Impact of immunosuppressive therapy on arterial stiffness in kidney transplantation: are all treatments the same?

Serum Phenylacetylglutamine among Potential Risk Factors for Arterial Stiffness Measuring by Carotid-Femoral Pulse Wave Velocity in Patients with Kidney Transplantation

Phenylacetylglutamine (PAG), a gut microbiota metabolite, is associated with cardiovascular diseases. Arterial stiffness (AS), which is a marker of aging-associated vascular diseases, is an independent risk factor for cardiovascular morbidity and mortality. This study aimed to assess the correlation between serum PAG levels and AS in kidney transplantation (KT) patients, potentially uncovering new insights into the cardiovascular risks in this population. In this study, 100 KT patients were included. Carotid-femoral pulse wave velocity (cfPWV) was measured, and patients with cfPWV > 10 m/s were categorized as the AS group. Serum PAG levels were assessed using liquid chromatography-tandem mass spectrometry. Thirty KT patients (30.0%) exhibited AS, with higher percentages of diabetes mellitus, older age, and elevated levels of systolic blood pressure, serum fasting glucose, and PAG than the control group. After adjusting for factors significantly associated with AS by multivariate logistic regression analysis, serum PAG, age, fasting glucose levels, and systolic blood pressure were independent factors associated with AS. Furthermore, PAG levels had a negative correlation with the estimated glomerular filtration rate and a positive correlation with cfPWV values. Serum PAG levels are positively associated with cfPWV values and are a biomarker of AS in KT patients.

Cerebrovascular Disease Hospitalization Rates in End-Stage Kidney Disease Patients with Kidney Transplant and Peripheral Vascular Disease: Analysis Using the National Inpatient Sample (2005-2019)

Individuals with end-stage kidney disease (ESKD) face higher cerebrovascular risk. Yet, the impact of peripheral vascular disease (PVD) and kidney transplantation (KTx) on hospitalization rates for cerebral infarction and hemorrhage remains underexplored. Analyzing 2,713,194 ESKD hospitalizations (2005-2019) using the National Inpatient Sample, we investigated hospitalization rates for ischemic and hemorrhagic cerebrovascular diseases concerning ESKD, PVD, KTx, or their combinations. Patients hospitalized with cerebral infarction due to thrombosis/embolism/occlusion (CITO) or artery occlusion resulting in cerebral ischemia (AOSI) had higher rates of comorbid ESKD and PVD (4.17% and 7.29%, respectively) versus non-CITO or AOSI hospitalizations (2.34%, p < 0.001; 2.29%, p < 0.001). Conversely, patients hospitalized with nontraumatic intracranial hemorrhage (NIH) had significantly lower rates of ESKD and PVD (1.64%) compared to non-NIH hospitalizations (2.34%, p < 0.001). Furthermore, hospitalizations for CITO or AOSI exhibited higher rates of KTx and PVD (0.17%, 0.09%, respectively) compared to non-CITO or AOSI hospitalizations (0.05%, p = 0.033; 0.05%, p = 0.002). Patients hospitalized with NIH showed similar rates of KTx and PVD (0.04%) versus non-NIH hospitalizations (0.05%, p = 0.34). This nationwide analysis reveals that PVD in ESKD patients is associated with increased hospitalization rates with cerebral ischemic events and reduced NIH events. Among KTx recipients, PVD correlated with increased hospitalizations for ischemic events, without affecting NIH. This highlights management concerns for patients with KTx and PVD.

Prenatal Exposition to Different Immunosuppressive Protocols Results in Vacuolar Degeneration of Hepatocytes

Immunosuppressive drugs are essential for transplant recipients, since they prolong proper function of graft; however, they affect the morphology and function of organs, including liver. One commonly observed alteration in hepatocytes is vacuolar degeneration. Numerous medications are contraindicated in pregnancy and breastfeeding, mostly due to a lack of data concerning their advert effects. The aim of the current study was to compare the effects of prenatal exposition to different protocols of immunosuppressants on vacuolar degeneration in the hepatocytes of livers of rats. Thirty-two livers of rats with usage of digital analysis of the images were examined. Area, perimeter, axis length, eccentricity and circularity regarding vacuolar degeneration were analysed. The most prominent vacuolar degeneration in hepatocytes in the aspects of presence, area and perimeter was observed in rats exposed to tacrolimus, mycophenolate mofetil and glucocorticoids, and cyclosporine A, everolimus with glucocorticoids.This is the first study that demonstrates the results of the influence of multidrug immnunosuppression distributed in utero on the hepatic tissue of offspring.

Wnt/β-catenin pathway inhibitors, bone metabolism and vascular health in kidney transplant patients

BACKGROUND AND OBJECTIVES

Sclerostin, dickkopf-related protein 1 (DKK1), fibroblast growth factor-23 (FGF23) and α-klotho have been shown to play an important role in bone and vascular disease of chronic kidney disease. We aimed to evaluate the evolution of these bone markers in newly kidney transplanted patients, and whether they are associated with bone metabolism and vascular stiffness.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

This is a longitudinal single-center observational cohort study. Circulating levels of Wnt/β-catenin pathway inhibitors (sclerostin, DKK1, FGF23 and α-klotho), arterial stiffness (carotid-femoral pulse-wave velocity (PWV), carotid-radial PWV, PWV ratio, augmented index) and bone parameters were assessed before (M0), and at 3 (M3) and 6 months (M6) after transplantation. Generalized estimating equations were conducted for comparative analyses between the three time points. We used a marginal structural model for repeated measures for the impact of changes in bone markers on the evolution of arterial stiffness. Multivariate linear regression analyses were performed for the associations between Wnt/β-catenin pathway inhibitors and mineral metabolism parameters.

RESULTS

We included 79 patients (70% male; median age of 53 (44-60) years old). The levels of sclerostin (2.06 ± 1.18 ng/mL at M0 to 0.88 ± 0.29 ng/mL at M6, p ≤ 0.001), DKK1 (364.0 ± 266.7 pg/mL at M0 to 246.7 ± 149.1 pg/mL at M6, p ≤ 0.001), FGF23 (5595 ± 9603 RU/mL at M0 to 137 ± 215 RU/mL at M6, p ≤ 0.001) and α-klotho (457.6 ± 148.6 pg/mL at M0 to 109.8 ± 120.7 pg/mL at M6, p < 0.05) decreased significantly after kidney transplant. Sclerostin and FGF23 were positively associated with carotid-femoral (standardized β = 0.432, p = 0.037 and standardized β = 0.592, p = 0.005) and carotid-radial PWV (standardized β = 0.259, p = 0.029 and standardized β = 0.242, p = 0.006) throughout the 6 months of follow-up. The nature of the associations between bone markers and bone metabolism parameters varies after kidney transplant.

CONCLUSIONS

The circulating levels of Wnt/β-catenin pathway inhibitors and α-klotho significantly decrease after kidney transplantation, while sclerostin and FGF23 levels might be associated with improvement of vascular stiffness and blood pressure.

Association between Long-Term Change in Arterial Stiffness and Cardiovascular Outcomes in Kidney Transplant Recipients: Insights from the TRANSARTE Study

(1) Background: Increased arterial stiffness is associated with cardiovascular (CV) diseases in end-stage renal disease (ESRD) patients, and CV mortality remains higher in kidney transplantation (KT) recipients compared to in the general population. KT is associated with an improvement in arterial stiffness in the early post-transplant period, followed by a potential re-worsening in the late period. In a cohort of KT patients, we evaluated the associations of pulse-wave velocity (PWV) measured at different time-points (pre-transplant, and early and late post-transplant periods) with CV morbi-mortality, as well as the evolution between these measurements with CV morbi-mortality. (2) Methods: Forty KT recipients with a 10-year follow-up were included. The association of PWV with CV events was assessed with multivariable cox analysis. Backward linear regressions were conducted to identify the determinants of PWV at 1 year and those of the long-term evolution of PWV after KT (delta PWV at 1 year—latest PWV). (3) Results: The absence of arterial stiffening during the long-term follow-up after KT is associated with a lower CV outcome rate (HR for the delta PWV = 0.76 (0.58−0.98), p = 0.036). Age at KT is associated with the worsening of arterial stiffness in the late post-transplantation period (β for the delta PWV = −0.104, p = 0.031). A high PWV at 1 year was associated with a potential for recovery during follow-up (β = 0.744, p < 0.0001). (4) Conclusions: The absence of PWV worsening in the late post-transplantation period was significantly associated with a lower risk of CV events, whereas early changes in PWV were not. Finding an intervention capable of reducing long-term PWV could improve the prognosis of KT recipients.

Influence of Belatacept- vs. CNI-Based Immunosuppression on Vascular Stiffness and Body Composition

Background: Arterial stiffness and phase angle (PhA) have gained importance as a diagnostic and prognostic parameter in the management of cardiovascular disease. There are few studies regarding the differences in arterial stiffness and body composition between renal transplant recipients (RTRs) receiving belatacept (BELA) vs. calcineurin inhibitors (CNI). Therefore, we investigated the differences in arterial stiffness and body composition between RTRs treated with different immunosuppressants, including BELA. Methods: In total, 325 RTRs were enrolled in the study (mean age 52.2 years, M −62.7%). Arterial stiffness was determined with an automated oscillometric device. All body composition parameters were assessed, based on bioelectrical impedance analysis (BIA), and laboratory parameters were obtained from the medical files of the patients. Results: We did not detect any significant difference in terms of arterial stiffness and PhA in RTRs undergoing different immunosuppressive regimens, based on CsA, Tac, or BELA. Age was an essential risk factor for greater arterial stiffness. The PhA was associated with age, BMI, time of dialysis before transplantation, and kidney graft function. Conclusion: No significant differences in arterial stiffness and PhA were observed in RTRs under different immunosuppressive regimens. While our data provide additional evidence for arterial stiffness and PhA in RTRs, more research is needed to fully explore these cardiovascular risk factors and the impact of different immunosuppressive regimens.

Less arterial stiffness in kidney transplant recipients than chronic kidney disease patients matched for renal function

BACKGROUND

Chronic kidney disease is associated with a high cardiovascular risk. Compared with glomerular filtration rate-matched CKD patients (CKDps), we previously reported a 2.7-fold greater risk of global mortality among kidney transplant recipients (KTRs). We then examined aortic stiffness [evaluated by carotid-femoral pulse wave velocity (CF-PWV)] and cardiovascular risk in KTRs compared with CKDps with comparable measured glomerular filtration rate (mGFR).

METHODS

We analysed CF-PWV in two cohorts: TransplanTest (KTRs) and NephroTest (CKDps). Propensity scores were calculated including six variables: mGFR, age, sex, mean blood pressure (MBP), body mass index (BMI) and heart rate. After propensity score matching, we included 137 KTRs and 226 CKDps. Descriptive data were completed by logistic regression for CF-PWV values higher than the median (>10.6 m/s).

RESULTS

At 12 months post-transplant, KTRs had significantly lower CF-PWV than CKDps (10.1 versus 11.0 m/s, P = 0.008) despite no difference at 3 months post-transplant (10.5 versus 11.0 m/s, P = 0.242). A lower occurrence of high arterial stiffness was noted among KTRs compared with CKDps (38.0% versus 57.1%, P < 0.001). It was especially associated with lower mGFR, older age, higher BMI, higher MBP, diabetes and higher serum parathyroid hormone levels. After adjustment, the odds ratio for the risk of high arterial stiffness in KTRs was 0.40 (95% confidence interval 0.23-0.68, P < 0.001).

CONCLUSIONS

Aortic stiffness was significantly less marked in KTRs 1 year post-transplant than in CKDps matched for GFR and other variables. This observation is compatible with the view that the pathogenesis of post-transplant cardiovascular disease differs, at least in part, from that of CKD per se.

The incidence and survival after in-hospital cardiopulmonary cerebral resuscitation in end-stage kidney disease patients: A nationwide population-based study

Background

This study analyzed the survival and protective predictors of in-hospital cardiopulmonary cerebral resuscitation (CPCR) to potentially help physicians create effective treatment plans for End-stage kidney disease (ESKD) patients.

Methods

We extracted the data of 7,116 ESKD patients who received their first in-hospital CPCR after initial dialysis between 2004 and 2012 from the National Health Insurance Research Database. The primary outcome was the survival rate during the first in-hospital CPCR. The secondary outcome was the median post-discharge survival.

Results

From 2004 through 2012, the incidence of in-hospital CPCR decreases from 3.97 to 3.67 events per 1,000 admission days (P for linear trend <0.001). The survival rate for the first in-hospital CPCR did not change significantly across the 9 years (P for trend = 0.244), whereas the median survival of post-discharge survival increased significantly from 3.0 months in 2004 to 6.8 months in 2011 (P for linear trend <0.001). In addition, multivariable analysis identified older age as a risk factor and prior intracardiac defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) implantation as a protective factor for in-hospital death during the first in-hospital CPCR.

Conclusion

The incidence of in-hospital CPCR and the duration post-discharge among ESKD patients improved despite there being no significant difference in the survival rate of ESKD patients after CPCP. Either ICD or CRT-D implantation may be advisable for ESKD patients with a high risk of sudden cardiac death.

Arterial Stiffness Assessed by Oscillometric Method in Kidney Transplant, Predialysis, and Dialysis Patients

INTRODUCTION

Chronic kidney disease (CKD) is strongly associated with a higher risk of cardiovascular disease (CV). An important nontraditional risk factor of cardiovascular disease in renal patients is vascular stiffness, which currently can be evaluated by oscillometric measuring of pulse wave velocity (PWV) and heart rate-corrected augmentation index (AIx@75).

AIM

The aim of our study was to compare vascular stiffness between kidney transplant (KTx) recipients, patients on dialysis maintenance, and those in the predialysis period.

MATERIALS AND METHODS

A cross-sectional study of 140 patients (52 in CKD stage 3-4; 37 in CKD stage 5 on hemodialysis maintenance [HD]; and 51 KTx recipients) had their PWV and AIx@75 measured with Mobil-O-Graph (IEM Gmbh, Stolberg, Germany) blood and pulse pressure monitor.

RESULTS

KTx, HD, and CKD G3-4 were comparable in term of age, sex, body mass index, and diagnoses of diabetes mellitus and hypertension. The PWV was higher in the HD group than in the KTx and CKD G3-4 (9.4 m/s vs 8.4 m/s vs 7.9 m/s respectively; P < .05 for HD vs other groups), while the difference between the KTx and CKD G3-4 was not significant. AIx@75 values were similar in the HD and KTx groups (27.1 and 25.6; P > .05) and significantly lower in CDK G3-4 (17.8; P < .05).

CONCLUSIONS

According to our results, the highest CV risk expressed by PWV (vascular stiffness) was found in hemodialysis patients. Although patients with CKD 3-4 and after KTx showed comparable large artery stiffness, transplant recipients additionally showed higher stiffness in smaller arteries as measured by heart rate-corrected AIx.

Late Conversion From Calcineurin Inhibitors to Belatacept in Kidney-Transplant Recipients Has a Significant Beneficial Impact on Glycemic Parameters

Background.

Calcineurin inhibitors (CNIs) and steroids are strongly associated with new-onset diabetes after transplantation, worsening of pre-existing diabetes, and cardiovascular events. We assessed the benefit of conversion from CNI-based to belatacept-based immunosuppression in diabetic kidney-transplant (KT) recipients on glucose control and cardiovascular risk factors.

Methods.

In this retrospective, noncontrolled single-study conducted between May 2016 and October 26, 2018, we recruited KT recipients converted from CNIs to belatacept at least 6 months after KT. The primary endpoint was the evolution of hemoglobin A1c (HbA1c) between baseline and after 6 months of treatment. Secondary endpoints included modifications to antidiabetic drugs, other cardiovascular risk factors, and renal function.

Results.

One hundred and three KT recipients were included. Of these, 26 (25%) had type 2 diabetes. The patients were either receiving oral antidiabetic drugs (n = 21; 75%) or insulin therapy (n = 14; 54%). Overall HbA1c decreased significantly from 6.2 ± 1 to 5.8 ± 1%, P < 0.001. In diabetic patients, HbA1c decreased from 7.2 ± 1 to 6.5 ± 1%, P = 0.001. HbA1c significantly decreased in the subgroup of patients with new-onset diabetes after transplantation and whether diabetes was controlled at inclusion or not (ie, HA1c ≤7% or >7%). Moreover, no diabetic patient increased the number of oral antidiabetic drugs and the dose of basal insulin was not statistically different from baseline to 6 months (16 international unit at baseline and 16 international unit at 6 mo, P = 1). One patient had to start treatment by insulin pump. During follow-up, the renal function, body mass index, and hemoglobin level of all 103 patients remained stable, 2 patients presented acute cellular rejection, and no patient suffered from graft loss.

Conclusions.

A late switch from CNI to belatacept was a valuable therapeutic option for diabetic kidney recipients and substantially improved glycemic parameters.

Reversal of endothelial dysfunction post-immunosuppressive therapy in adult-onset podocytopathy and primary membranous nephropathy

BACKGROUND AND AIMS

The effect of nephrotic syndrome (NS) and its treatment on endothelial dysfunction is not evident. This study assessed endothelial dysfunction in adult-onset NS and its impact of immunosuppressive therapy.

METHODS

Newly diagnosed patients with adult-onset NS (podocytopathy and primary membranous nephropathy (PMN)) and normal renal function were enrolled. Flow mediated vasodilatation (FMD) assessed endothelial function and CD4⁺CD28null T cells, E-selectin and pulse wave velocities (PWV) were measured at baseline and after treatment to characterize this further. Monitoring included monthly proteinuria, serum albumin, creatinine and lipid profile at baseline and post-treatment. The healthy control (HC) included 25 voluntary kidney donors who were assessed for markers of endothelial dysfunction.

RESULTS

Fifty participants with new-onset NS were studied. Amongst the NS group, 26 (52%) patients had PMN, while the remaining 24 (48%) had podocytopathy. Twenty-one (88%) patients in the podocytopathy and 18 (69%) patients in the PMN cohort were in either complete or partial remission at the end of 8 months. FMD at baseline in NS patients was significantly lower as compared to HC (p = 0.002) while PWV (p = 0.007), E-selectin (p < 0.001) and CD4⁺CD28null T cells (p = 0.003) were significantly higher as compared with HC. Following treatment with immunosuppressive medication, FMD increased from 3 to 8% (p < 0.001). PWV also improved from a baseline of 7.70 to 6.65 m/s (p = 0.001). At the end of 8 months, E-selectin decreased significantly from 127 to 82 ng/ml (p = 0.002) while the CD4⁺CD28null T cell population reduced from 5.20 to 3.70% (p = 0.032) of total CD4⁺ cells. In the PMN cohort, despite significant reduction, E-selectin and CD4⁺CD28null T cells at follow-up remained higher than in healthy controls.

CONCLUSION

Immunosuppressive treatment contributes substantially to the improvement of endothelial dysfunction present at baseline in NS patients. Persistent subtle endothelial dysfunction remains in the sub-group of patients with PMN.

Efficacy and Safety of Belatacept Treatment in Renal Allograft Recipients at High Cardiovascular Risk-A Single Center Experience

Belatacept is an attractive option for immunosuppression after renal transplantation. Renal allograft function is superior when compared to calcineurin inhibitor (CNI) based therapy in “de novo” treated patients and it has also been proposed that individuals at high cardiovascular (CV) risk may benefit most. In this retrospective cohort study, we assessed the efficacy and safety of treating patients at high cardiovascular risk with Belatacept (n = 34, for 1194 observation months) when compared to a matched control group of 150 individuals under CNI immunosuppression (for 7309 months of observation). The estimated glomerular filtration rate (eGFR) increased for patients taking Belatacept but decreased during CNI-based therapy (+2.60 vs. −0.89 mL/min/1.73 m²/year, p = 0.006). In a multivariate Cox regression model, Belatacept remained the only significant factor associated with the improvement of eGFR (HR 4.35, 95%CI 2.39–7.93). Belatacept treatment was not a significant risk factor for renal allograft rejection or graft loss. In terms of safety, the only significant risk factor for de novo cardiovascular events was a pre-existing cerebrovascular disease, but Belatacept was not associated with a significant risk reduction. Belatacept treatment was not associated with an increased risk of severe infections, cytomegalo virus (CMV) or BK-virus reactivation, malignancy or death in the multivariate Cox regression analysis. Belatacept is an efficient and safe option for patients after renal transplantation at high cardiovascular risk.

Cardiovascular risk in renal transplant recipients

Successful kidney transplantation offers patients with end-stage renal disease the greatest likelihood of survival. However, cardiovascular disease poses a major threat to both graft and patient survival in this cohort. Transplant recipients are unique in their accumulation of a wide range of traditional and non-traditional cardiovascular risk factors. Hypertension, diabetes, dyslipidaemia and obesity are highly prevalent in patients with end-stage renal disease. These risk factors persist following transplantation and are often exacerbated by the drugs used for immunosuppression in organ transplantation. Additional transplant-specific factors such as poor graft function and proteinuria are also associated with increased cardiovascular risk. However, these transplant-related factors remain unaccounted for in current cardiovascular risk prediction models, making it challenging to identify transplant recipients with highest risk. With few interventional trials in this area specific to transplant recipients, strategies to reduce cardiovascular risk are largely extrapolated from other populations. Aggressive management of traditional cardiovascular risk factors remains the cornerstone of prevention, though there is also a potential role for selecting immunosuppression regimens to minimise additional cardiovascular injury.