (rs 3918242) Mutation Reduces the Risk of Diabetic Microvascular Complications

BACKGROUND

Many studies have evaluated the association between matrix metalloproteinase 9 (MMP9) gene promoter polymorphism and diabetic microvascular complications. However, the results are conflicting and inconclusive. The aim of this meta-analysis was to evaluate the association more precisely.

MATERIALS AND METHODS

Studies were retrieved from the PubMed, Embase, Medline, China National Knowledge Infrastructure, Web of Science, and Cochrane databases. All statistical analyses were performed using Review Manager 5.2.

RESULTS

Data were abstracted from four case-control studies that included 446 patients with diabetic microvascular complications and 496 diabetic control subjects. The MMP9-1562 C/T genotype was significantly associated with the risk of diabetic nephropathy after stratification by specific type of microvascular complication (CT + TT vs. CC: OR = 0.42, 95% CI = 0.26-0.69, p = 0.0006; TT vs. CC + CT: OR = 0.37, 95% CI = 0.19-0.76, p = 0.006).

CONCLUSIONS

This study adds to the evidence that MMP9-1562 T gene mutation might reduce the risk of diabetic nephropathy.

Early systemic microvascular damage in pigs with atherogenic diabetes mellitus coincides with renal angiopoietin dysbalance

Background

Diabetes mellitus (DM) is associated with a range of microvascular complications including diabetic nephropathy (DN). Microvascular abnormalities in the kidneys are common histopathologic findings in DN, which represent one manifestation of ongoing systemic microvascular damage. Recently, sidestream dark-field (SDF) imaging has emerged as a noninvasive tool that enables one to visualize the microcirculation. In this study, we investigated whether changes in the systemic microvasculature induced by DM and an atherogenic diet correlated spatiotemporally with renal damage.

Methods

Atherosclerotic lesion development was triggered in streptozotocin-induced DM pigs (140 mg/kg body weight) by administering an atherogenic diet for approximately 11 months. Fifteen months following induction of DM, microvascular morphology was visualized in control pigs (n = 7), non-diabetic pigs fed an atherogenic diet (ATH, n = 5), and DM pigs fed an atherogenic diet (DM+ATH, n = 5) using SDF imaging of oral mucosal tissue. Subsequently, kidneys were harvested from anethesized pigs and the expression levels of well-established markers for microvascular integrity, such as Angiopoietin-1 (Angpt1) and Angiopoietin-2 (Angpt2) were determined immunohistochemically, while endothelial cell (EC) abundance was determined by immunostaining for von Willebrand factor (vWF).

Results

Our study revealed an increase in the capillary tortuosity index in DM+ATH pigs (2.31±0.17) as compared to the control groups (Controls 0.89±0.08 and ATH 1.55±0.11; p<0.05). Kidney biopsies showed marked glomerular lesions consisting of mesangial expansion and podocyte lesions. Furthermore, we observed a disturbed Angpt2/ Angpt1balance in the cortex of the kidney, as evidenced by increased expression of Angpt2 in DM+ATH pigs as compared to Control pigs (p<0.05).

Conclusion

In the setting of DM, atherogenesis leads to the augmentation of mucosal capillary tortuosity, indicative of systemic microvascular damage. Concomitantly, a dysbalance in renal angiopoietins was correlated with the development of diabetic nephropathy. As such, our studies strongly suggest that defects in the systemic microvasculature mirror the accumulation of microvascular damage in the kidney.

Circulating microRNAs associate with diabetic nephropathy and systemic microvascular damage and normalize after simultaneous pancreas-kidney transplantation

Because microvascular disease is one of the most important drivers of diabetic complications, early monitoring of microvascular integrity may be of clinical value. By assessing profiles of circulating microRNAs (miRNAs), known regulators of microvascular pathophysiology, in healthy controls and diabetic nephropathy (DN) patients before and after simultaneous pancreas-kidney transplantation (SPK), we aimed to identify differentially expressed miRNAs that associate with microvascular impairment. Following a pilot study, we selected 13 candidate miRNAs and determined their circulating levels in DN (n = 21), SPK-patients (n = 37), healthy controls (n = 19), type 1 diabetes mellitus patients (n = 15) and DN patients with a kidney transplant (n = 15). For validation of selected miRNAs, 14 DN patients were studied longitudinally up to 12 months after SPK. We demonstrated a direct association of miR-25, -27a, -126, -130b, -132, -152, -181a, -223, -320, -326, -340, -574-3p and -660 with DN. Of those, miR-25, -27a, -130b, -132, -152, -320, -326, -340, -574-3p and -660 normalized after SPK. Importantly, circulating levels of some of these miRNAs tightly associate with microvascular impairment as they relate to aberrant capillary tortuosity, angiopoietin-2/angiopoietin-1 ratios, circulating levels of soluble-thrombomodulin and insulin-like growth factor. Taken together, circulating miRNA profiles associate with DN and systemic microvascular damage, and might serve to identify individuals at risk of experiencing microvascular complications, as well as give insight into underlying pathologies.

Incidence, risk factors, and outcomes of stroke post-transplantation in patients receiving a steroid sparing immunosuppression protocol

Corticosteroid use after transplantation is associated with an increased incidence of cardiovascular events and death. Cerebrovascular disease is a common cause of morbidity and mortality post-renal transplantation; however, a dedicated analysis of cerebrovascular disease in recipients of a steroid sparing protocol has not been reported. The aim of this study was to examine the incidence, risk factors, and outcomes of CVA in transplant recipients receiving a steroid sparing protocol. We retrospectively analyzed 1237 patients who received a kidney alone or a simultaneous pancreas and kidney (SPK) transplant. Fifty-six of 1237 (4.53%) patients had a CVA post-transplant. All-cause mortality was significantly higher in the CVA group compared with the non-CVA group, OR: 3.4 (1.7-7.0), p < 0.001. Factors found to be associated with increased risk of CVA by multivariate analysis were older age, HR: 1.07 (1.04-1.09), p < 0.001; diabetes at the time of transplantation, HR: 2.83 (1.42-5.64), p = 0.003; corticosteroid use pre-transplant, HR: 3.27 (1.29-8.27), p = 0.013 and recipients of a SPK, HR: 4.03 (1.85-8.79), p < 0.001. This study has identified subgroups of patients who are at increased risk of CVA post-transplant in patients otherwise receiving a steroid sparing immunosuppression protocol.

Association of kidney function with changes in the endothelial surface layer

BACKGROUND AND OBJECTIVES

ESRD is accompanied by endothelial dysfunction. Because the endothelial glycocalyx (endothelial surface layer) governs interactions between flowing blood and the vessel wall, perturbation could influence disease progression. This study used a novel noninvasive sidestream-darkfield imaging method, which measures the accessibility of red blood cells to the endothelial surface layer in the microcirculation (perfused boundary region), to investigate whether renal function is associated with endothelial surface layer dimensions.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Perfused boundary region was measured in control participants (n=10), patients with ESRD (n=23), participants with normal kidney function after successful living donor kidney transplantation (n=12), and patients who developed interstitial fibrosis/tubular atrophy after kidney transplantation (n=10). In addition, the endothelial activation marker angiopoietin-2 and shed endothelial surface layer components syndecan-1 and soluble thrombomodulin were measured using ELISA.

RESULTS

Compared with healthy controls (1.82 ± 0.16 µm), ESRD patients had a larger perfused boundary region (+0.23; 95% confidence interval, 0.46 to <0.01; P<0.05), which signifies loss of endothelial surface layer dimensions. This large perfused boundary region was accompanied by higher circulating levels of syndecan-1 (+57.71; 95% confidence interval, 17.38 to 98.04; P<0.01) and soluble thrombomodulin (+12.88; 95% confidence interval, 0.29 to 25.46; P<0.001). After successful transplantation, the perfused boundary region was indistinguishable from healthy controls (without elevated levels of soluble thrombomodulin or syndecan-1). In contrast, however, patients who developed interstitial fibrosis and tubular atrophy showed a large perfused boundary region (+0.36; 95% confidence interval, 0.09 to 0.63; P<0.01) and higher levels of endothelial activation markers. In addition, a significant correlation between perfused boundary region, angiopoietin-2, and eGFR was observed (perfused boundary region versus GFR: Spearman's ρ=0.31; P<0.05; perfused boundary region versus angiopoietin-2: Spearman's ρ=-0.33; P<0.05).

CONCLUSION

Reduced renal function is strongly associated with low endothelial surface layer dimensions. After successful kidney transplantation, the endothelial surface layer is indistinguishable from control.