Post-transplant dyslipidemia: Mechanisms, diagnosis and management

Complications Associated with Immunosuppressive Agents in Solid Organ Transplant Recipients: A Nationwide Analysis

Background: Immunosuppressive therapies are vital for solid organ transplant (SOT) recipients to ensure graft survival, but long-term use can lead to complications. This study aimed to comprehensively evaluate the complications associated with immunosuppressive agents across different types of major SOTs. Methods: In a retrospective cohort study using a national claims database, we analyzed adult SOT recipients who began immunosuppressive therapy from 2007 to 2018. We identified complications such as infections, acute kidney injury, hypertensive emergencies, chronic kidney disease, hypertension, diabetes, dyslipidemia, and osteoporosis. These outcomes were determined through diagnostic codes, medication usage data, and hospital or emergency department visits. Results: Among 30,997 transplants with three-year follow up, complication rates varied by transplant type. Pancreatic transplant recipients had the lowest complication rate (225.9 per 1000 patient-years), while lung transplant recipients experienced the highest rate (823.9 per 1000 patient-years). Serious infections and chronic kidney disease were most common 2 to 6 months post transplant. Other complications, like acute kidney injury, hypertensive emergencies, hypertension, diabetes, dyslipidemia, and osteoporosis, were predominantly observed in the first month. Opportunistic infections peaked between 7 months and 1 year after transplantation. Conclusions: This study emphasizes the varied complications related to immunosuppressive therapy among different SOT recipients, delineating specific timeframes for each complication and maintenance regimen.

Statin Use in Special Populations for the Prevention of Cardiovascular Disease in Adults

PURPOSE OF REVIEW

Outcome benefits for HMG-CoA reductase inhibitor (statin) use in the prevention of atherosclerotic cardiovascular disease (ASCVD) are well established and yet, statins remain underutilized with only half of eligible individuals receiving them among certain vulnerable populations. This review critically examines available data to provide a summary of the current evidence for statin use in select populations.

RECENT FINDINGS

Lipid management can be more complex in patients with chronic kidney disease (CKD), organ transplants, metabolic dysfunction associated with steatotic liver disease (MASLD), and human immunodeficiency virus (HIV). Statins are generally safe and effective to reduce the burden of ASCVD among these highly heterogeneous groups of patients and should be considered with careful attention to their concomitant disease state. Herein, we focus on appropriate statin use in these challenging to treat conditions, their relationship with increased ASCVD risk, and approaches to statin use for ASCVD risk reduction. Although further research is needed to define optimal therapy in select high risk groups for ASCVD prevention, statins are proven to be clinically efficacious, safe, and cost-effective for ASCVD prevention, warranting greater efforts to increase their use.

Obesity-associated Inflammation and Alloimmunity

Obesity is a worldwide health problem with a rapidly rising incidence. In organ transplantation, increasing numbers of patients with obesity accumulate on waiting lists and undergo surgery. Obesity is in general conceptualized as a chronic inflammatory disease, potentially impacting alloimmune response and graft function. Here, we summarize our current understanding of cellular and molecular mechanisms that control obesity-associated adipose tissue inflammation and provide insights into mechanisms affecting transplant outcomes, emphasizing on the beneficial effects of weight loss on alloimmune responses.

Novel therapeutic agents for cardiometabolic risk mitigation in heart transplant recipients

Heart transplant (HT) recipients experience high rates of cardiometabolic disease. Novel therapies targeting hyperlipidemia, diabetes, and obesity, including proprotein convertase subtilisin/kexin inhibitors, sodium-glucose cotransporter-2 inhibitors, and glucagon-like peptide-1 agonists, are increasingly used for cardiometabolic risk mitigation in the general population. However, limited data exist to support the use of these agents in patients who have undergone heart transplantation. Herein, we describe the mechanisms of action and emerging evidence supporting the use of novel pharmacologic agents in the post-HT setting for cardiometabolic risk mitigation and review evidence supporting their ability to modulate immune pathways associated with atherogenesis, epicardial adipose tissue, and coronary allograft vasculopathy.

Managing Dyslipidemia in Chronic Kidney Disease: Implications for Cardiovascular and Renal Risk

PURPOSE OF REVIEW

The review aims to address the complex relationship between dyslipidemia and chronic kidney disease (CKD), emphasizing its dual role in driving cardiovascular disease (CVD) risk and contributing to CKD progression. It explores pathophysiological mechanisms, highlights recent biomarker discoveries, and evaluates contemporary and emerging lipid-lowering therapies tailored for CKD patients.

RECENT FINDINGS

Recent studies have highlighted the inadequacy of traditional lipid markers like LDL-C in reflecting cardiovascular risk in CKD. Novel biomarkers, such as remnant cholesterol and lipoprotein(a), demonstrate stronger associations with adverse outcomes. Emerging lipid-lowering agents, including bempedoic acid, pemafibrate, and PCSK9 inhibitors, show promise for risk reduction, especially in non-dialysis-dependent CKD. However, evidence remains limited for advanced stages of CKD and dialysis patients. Furthermore, alterations in lipid metabolism, such as dysfunctional HDL and triglyceride-rich lipoproteins, are now recognized as significant contributors to CVD and renal damage in CKD populations. Dyslipidemia is a pivotal modifiable risk factor in CKD, exacerbating both cardiovascular risk and disease progression. While statins remain the cornerstone of therapy in early-to-moderate CKD, their efficacy diminishes in advanced stages. The advent of novel therapeutic options and a deeper understanding of dyslipidemia's pathophysiology hold potential for improving outcomes. Future research should prioritize personalized approaches, focusing on the unique metabolic derangements of CKD and advancing treatments for high-risk and dialysis-dependent patients.

Severe Hypertriglyceridemia in a Patient Treated With Sirolimus for Graft-vs-Host Disease Prophylaxis

Hypertriglyceridemia is an important and well documented adverse effect caused by the immunosuppressive agent sirolimus. Patients treated with sirolimus require frequent monitoring of blood lipid panels and prompt treatment with appropriate triglyceride-lowering therapies. We report the case of an asymptomatic 65-year-old female stem cell transplant recipient who developed extreme hypertriglyceridemia with levels > 19,000 mg/dL (214 mmol/L) (reference range, < 150 mg/dL [< 1.7 mmol/L]), secondary to sirolimus for prophylaxis of graft-vs-host disease. Acute treatment included admission to the intensive care unit for initiation of an intravenous insulin infusion, low-fat diet, and discontinuation of sirolimus. These measures, in addition to initiation of oral triglyceride-lowering agents and improved glycemic control, led to substantial improvement in triglyceride levels.

Analysis of the Correlation between Hypercholesterolemia and Increased Cardiovascular Morbidity and Mortality among Adult Kidney Transplant Recipients

INTRODUCTION

The correlation between hypercholesterolemia and cardiovascular disease in kidney transplant recipients (KTRs) remains uncertain. We sought to characterize the association between abnormal cholesterol profiles and cardiovascular morbidity and mortality in this unique population.

METHODS

This retrospective cohort study was conducted at a single center and included all adult KTR, transplanted between January 2005 and April 2014. The primary outcome was major adverse cardiovascular events (MACE) while the secondary outcome was the composite outcome of MACE and all-cause mortality. Exposure to abnormal cholesterol levels was calculated using a time-weighted average calculation. MACE and mortality risk were analyzed using a multivariate time-varying Cox model.

RESULTS

The final cohort comprised 737 KTR, with a median follow-up of 2,920 days. A total of 126 patients (17.1%) experienced MACE. High LDL-C levels and MACE risk were correlated by multivariate analysis (HR 1.008 per mg/dL, 95% CI: 1.001-1.016), while low HDL-C levels were not significantly associated with MACE (HR 0.992 per mg/dL, 95% CI: 0.976-1.009). A higher LDL-C/HDL-C ratio was significantly associated with an increased risk of MACE in multivariate analyses (HR 1.502 per unit, 95% CI: 1.147-1.968), and also correlated with the composite outcome (HR 1.35 per unit, 95% CI: 1.06-1.71).

CONCLUSIONS

A high LDL-C/HDL-C ratio is predictive of an increased risk of cardiovascular morbidity and mortality in KTRs. These findings emphasize the significance of the LDL-C/HDL-C ratio as a valuable marker of cardiovascular risk and support current recommendations to improve hypercholesterolemia in this high-risk group.

Posttransplant complications: molecular mechanisms and therapeutic interventions

Posttransplantation complications pose a major challenge to the long-term survival and quality of life of organ transplant recipients. These complications encompass immune-mediated complications, infectious complications, metabolic complications, and malignancies, with each type influenced by various risk factors and pathological mechanisms. The molecular mechanisms underlying posttransplantation complications involve a complex interplay of immunological, metabolic, and oncogenic processes, including innate and adaptive immune activation, immunosuppressant side effects, and viral reactivation. Here, we provide a comprehensive overview of the clinical features, risk factors, and molecular mechanisms of major posttransplantation complications. We systematically summarize the current understanding of the immunological basis of allograft rejection and graft-versus-host disease, the metabolic dysregulation associated with immunosuppressive agents, and the role of oncogenic viruses in posttransplantation malignancies. Furthermore, we discuss potential prevention and intervention strategies based on these mechanistic insights, highlighting the importance of optimizing immunosuppressive regimens, enhancing infection prophylaxis, and implementing targeted therapies. We also emphasize the need for future research to develop individualized complication control strategies under the guidance of precision medicine, ultimately improving the prognosis and quality of life of transplant recipients.

Prevention and rehabilitation after heart transplantation: A clinical consensus statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Post-Liver Transplant Metabolic Syndrome

Non-alcoholic steatohepatitis (NASH) is the second most frequent cause of liver transplantation following alcoholic liver disease. With longer follow-up and increased survival rates, the occurrence rate of the metabolic syndrome is increasing with time among liver transplant recipients. Reappearances of non-alcoholic fatty liver disease after transplantation, both as recurring cases and new instances, are prevalent; nonetheless, the recurrence of fibrosis is minimal. Recognizing populations at elevated risk and enhancing the management of metabolic-related conditions are crucial for maintaining a healthy transplanted organ, particularly considering the prolonged utilization of immunosuppressive treatments. Furthermore, NASH-related cirrhosis patients who had transplant are at a greater risk of cardiovascular, renal events and increased incidence of cancer, necessitating a unique care strategy. This review discusses post-transplant metabolic syndrome, risk factors, pathogenesis, diagnosis, prevention strategy, recurrent and de novo NAFLD and customized immunosuppression.

Prevention and Rehabilitation After Heart Transplantation: A Clinical Consensus Statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a Section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus statement focuses on the importance and the characteristics of prevention and rehabilitation designed for HTx recipients.

Management of kidney transplant recipients for primary care practitioners

Patients with kidney transplants have a significant co-morbidity index, due to a high number of pre-existing conditions and use of immunosuppression medications. These patients are at higher risk of developing conditions such as hypertension, dyslipidemia, post-transplant diabetes, cardiovascular events, and anemia. Moreover, they are particularly susceptible to infections such as urinary tract infections or pyelonephritis, cancers, and gastrointestinal complications such as diarrhea, which in turn may be attributed to medication adverse effects or infectious causes. Along with these concerns, meticulous management of electrolytes and allograft function is essential. Prior to prescribing any new medications, it is imperative to exercise caution in identifying potential interactions with immunosuppression drugs. This review aims to equip primary care practitioners to address these complex issues and appropriate methods of delivering care to this rapidly growing highly susceptible group.

Managing dyslipidemia in solid organ transplant patients

Solid organ transplant recipients face an increased risk of dyslipidemia, which contributes to cardiovascular complications. Commonly used drugs such as ciclosporin and tacrolimus can aggravate and cause dyslipidemia. Immunosuppressive drugs particularly ciclosporin and tacrolimus are also known to worsen dyslipidemia in transplant recipients. Mammalian target of rapamycin (mTOR) inhibitors like sirolimus and everolimus also alter lipid metabolism. Lifestyle and dietary modifications should be encouraged. Careful consideration of immunosuppressant choices is also vital to control dyslipidemia. Statins are recommended as first-line agents for lipid-lowering therapy, with consideration for potential drug interactions. Other options, such as ezetimibe and nicotinic acid, may be considered as alternatives. The management of dyslipidemia in renal transplant patients mainly involves statin therapy, although the clinical effectiveness in this population is not well-documented. Lifestyle modifications, careful drug selection, and statin therapy are key components in managing dyslipidemia in solid organ transplant patients.

Nutrition support considerations in pediatric small bowel transplantation

Enteral autonomy is the primary goal of intestinal failure therapy. Intestinal transplantation (ITx) is an option when enteral autonomy cannot be achieved and management complications become life-threatening. The purpose of this review is to summarize existing medical literature related to nutrition requirements, nutrition status, and nutrition support after pediatric ITx. Achieving or maintaining adequate growth after intestinal transplant in children can be challenging because of episodes of rejection that require the use of corticosteroids, occurrences of infection that require a reduction or discontinuation of enteral or parenteral support, and fat malabsorption caused by impaired lymphatic circulation. Nutrient requirements should be assessed and modified regularly based on nutrition status, growth, ventilatory status, wound healing, and the presence of complications. Parenteral nutrition (PN) should be initiated as a continuous infusion early postoperatively. Enteral support should be initiated after evidence of graft bowel function and in the absence of clinical complications. Foods high in simple carbohydrates should be limited, as consumption may result in osmotic diarrhea. Short-term use of a fat-free diet followed by a low-fat diet may reduce the risk of the development of chylous ascites. Micronutrient deficiencies and food allergies are common occurrences after pediatric ITx. Enteral/oral vitamin and mineral supplementation may be required after PN is weaned. Nutrition management of children after ITx can be challenging for all members of the healthcare team. Anthropometric parameters and micronutrient status should be monitored regularly so that interventions to promote growth and prevent or reverse nutrient deficiencies can be implemented promptly.

Optimization of Hypercholesterolemia Treatment after Heart Transplant: The Role of PCSK9 Inhibitors

BACKGROUND

Previous studies have reported the benefit of statins after heart transplant (HT). However, the use of high-dose statins might be limited in some HT patients due to intolerance and interactions with immunosuppression or might not be enough to achieve low-density lipoprotein (LDL) cholesterol goals. Hyperlipidemia has been associated with coronary allograft vasculopathy. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors might be a safe and effective option in HT patients with suboptimal lipid control.

METHODS

In a retrospective study, we identified HT patients in our center with LDL cholesterol >100 mg/dL, after diet modifications and up-titration of statins to maximum tolerated dose, treated with PCSK9i. The primary endpoint was LDL reduction one month after, and secondary endpoints were the development of donorspecific HLA antibodies (DSA) and the presence of coronary allograft vasculopathy or rejection.

RESULTS

From January, 2018, to January, 2024, we identified five HT patients treated with PCSK9 inhibitors. In all cases, evolocumab was used. A significant reduction in LDL cholesterol was observed (151.6 ± 13.5 mg/dl to 72.4 ± 14.6 mg/dl; p = 0.04, mean reduction 75.7 ± 14.1 mg/dl), as well as in total cholesterol (231 ± 34.6 mg/dl to 152.2 ± 38.9 mg/dl; p < 0.01, mean reduction 78.8 ± 22.2 mg/dl). A significant increase in HDL cholesterol was not observed (45.4 ± 10.9 mg/dl to 46.2 ± 11.1 mg/dl; p = 0.60). One patient developed DSA five years after treatment onset. Rejection and coronary allograft vasculopathy were not observed.

CONCLUSION

PCSK9 inhibitors are safe and effective in reducing LDL in HT patients. However, larger studies are needed to clarify if they can reduce the development of coronary allograft vasculopathy.

The Biological Parallels Between Atherosclerosis and Cardiac Allograft Vasculopathy: Implications for Solid Organ Chronic Rejection

Atherosclerosis and solid organ chronic rejection are pervasive chronic disease states that account for significant morbidity and mortality in developed countries. Recently, a series of shared molecular pathways have emerged, revealing biological parallels from early stages of development up to the advanced forms of pathology. These shared mechanistic processes are inflammatory in nature, reflecting the importance of inflammation in both disorders. Vascular inflammation triggers endothelial dysfunction and disease initiation through aberrant vasomotor control and shared patterns of endothelial activation. Endothelial dysfunction leads to the recruitment of immune cells and the perpetuation of the inflammatory response. This drives lesion formation through the release of key cytokines such as IFN-y, TNF-alpha, and IL-2. Continued interplay between the adaptive and innate immune response (represented by T lymphocytes and macrophages, respectively) promotes lesion instability and thrombotic complications; hallmarks of advanced disease in both atherosclerosis and solid organ chronic rejection. The aim of this study is to identify areas of overlap between atherosclerosis and chronic rejection. We then discuss new approaches to improve current understanding of the pathophysiology of both disorders, and eventually design novel therapeutics.

Lipid abnormalities in pediatric kidney transplant recipients on steroid withdrawal maintenance immunosuppression

BACKGROUND

Dyslipidemia is a modifiable risk factor for cardiovascular disease. The prevalence of dyslipidemia in pKTR (pediatric kidney transplant recipients) under modern immunosuppression remains unknown. We determined the prevalence, risk factors, co-morbidities, and treatment patterns of lipid abnormalities in pediatric kidney transplant recipients on steroid withdrawal immunosuppression.

METHODS

pKTR (age ≤ 21 years) at a single center on steroid withdrawal immunosuppression underwent lipid screening between January 1, 2020, and September 30, 2022. Continuous and categorical variables were compared using the Wilcoxon rank-sum and chi-square or Fisher's exact tests, respectively. The correlation between total cholesterol and BMI (body mass index) was assessed using Pearson's product-moment correlation, and predictors of lipid abnormalities were evaluated using the multivariable logistic regression.

RESULTS

A total of 96 patients were included, with a median post-transplant time of 2.5 years (IQR: 1.3-5.4). Of the total, 64.6% (n = 62) of patients had a fasting lipid abnormality. We found a significant linear correlation between total cholesterol and BMI (r = 0.38, p = 0.0022). After multivariable adjustment, every 1 ml/min/1.73 m2 increase in eGFR was associated with a 2% lower odds of a lipid abnormality (OR 0.979, p = 0.026). Obesity, hypertension, and left ventricular hypertrophy were similar between those with and without lipid abnormalities, while insulin-treated diabetes was more prevalent in recipients with lipid abnormalities (12.9% vs. 0%, p = 0.047). Only 36.5% of patients (n = 19) were referred to a dietician and/or lipid specialist; one received statin therapy.

CONCLUSIONS

Lipid abnormalities are highly prevalent in pKTR, but therapeutic intervention is infrequent. Calcineurin inhibition without corticosteroids may not be protective; however, higher eGFR is associated with a lower prevalence of lipid abnormalities. A higher resolution version of the Graphical abstract is available as Supplementary information.

Immunosuppressive Agents-Effects on the Cardiovascular System and Selected Metabolic Aspects: A Review

The widespread use of immunosuppressive drugs makes it possible to reduce inflammation in autoimmune diseases, as well as prevent transplant rejection in organ recipients. Despite their key action in blocking the body's immune response, these drugs have many side effects. These actions primarily affect the cardiovascular system, and the incidence of complications in patients using immunosuppressive drugs is significant, being associated with a higher incidence of cardiovascular incidents such as myocardial infarction and stroke. This paper analyzes the mechanisms of action of commonly used immunosuppressive drugs and their impact on the cardiovascular system. The adverse effect of immunosuppressive drugs is associated with toxicity within the cardiovascular system, which may be a problem in the clinical management of patients after transplantation. Immunosuppressants act on the cardiovascular system in a variety of ways, including fibrosis and myocardial remodeling, endothelium disfunction, hypertension, atherosclerosis, dyslipidemia or hyperglycaemia, metabolic syndrome, and hyperuricemia. The use of multidrug protocols makes it possible to develop regimens that can reduce the incidence of cardiovascular events. A better understanding of their mechanism of action and the range of complications could enable physicians to select the appropriate therapy for a given patient, as well as to reduce complications and prolong life.

Long Term Complications of Immunosuppression Post Liver Transplant

Improvement in immunosuppression has led to a remarkable improvement in short-term and long-term outcomes post-liver transplant (LT). However, with improvements in long-term survival, complications related to immunosuppressive drugs, either directly or indirectly, have also increased. The adverse events could be drug-specific, class-specific, or generic. Calcineurin inhibitors (cyclosporine and tacrolimus) are the backbone of the immunosuppression after LT and the main culprit associated with most of the complications, including renal failure, post-transplant diabetes mellitus (PTDM), and metabolic syndrome. Steroids are also implicated in the development of diabetes, osteoporosis, and metabolic syndrome post-LT. The development of infections and de novo malignancies (DNMs) is a generic effect linked to the overall cumulative immunosuppression. The development of these complications significantly hampers the quality of life and leads to increased morbidity and mortality post-LT. Thus, it is important to minimize the cumulative immunosuppression dose while simultaneously preventing allograft rejection. This review provides up-to-date, comprehensive knowledge of the complications of long-term immunosuppression post-LT along with associated risk factors and strategies to minimize the risk of complications.

Hyperglycemia and Hyperlipidemia with Kidney or Liver Transplantation: A Review

Although solid organ transplantation in persons with diabetes mellitus is often associated with hyperglycemia, the risk of hyperlipidemia in all organ transplant recipients is often underestimated. The diagnosis of diabetes often predates transplantation; however, in a moderate percentage of allograft recipients, perioperative hyperglycemia occurs triggered by antirejection regimens. Post-transplant prescription of glucocorticoids, calcineurin inhibitors and mTOR inhibitors are associated with increased lipid concentrations. The existence of diabetes mellitus prior to or following a liver transplant is associated with shorter times of useful allograft function. A cycle involving Smad, TGF beta, m-TOR and toll-like receptors has been identified in the contribution of rejection and aging of allografts. Glucocorticoids (prednisone) and calcineurin inhibitors (cyclosporine and tacrolimus) induce hyperglycemia associated with insulin resistance. Azathioprine, mycophenolate and prednisone are associated with lipogenesis. mTOR inhibitors (rapamycin) are used to decrease doses of atherogenic agents used for immunosuppression. Post-transplant medication management must balance immune suppression and glucose and lipid control. Concerns regarding rejection often override those relative to systemic and organ vascular aging and survival. This review focuses attention on the underlying mechanism of relationships between glycemia/lipidemia control, transplant rejection and graft aging.

Role of cyclosporin A in the treatment of kidney disease and nephrotoxicity

The clinical use of cyclosporin A (CsA) has led to significant advances and achievements in the field of transplantation and immune diseases. However, the nephrotoxicity of CsA is a major concern in current immunosuppression regimens. CsA causes abnormal kidney function while treating kidney disease, causing problems for clinicians and patients. Evidence of CsA nephrotoxicity is almost always present in transplant recipients after long-term CsA administration (up to 10 years), and similar phenomena occur with other calcineurin inhibitors. In this review, we summarize the mechanisms and influencing factors of CsA for the treatment of primary nephrotic syndrome. The mechanisms of CsA nephrotoxicity, clinical-pathological features, diagnosis, prevention strategies, and risk factors are summarized. We discuss the correlates and mechanisms of the switch between kidney disease prevention and nephrotoxicity of CsA to better understand the function of CsA in the kidney and to provide a basis for the prevention and treatment of CsA nephrotoxicity.

The case for the therapeutic use of mechanistic/mammalian target of rapamycin (mTOR) inhibitors in xenotransplantation

The mechanistic/mammalian target of rapamycin (mTOR) is one of the systems that are necessary to maintain cell homeostasis, such as survival, proliferation, and differentiation. mTOR inhibitors (mTOR-Is) are utilized as immunosuppressants and anti-cancer drugs. In organ allotransplantation, current regimens infrequently include an mTOR-I, which are positioned more commonly as alternative immunosuppressants. In clinical allotransplantation, long-term efficacy has been established, but there is a significant incidence of adverse events, for example, inhibition of wound healing, buccal ulceration, anemia, hyperglycemia, dyslipidemia, and thrombocytopenia, some of which are dose-dependent. mTOR-Is have properties that may be especially beneficial in xenotransplantation. These include suppression of T cell proliferation, increases in the number of T regulatory cells, inhibition of pig graft growth, and anti-inflammatory, anti-viral, and anti-cancer effects. We here review the potential benefits and risks of mTOR-Is in xenotransplantation and suggest that the benefits exceed the adverse effects.

Training vs. Tolerance: The Yin/Yang of the Innate Immune System

For almost nearly a century, memory functions have been attributed only to acquired immune cells. Lately, this paradigm has been challenged by an increasing number of studies revealing that innate immune cells are capable of exhibiting memory-like features resulting in increased responsiveness to subsequent challenges, a process known as trained immunity (known also as innate memory). In contrast, the refractory state of endotoxin tolerance has been defined as an immunosuppressive state of myeloid cells portrayed by a significant reduction in the inflammatory capacity. Both training as well tolerance as adaptive features are reported to be accompanied by epigenetic and metabolic alterations occurring in cells. While training conveys proper protection against secondary infections, the induction of endotoxin tolerance promotes repairing mechanisms in the cells. Consequently, the inappropriate induction of these adaptive cues may trigger maladaptive effects, promoting an increased susceptibility to secondary infections-tolerance, or contribute to the progression of the inflammatory disorder-trained immunity. This review aims at the discussion of these opposing manners of innate immune and non-immune cells, describing the molecular, metabolic and epigenetic mechanisms involved and interpreting the clinical implications in various inflammatory pathologies.

The Role of Preoperative Chronic Statin Therapy in Heart Transplant Receipts-A Retrospective Single-Center Cohort Study

BACKGROUND

Statin therapy has been proven to reduce the risk of cardiovascular events. The objective of our retrospective study was to investigate the relationship between preoperative chronic administration of statins to postoperative 2-month heart transplantation complications.

METHODS

A total number of 38 heart transplantation recipients from the Cardiovascular and Transplant Emergency Institute of Târgu Mureș between May 2014 and January 2021 were included in our study.

RESULTS

In logistic regression, we found a statistical significance between statin treatment and the presence of postoperative complications of any cause (OR: 0.06, 95% CI: 0.008-0.56; p = 0.0128), simultaneously presenting an elevated risk for early-postoperative acute kidney injury (AKI). From the statin group, atorvastatin therapy had a higher risk of type 2 diabetes mellitus (T2DM) development (OR: 29.73, 95% CI: 1.19-741.76; p = 0.0387) and AKI (OR: 29.73, 95% CI: 1.19-741.76; p = 0.0387). C-reactive protein (CRP), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) represented risk factors, atorvastatin administration being independently associated with lower CRP values.

CONCLUSIONS

Chronic previous administration of statins represented a protective factor to the development of 2-month postoperative complications of any cause in heart transplant receipts.

A GMP Protocol for the Manufacture of Tregs for Clinical Application

Infusion of regulatory T cells is a promising therapeutic strategy in organ transplantation to modulate the immune system, prevent rejection, minimize the need for pharmaceutical immunosuppression, and improve long-term transplant outcomes. Here we describe a GMP-compliant method we have used for the manufacture of ex vivo expanded autologous regulatory T cells for use in clinical trials.

Nutrition Disturbances and Metabolic Complications in Kidney Transplant Recipients: Etiology, Methods of Assessment and Prevention-A Review

Nutrition disturbances occur at all stages of chronic kidney disease and progress with the decrease of the kidney filtration rate. Kidney transplantation (KTx) as the best form of kidney replacement therapy poses various nutritional challenges. Prior to transplantation, recipients often present with mild to advanced nutrition disturbances. A functioning allograft not only relieves uremia, acidosis, and electrolyte disturbances, but also resumes other kidney functions such as erythropoietin production and vitamin D3 metabolism. KTx recipients represent a whole spectrum of undernutrition and obesity. Since following transplantation, patients are relieved of most dietary restrictions and appetite disturbances; they resume old nutrition habits that result in weight gain. The immunosuppressive regimen often predisposes them to dyslipidemia, glucose intolerance, and hypertension. Moreover, most recipients present with chronic kidney graft disease at long-term follow-ups, usually in stages G2-G3T. Therefore, the nutritional status of KTx patients requires careful monitoring. Appropriate dietary and lifestyle habits prevent nutrition disturbances and may improve kidney graft function. Despite many nutritional guidelines and recommendations targeted at chronic kidney disease, there are few targeted at KTx recipients. We aimed to provide a brief review of nutrition disturbances and known nutritional recommendations for kidney transplant recipients based on the current literature and dietary trends.

PCSK9 Inhibitor: Safe Alternative to Fill the Treatment Gap in Statin-Limited Conditions?

Lipid-lowering therapy is of great importance in reducing the burden of atherosclerotic cardiovascular disease. Statins act as first-line therapy in the current lipid management guidelines. However, statin use is limited in (1) statin-induced adverse events, including statin-associated muscle symptoms, new-onset diabetes mellitus, drug-induced liver injuries, acute kidney injuries, cognitive effects, hemorrhagic strokes, and cataracts; (2) special populations, including pregnant and lactating patients, patients with decompensated cirrhosis, and patients on dialysis; (3) coadministration with statin-interactive drugs, such as anti-human immunodeficiency virus drugs, anti-hepatitis C virus drugs, and immunosuppressive drugs. These considerable statin-limited groups are in urgent need of safer alternative lipid-lowering options. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are attracting widespread attention for their documented safety in general populations and superior lipid-lowering properties. Therefore, questions have been raised whether PCSK9 inhibitors could be a safe alternative in patients who are intolerant to statin therapy. In this review, we discuss the safety of PCSK9 inhibitors in statin-limited conditions. We conclude that PCSK9 inhibitors are a safe alternative lipid-lowering therapy in various statin-limited conditions. Furthermore, we identify several limitations in the current literature and suggest future directions, for the refinement of lipid management regimens.

Cardiovascular Risk after Kidney Transplantation: Causes and Current Approaches to a Relevant Burden

Background. Cardiovascular disease is a frequent complication after kidney transplantation and represents the leading cause of mortality in this population. Material and Methods. We searched for the relevant articles in the National Institutes of Health library of medicine, transplant, cardiologic and nephrological journals. Results. The pathogenesis of cardiovascular disease in kidney transplant is multifactorial. Apart from non-modifiable risk factors, such as age, gender, genetic predisposition and ethnicity, several traditional and non-traditional modifiable risk factors contribute to its development. Traditional factors, such as diabetes, hypertension and dyslipidemia, may be present before and may worsen after transplantation. Immunosuppressants and impaired graft function may strongly influence the exacerbation of these comorbidities. However, in the last years, several studies showed that many other cardiovascular risk factors may be involved in kidney transplantation, including hyperuricemia, inflammation, low klotho and elevated Fibroblast Growth Factor 23 levels, deficient levels of vitamin D, vascular calcifications, anemia and poor physical activity and quality of life. Conclusions. The timely and effective treatment of time-honored and recently discovered modifiable risk factors represent the basis of the prevention of cardiovascular complications in kidney transplantation. Reduction of cardiovascular risk can improve the life expectancy, the quality of life and the allograft function and survival.

Dyslipidemia in Transplant Patients: Which Therapy?

Cardiovascular disease is the most important cause of death worldwide in recent years; an increasing trend is also shown in organ transplant patients subjected to immunosuppressive therapies, in which cardiovascular diseases represent one of the most frequent causes of long-term mortality. This is also linked to immunosuppressant-induced dyslipidemia, which occurs in 27 to 71% of organ transplant recipients. The aim of this review is to clarify the pathophysiological mechanisms underlying dyslipidemia in patients treated with immunosuppressants to identify immunosuppressive therapies which do not cause dyslipidemia or therapeutic pathways effective in reducing hypercholesterolemia, hypertriglyceridemia, or both, without further adverse events.

Racial and ethnic disparities due to Medicare Part D Star Ratings criteria among kidney transplant patients with diabetes, hypertension, and/or dyslipidemia

BACKGROUND: Policies such as Medicare Part D Star Ratings are designed to encourage medication adherence and facilitate positive health outcomes. Patients who have received a kidney transplant not included in assessment of Star Ratings measures may have worse outcomes. OBJECTIVE: To determine if criteria for inclusion in assessment of Star Ratings medication adherence measures among kidney transplant patients with diabetes, hypertension, and dyslipidemia lead to racial and ethnic disparities in who is included in this assessment. METHODS: This was a cross-sectional, secondary analysis of 94,822 adult kidney transplant patients receiving continuous coverage of Medicare Parts A/B/D and filling at least 1 prescription for diabetes, hypertension, or dyslipidemia in 2017. Utilizing 2017 Medicare claims, inclusion in assessment of Star Ratings measures was determined based on criteria for each measure concerning adherence to oral diabetes, hypertension, and dyslipidemia medication. Binary and multinomial logistic regression were conducted. RESULTS: Among kidney transplant patients with diabetes only, Black and Hispanic patients were less likely than White patients to be included in assessment of the Star Ratings adherence measure for oral diabetes medications (P < 0.0001). Among kidney transplant patients with hypertension only and dyslipidemia only, all racial and ethnic minority groups were less likely to be included in assessments of Star Ratings adherence measures for oral hypertension and dyslipidemia medications (P < 0.001). For example, among patients with hypertension, adjusted odds ratios for inclusion of Black, Hispanic, and Asian patients were 0.44 (95% CI = 0.40-0.49), 0.56 (95% CI = 0.49-0.63), and 0.55 (95% = CI 0.45-0.67), respectively. CONCLUSIONS: Disparities exist among patients who have received a kidney transplant qualifying for inclusion in Star Ratings measures, which may ultimately facilitate adverse health outcomes. DISCLOSURES: Marie Chisholm-Burns is a member of the American Society of Transplantation Board of Directors. Christina Spivey has no conflicts of interest to disclose. Chi Chun Tsang has no conflicts of interest to disclose. Junling Wang received funding for this project from the National Institute on Aging/National Institutes of Health; she has also received funding from AbbVie and Pharmaceutical Research and Manufacturers of America (additionally, she has received consulting fees from the latter). Research reported in this publication was supported by the National Institute on Aging of the National Institutes of Health under Award Number R01AG049696 (Principal Investigator: Junling Wang). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The sponsor of the research does not have any role in any aspect of the research, including study design and the collection, analysis, and interpretation of data; the writing of the report; and the decision to submit the manuscript for publication.

Is Liver Transplant Curative in Homozygous Familial Hypercholesterolemia? A Review of Nine Global Cases

INTRODUCTION

Homozygous familial hypercholesterolemia (HoFH) is a rare, life-threatening, inherited condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C). Patients are at high risk of atherosclerotic cardiovascular disease, adverse cardiovascular events, and associated early mortality. Liver transplant is sometimes used with curative intent. The objective of the current case series was to evaluate the follow-up of a range of patients who have undergone liver transplant for the treatment of HoFH.

METHODS

Patients with clinical and/or genetic diagnoses of HoFH were treated according to local practices in four units in Europe and the Middle East. All patients underwent liver transplantation. Baseline and long-term follow-up data were collected, including LDL-C levels, DNA mutations, lipid-lowering medications, and complications due to surgery and immunosuppressive therapy.

RESULTS

Nine patients were included with up to 22 years' follow-up (mean ± SD 11.7 ± 11.7 years; range 0.5-28 years). Three of the patients died as a result of complications of transplant surgery (mortality rate 33%). Among the surviving six patients, four required continued lipid-lowering therapy (LLT) to maintain LDL-C levels and two patients show signs of increasing LDL-C levels that require management. One case (11%) required two consecutive transplants to achieve a viable graft and is awaiting a third transplant because of graft failure.

CONCLUSIONS

Liver transplant did not enable attainment of recommended LDL-C targets in most patients with HoFH, and the majority of patients still required post-transplant LLT. Liver transplant was not curative in most of the patients with HoFH followed. Guidelines suggest that transplant is a treatment of last resort if contemporary treatments are not available or possible.

Dyslipidemia in Renal Transplant Recipients

Dyslipidemia is a frequent complication after kidney transplantation (KT) and is an important risk factor for cardiovascular disease (CVD). Renal transplant recipients (RTRs) are considered at high, or very high, risk of CVD, which is a leading cause of death in this patient group. Despite many factors of post-transplant dyslipidemia, the immunosuppressive treatment has the biggest influence on a lipid profile. There are no strict dyslipidemia treatment guidelines for RTRs, but the ones proposing an individual approach regarding CVD risk seem most suitable. Proper diet and physical activity are the main general measures to manage dyslipidemia and should be introduced initially in every patient after KT. In the case of an insufficient correction of lipemia, statins are the basis for hypolipidemic treatment. Statins should be introduced with caution to avoid serious side-effects (e.g., myopathy) or drug-drug interactions, especially with immunosuppressants. To lower the incidence of adverse effects, and improve medication adherence, ezetimibe in combination with statins is recommended. Fibrates and bile sequestrants are not recommended due to their side-effects and variable efficacy. However, several new lipid-lowering drugs like Proprotein convertase subtilisin/Kexin type9 (PCSK9) inhibitors may have promising effects in RTRs, but further research assessing efficacy and safety is yet to be carried out.

The Use of Machine Learning Algorithms and the Mass Spectrometry Lipidomic Profile of Serum for the Evaluation of Tacrolimus Exposure and Toxicity in Kidney Transplant Recipients

Tacrolimus has a narrow therapeutic window; a whole-blood trough target concentration of between 5 and 8 ng/mL is considered a safe level for stable kidney transplant recipients. Tacrolimus serum levels must be closely monitored to obtain a balance between maximizing efficacy and minimizing dose-related toxic effects. Currently, there is no specific tacrolimus toxicity biomarker except a graft biopsy. Our study aimed to identify specific serum metabolites correlated with tacrolinemia levels using serum high-precision liquid chromatography–mass spectrometry and standard laboratory evaluation. Three machine learning algorithms were used (Naïve Bayes, logistic regression, and Random Forest) in 19 patients with high tacrolinemia (8 ng/mL) and 23 patients with low tacrolinemia (5 ng/mL). Using a selected panel of five lipid metabolites (phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine, arachidyl palmitoleate, and ceramide), Mg2+, and uric acid, all three machine learning algorithms yielded excellent classification accuracies between the two groups. The highest classification accuracy was obtained by Naïve Bayes, with an area under the curve of 0.799 and a classification accuracy of 0.756. Our results show that using our identified five lipid metabolites combined with Mg2+ and uric acid serum levels may provide a novel tool for diagnosing tacrolimus toxicity in kidney transplant recipients. Further validation with targeted MS and biopsy-proven TAC toxicity is needed.

Prevention of Triglyceridemia by (Non-)Anticoagulant Heparin(oids) Does Not Preclude Transplant Vasculopathy and Glomerulosclerosis

Background: In renal transplantation, chronic transplant dysfunction (CTD) is associated with increased PCSK9 and dyslipidemia. PCSK9 is an enzyme that increases plasma cholesterol levels by downregulating LDLR expression. We recently showed increased PCSK9-syndecan-1 interaction in conditions of proteinuria and renal function loss. Treatment with heparin(oids) might be a therapeutic option to improve dyslipidemia and CTD. We investigated the effects of (non-)anticoagulant heparin(oids) on serum lipids, syndecan-1 and PCSK9 levels, and CTD development. Methods: Kidney allotransplantation was performed from female Dark Agouti to male Wistar Furth recipients. Transplanted rats received daily subcutaneous injections of saline, unfractionated heparin, and RO-heparin or NAc-heparin (2 mg heparin(oid)/kg BW) until sacrifice after 9 weeks of treatment. Results: Saline-treated recipients developed hypertension, proteinuria, and loss of creatinine clearance (all p < 0.05 compared to baseline), along with glomerulosclerosis and arterial neo-intima formation. Saline-treated recipients showed significant increase in plasma triglycerides (p < 0.05), borderline increase in non-HDLc/HDLc (p = 0.051), and ∼10-fold increase in serum syndecan-1 (p < 0.05), without significant increase in serum PCSK9 at 8 weeks compared to baseline. Heparin and non-anticoagulant RO-heparin administration in transplanted rats completely prevented an increase in triglycerides compared to saline-treated recipients at 8 weeks (both p < 0.05). Heparin(oids) treatment did not influence serum total cholesterol (TC), plasma syndecan-1 and PCSK9 levels, creatinine clearance, proteinuria, glomerulosclerosis, and arterial neo-intima formation, 8 weeks after transplantation. Combining all groups, increased syndecan-1 shedding was associated with TC (r = 0.5; p = 0.03) and glomerulosclerosis (r = 0.53; p = 0.021), whereas the non-HDLc/HDLc ratio was associated with the neo-intimal score in the transplanted kidneys (r = 0.65; p < 0.001). Conclusion: Prevention of triglyceridemia by (non-)anticoagulant heparin(oids) neither influenced PCSK9/syndecan-1 nor precluded CTD, which however did associate with the shedding of lipoprotein clearance receptor syndecan-1 and the unfavorable cholesterol profile.

Prevalence and Predictors of Insufficient Plasma Vitamin C in a Subtropical Region and Its Associations with Risk Factors of Cardiovascular Diseases: A Retrospective Cross-Sectional Study

Background: to evaluate the prevalence and predictors of insufficient plasma vitamin C among adults in a subtropical region and its associations with cardiovascular disease risk factors including dyslipidemia and lipid-independent markers, namely homocysteine, high-sensitivity C-reactive protein (hs-CRP) and lipoprotein(a). Methods: Data of this retrospective cross-sectional study were extracted from electronic medical database of a Medical Center. Based on plasma vitamin C status, subjects were split into two groups—subjects with sufficient and insufficient plasma vitamin C levels (<50 µmol/L, ≤8.8 mg/L). Results: Prevalence of insufficient plasma vitamin C in 3899 adults was 39%. Multivariate logistic regression identified male gender, high body mass index, age 20−39, and winter/spring as independent predictors of insufficient vitamin C among all subjects. Greater proportions of subjects with insufficient plasma vitamin C had lower high-density lipoprotein cholesterol levels and elevated levels of triglyceride, homocysteine and hs-CRP (all p < 0.001). There were no differences in total cholesterol, low-density lipoprotein cholesterol and lipoprotein(a) between groups. Conclusions: There was a high prevalence of insufficient plasma vitamin C in the subtropical region, which indicates that insufficient plasma vitamin C remains a public health issue. Further study is needed to confirm these findings and to determine the underlying mechanisms.

Management of long-term cardiovascular risk factors post organ transplant

PURPOSE OF REVIEW

Cardiovascular disease is one of the leading causes of death in solid organ transplant (SOT) recipients. Early identification of cardiovascular risk factors and their adequate management in this population is key for prevention and improved outcomes.

RECENT FINDINGS

Approximately 80% of SOT present one or more cardiovascular risk factors, with increasing prevalence with time posttransplantation. They are due to the interplay of pretransplant conditions and metabolic consequences of immunosuppressive agents, mainly corticosteroids and calcineurin inhibitors. Among the pharmacological management strategies, statins have shown an important protective effect in SOT.

SUMMARY

Strict surveillance of cardiovascular risk factors is recommended in SOT due to their high prevalence and prognostic implications. Further studies on the best managements strategies in this population are needed.

Nuclear Receptor PXR in Drug-Induced Hypercholesterolemia

Atherosclerosis is a major global health concern. The central modifiable risk factors and causative agents of the disease are high total and low-density lipoprotein (LDL) cholesterol. To reduce morbidity and mortality, a thorough understanding of the factors that influence an individual’s cholesterol status during the decades when the arteria-narrowing arteriosclerotic plaques are forming is critical. Several drugs are known to increase cholesterol levels; however, the mechanisms are poorly understood. Activation of pregnane X receptor (PXR), the major regulator of drug metabolism and molecular mediator of clinically significant drug–drug interactions, has been shown to induce hypercholesterolemia. As a major sensor of the chemical environment, PXR may in part mediate hypercholesterolemic effects of drug treatment. This review compiles the current knowledge of PXR in cholesterol homeostasis and discusses the role of PXR in drug-induced hypercholesterolemia.

Immunosuppression in Lung Transplantation

Immunosuppression in lung transplantation is an area devoid of robust clinical data. This chapter will review the history of immunosuppression in lung transplantation. Additionally, it will evaluate the three classes of induction, maintenance, and rescue immunosuppression in detail. Induction immunosuppression in lung transplantation aims to decrease incidence of lung allograft rejection, however infectious risk must be considered when determining if induction is appropriate and which agent is most favorable. Similar to other solid organ transplant patient populations, a multi-drug approach is commonly prescribed for maintenance immunosuppression to minimize single agent drug toxicities. Emphasis of this review is placed on key medication considerations including dosing, adverse effects, and drug interactions. Clinical considerations will be reviewed per drug class given available literature. Finally, acute cellular, antibody mediated, and chronic rejection are reviewed.

Management of the Failing Kidney Transplant: Challenges and Solutions

The kidneys are the most transplanted organs, and the number of failed kidney transplants that require reinstitution of renal replacement therapy in patients is on the increase. Increased mortality has been noted in patients with failed grafts compared with transplant- naïve patients with chronic kidney disease who are treated with dialysis. Issues such as management of immunosuppression, the need for transplant nephrectomy, addressing the increased risk of cardiovascular events, malignancies, and infections are debatable and often based on individual or hospital practices. The optimal timing and modality of renal replacement therapy to be reinitiated are sometimes blurred, with considerable variations among physician practices. Guidelines are therefore needed to appropriately manage this special population of patients with the aim of improving outcomes. Here, our objective was to review the current practices in managing patients with failing kidney transplants so that recommendations can be made based on the available evidence.

Treatment of Mixed Dyslipidemia With Alirocumab in a Kidney Transplant Recipient: A Case Report

Dyslipidemia is common in kidney transplant recipients owing to the disturbance of lipid metabolism caused by chronic kidney disease and the effect of immunosuppression on lipid metabolism. Patients receiving treatment with mammalian target of rapamycin inhibitors show more prominent lipid disorders, which are attributed mainly, but not only, to adipocyte lipid uptake disruption, lipolysis promotion and lipogenic gene expression enhancement. Dyslipidemias in kidney transplant recipients predispose these patients to an increased risk of developing cardiovascular disease; thus, current guidelines recommend treatment initiation with a statin, regardless of low-density lipoprotein cholesterol (LDL-C) concentration, with ezetimibe as a secondary option for patients who do not tolerate such therapy or for those with inadequate response. Treatment with pro-protein convertase subtilisin/kexin type 9 inhibitors such as alirocumab, although effectively reducing LDL-C in patients with chronic kidney disease, has not been evaluated in kidney transplant recipients. In this case report, we present a case of a female kidney transplant recipient who developed substantial dyslipidemia after everolimus initiation. This case was resistant to treatment with simvastatin/ezetimibe combination, and the patient subsequently received alirocumab. Our patient showed a mean reduction of 46.6% in LDL-C during an 18-month period after alirocumab initiation, which is comparable to the results of studies on patients with or without renal impairment. Furthermore, treatment with alirocumab proved to be well tolerated without adverse effects or interactions with the immunosuppression regimen.

Dyslipidemia in Chronic Kidney Disease: Contemporary Concepts and Future Therapeutic Perspectives

BACKGROUND

Chronic kidney disease (CKD) is an increasingly prevalent disease state met with great morbidity and mortality primarily resulting from the high incidence of adverse cardiovascular outcomes. Therapeutic strategies in this patient population aim at controlling modifiable cardiovascular risk factors, including dyslipidemia.

SUMMARY

In this review article, we first provide the latest pathophysiologic evidence regarding the altered dyslipidemia pattern in CKD, followed by its contemporary management according to the latest guidelines. Moreover, we present the current progress regarding the emerging therapeutic strategies. Key Messages: The presence of renal impairment leads to alterations in cholesterol structure, metabolism, and reverse transport paired with increased oxidative stress. Statins remain the cornerstone of dyslipidemia management in patients with kidney dysfunction who are at risk for cardiovascular events. However, their efficacy is debatable in end-stage renal disease under renal replacement therapy. Therefore, novel treatment approaches aiming at hypertriglyceridemia, proprotein convertase subtilisin/kexin type 9, and lipoprotein(a) are under rigorous investigation while the research of gut microbiome might provide additional mechanistic and therapeutic insight.

Non-HDL cholesterol is an independent predictor of long-term cardiovascular events in patients with dyslipidemia after renal transplantation

BACKGROUND

Posttransplant dyslipidemia is a common condition in renal transplantation recipients (RTR) and is related to poor cardiac outcomes. We aimed to demonstrate the value of non-high-density lipoprotein cholesterol (non-HDL-C) in predicting long-term major cardiovascular and cerebrovascular events (MACCE) in RTR with dyslipidemia.

METHODS

Patients who had undergone renal transplantation between 2011 and 2019 were retrospectively analysed and were classified as normal non-HDL-C and high non-HDL-C groups based on first year levels. Development of high non-HDL-C levels was used to predict the occurrence of MACCE (a combination of cardiac death, nonfatal myocardial infarction, unstable angina, and nonfatal stroke) and all-cause death during the long-term follow-up.

RESULTS

Overall, 674 patients were included, of whom 470 (69.7%) were male; the mean age was 43.6 ± 13.2 years. The mean follow-up duration was 5.5 ± 2.29 years 1 year after the transplant. MACCE occurred during the follow-up in 102 (61.8%) patients in the high non-HDL-C group and 13 (2.6%) patients in the normal non-HDL-C group (P < .001). High non-HDL-C was a predictor of MACCE in the multivariate analysis (hazard ratio [HR] 1.02, 95% confidence interval [CI] 1.01-1.02, P < .001). Smoking (HR: 1.92, 95% CI 1.16-3.20, P < .001), cadaver graft (HR: 2.55, 95% CI 1.52-4.26, P < .001), and left ventricular ejection fraction (HR: 0.96, 95% CI 0.94-0.98, P < .001) were also predictors of MACCE. Kaplan-Meier analysis revealed that all MACCE components and all-cause mortality were significantly higher in the high non-HDL-C group (P < .001).

CONCLUSION

Non-HDL-C was closely related to long-term cardiac outcomes in RTR with dyslipidemia. Non-HDL-C should be among the primary goals in lipid-lowering treatment in post-transplant dyslipidemia.

Managing cardiovascular disease risk in South Asian kidney transplant recipients

South Asians (SA) are at higher cardiovascular risk than other ethnic groups, and SA kidney transplant recipients (SA KTR) are no exception. SA KTR experience increased major adverse cardiovascular events both early and late post-transplantation. Cardiovascular risk management should therefore begin well before transplantation. SA candidates may require aggressive screening for pre-transplant cardiovascular disease (CVD) due to their ethnicity and comorbidities. Recording SA ethnicity during the pre-transplant evaluation may enable programs to better assess cardiovascular risk, thus allowing for earlier targeted peri- and post-transplant intervention to improve cardiovascular outcomes. Diabetes remains the most prominent post-transplant cardiovascular risk factor in SA KTR. Diabetes also clusters with other metabolic syndrome components including lower high-density lipoprotein cholesterol, higher triglycerides, hypertension, and central obesity in this population. Dyslipidemia, metabolic syndrome, and obesity are all significant CVD risk factors in SA KTR, and contribute to increased insulin resistance. Novel biomarkers such as adiponectin, apolipoprotein B, and lipoprotein (a) may be especially important to study in SA KTR. Focused interventions to improve health behaviors involving diet and exercise may especially benefit SA KTR. However, there are few interventional clinical trials specific to the SA population, and none are specific to SA KTR. In all cases, understanding the nuances of managing SA KTR as a distinct post-transplant group, while still screening for and managing each CVD risk factor individually in all patients may help improve the long-term success of all kidney transplant programs catering to multi-ethnic populations.

Fecal Metabolomics Reveals Distinct Profiles of Kidney Transplant Recipients and Healthy Controls

Monitoring graft recipients remains dependent on traditional biomarkers and old technologies lacking specificity, sensitivity, or accuracy. Recently, metabolomics is becoming a promising approach that may offer to kidney transplants a more effective and specific monitoring. Furthermore, emerging evidence suggested a fundamental role of gut microbiota as an important determinant of patients’ metabolomes. In the current study, we enrolled forty stable renal allografts recipients compared to twenty healthy individuals. Samples were taken at different time points from patient to patient following transplantation surgery, which varied from 3 months to 22 years post-graft. All patients started the immunosuppression therapy immediately following kidney graft (Day 0). Gas chromatography–mass spectrometry (GC–MS) was employed to perform untargeted analysis of fecal metabolites. Globally, the fecal metabolic signature was significantly different between kidney transplants and the control group. Fecal metabolome was dominated by lipids (sterols and fatty acids) in the stable transplant group compared to the controls (p < 0.05). Overall, 18 metabolites were significantly altered within kidney transplant recipients. Furthermore, the most notable altered metabolic pathways in kidney transplants include ubiquinone and other terpenoid-quinone biosynthesis, tyrosine metabolism, tryptophan biosynthesis, and primary bile acid biosynthesis. Fecal metabolites could effectively distinguish stable transplant recipients from controls, supporting the potential utility of metabolomics in rapid and non-invasive diagnosis to produce relevant biomarkers and to help clinicians in monitoring kidney transplants. Further investigations are needed to clarify the physiological relevance of fecal metabolome and to assess the impact of microbiota modulation.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Long-term Management of the Adult Liver Transplantation Recipients

The survival of liver transplantation (LT) recipients has been improved remarkably in short-term. The major causes of mortality in long-term include nonimmunological causes such as cardiovascular, de novo malignancy, chronic kidney disease, and recurrence of primary disease. Rejection-related mortality is rare in the long-term after LT. We discuss nonrejection causes of long-term morbidity/mortality, risk factors, and management strategies in LT recipients. In addition, we discuss osteoporosis, contraception, and pregnancy in LT recipients.

Glucose tolerance in a cohort of Egyptian children after kidney transplantation

BACKGROUND

Post- transplantation diabetes mellitus (PTDM) in children is a serious metabolic complication that can endanger both graft and patient survival. These complications can be partially reduced by early diagnosis & prompt treatment of impaired glucose tolerance. The aim of this study was to assess glucose tolerance & insulin resistance among a cohort of kidney transplanted children.

METHODS

Thirty consecutive pediatric kidney transplant recipients were subjected to basal evaluation of plasma glucose and insulin then underwent oral glucose tolerance test (OGTT).

RESULTS

Abnormal glucose metabolism was detected in 7 (23.3%) patients; 3 (10%) patients with PTDM; 3 (10%) patients with impaired fasting glucose (IFG) and 1 (3.3%) patient with IFG and impaired glucose tolerance (IGT). Four (13.3%) patients had high Homeostatic model assessment of insulin resistance (HOMA-IR). Patients with abnormal glucose metabolism had significantly higher tacrolimus trough levels and higher maintainence steroid doses (p values = 0.003,0.026). Significant positive correlation existed between pre-transplantation glucose level and post-transplantation fasting glucose (p = 0.001, r = 0.69), glucose at 120 min (p = 0.018, r = 0.429) and HOMA-IR (p = 0.008, r = 0.47).

CONCLUSION

Abnormalities in glucose metabolism (IFG, IGT &PTDM) are frequent in Egyptian pediatric kidney transplant recipients. OGTT is the gold standard for assessment of abnormalities in glucose metabolism.