Posttransplant metabolic syndrome

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.

Metabolic-Dysfunction-Associated Steatotic Liver Disease (MASLD) after Liver Transplantation: A Narrative Review of an Emerging Issue

The development of steatotic liver disease after liver transplant (LT) is widely described, and epidemiological data have revealed an increased incidence in recent times. Its evolution runs from simple steatosis to steatohepatitis and, in a small proportion of patients, to significant fibrosis and cirrhosis. Apparently, post-LT steatotic disease has no impact on the recipient's overall survival; however, a higher cardiovascular and malignancy burden has been reported. Many donors' and recipients' risk factors have been associated with this occurrence, although the recipient-related ones seem of greater impact. Particularly, pre- and post-LT metabolic alterations are strictly associated with steatotic graft disease, sharing common pathophysiologic mechanisms that converge on insulin resistance. Other relevant risk factors include genetic variants, sex, age, baseline liver diseases, and immunosuppressive drugs. Diagnostic evaluation relies on liver biopsy, although non-invasive methods are being increasingly used to detect and monitor both steatosis and fibrosis stages. Management requires a multifaceted approach focusing on lifestyle modifications, the optimization of immunosuppressive therapy, and the management of metabolic complications. This review aims to synthesize the current knowledge of post-LT steatotic liver disease, focusing on the recent definition of metabolic-dysfunction-associated steatotic liver disease (MASLD) and its metabolic and multisystemic concerns.

De novo metabolic syndrome after liver transplantation: a meta-analysis on cumulative incidence, risk factors, and outcomes

Post-transplant metabolic syndrome (PTMS) has been associated with increased cardiovascular risk which significantly impacts the morbidity and mortality rates of liver transplant (LT) recipients. This study sought to conduct a meta-analysis and systematic review on the cumulative incidence, risk factors, and cardiovascular outcomes associated with de novo PTMS.Medline and Embase were searched for articles describing the incidence, risk factors, and cardiovascular outcomes of de novo PTMS. Meta-analysis of proportions was conducted to calculate incidence. Conventional pairwise analysis using random effects model was used to tabulate OR and hazard ratio for risk factors and cardiovascular outcomes, respectively. Fifteen studies involving 2683 LT recipients were included. Overall rate of de novo PTMS was 24.7% (CI: 18.0%-32.9%) over a mean follow-up period of 15.3 months and was highest in patients with NAFLD (60.0%, CI: 52.0%-67.5%) compared with other liver diseases. Older age (OR: 1.05, CI: 1.01-1.09, p = 0.02) and pre-LT type II diabetes mellitus (OR: 5.00, CI: 4.17-5.99, p < 0.01) were predictive factors of de novo PTMS. Patients with de novo PTMS had significantly higher likelihood of cardiovascular disease events compared with those who did not (hazard ratio: 2.42, CI: 1.54-3.81, p < 0.01). De novo PTMS is a common complication and is significantly associated with increased cardiovascular disease morbidity. High-risk patients such as elderly recipients, those with pre-LT type II diabetes mellitus, or NASH-related cirrhosis should undergo routine screening to allow timely intervention.

Inevitability of disease recurrence after liver transplantation for NAFLD cirrhosis

Background & Aims

Liver transplantation (LT) is the only available treatment for end-stage non-alcoholic fatty liver disease (NAFLD) (related decompensated cirrhosis and/or hepatocellular carcinoma). The aim of our study was to evaluate the risk of disease recurrence after LT and the factors influencing it.

Method

This retrospective multicenter study included adults transplanted for NAFLD cirrhosis between 2000 and 2019 in 20 participating French-speaking centers. Disease recurrence (steatosis, steatohepatitis and fibrosis) was diagnosed from liver graft biopsies.

Results

We analyzed 150 patients with at least one graft liver biopsy available ≥6 months after transplantation, among 361 patients transplanted for NAFLD. The median (IQR) age at LT was 61.3 (54.4-64.6) years. The median follow-up after LT was 4.7 (2.8-8.1) years. The cumulative recurrence rates of steatosis and steatohepatitis at 5 years were 80.0% and 60.3%, respectively. Significant risk factors for steatohepatitis recurrence in multivariate analysis were recipient age at LT <65 years (odds ratio [OR] 4.214; p = 0.044), high-density lipoprotein-cholesterol <1.15 mmol/L after LT (OR 3.463; p = 0.013) and grade ≥2 steatosis on the graft at 1 year after LT (OR 10.196; p = 0.001). The cumulative incidence of advanced fibrosis (F3-F4) was 20.0% at 5 years after LT and significant risk factors from multivariate analysis were metabolic syndrome before LT (OR 8.550; p = 0.038), long-term use of cyclosporine (OR 11.388; p = 0.031) and grade ≥2 steatosis at 1 year after LT (OR 10.720; p = 0.049). No re-LT was performed for NAFLD cirrhosis recurrence.

Conclusion

Our results strongly suggest that recurrence of initial disease after LT for NAFLD is inevitable and progressive in a large proportion of patients; the means to prevent it remain to be further evaluated.

Impact and implications

Non-alcoholic fatty liver disease (NAFLD) is a growing indication for liver transplantation, but the analysis of disease recurrence, based on graft liver biopsies, has been poorly studied. Cumulative incidences of steatosis, steatohepatitis and NAFLD-related significant fibrosis recurrence at 5 years were 85.0%, 60.3% and 48.0%, respectively. Grade ≥2 steatosis on graft biopsy at 1 year (present in 25% of patients) is highly predictive of recurrence of steatohepatitis and advanced fibrosis: bariatric surgery should be discussed in these patients specifically.

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.

Enteric dysbiosis in liver and kidney transplant recipients: a systematic review

Several factors mediate intestinal microbiome (IM) alterations in transplant recipients, including immunosuppressive (IS) and antimicrobial drugs. Studies on the structure and function of the IM in the post-transplant scenario and its role in the development of metabolic abnormalities, infection, and cancer are limited. We conducted a systematic review to study the taxonomic changes in liver (LT) and kidney (KT) transplantation, and their potential contribution to post-transplant complications. The review also includes pre-transplant taxa, which may play a critical role in microbial alterations post-transplant. Two reviewers independently screened articles, and assessed risk of bias. The review identified 13 clinical studies, which focused on adult kidney and liver transplant recipients. Patient characteristics and methodologies varied widely between studies. Ten studies reported increased an abundance of opportunistic pathogens (Enterobacteriaceae, Enterococcaceae, Fusobacteriaceae, and Streptococcaceae) followed by butyrate-producing bacteria (Lachnospiraceae and Ruminococcaceae) in nine studies in post-transplant conditions. The current evidence is mostly based on observational data and studies with no proof of causality. Therefore, further studies exploring the bacterial gene functions rather than taxonomic changes alone are in demand to better understand the potential contribution of the IM in post-transplant complications.

Clinical considerations in the management of non-alcoholic steatohepatitis cirrhosis pre- and post-transplant: A multi-system challenge

Non-alcoholic steatohepatitis (NASH) is the most common chronic liver disease worldwide, and the fastest growing indication for liver transplantation in the United States. NASH is now the leading etiology for liver transplantation in women, the second leading indication for men, and the most common cause amongst recipients aged 65 years and older. Patients with end-stage liver disease related to NASH represent a unique and challenging patient population due the high incidence of associated comorbid diseases, including obesity, type 2 diabetes (T2D), and hypertension. These challenges manifest in the pre-liver transplantation period with increased waitlist times and waitlist mortality. Furthermore, these patients carry considerable risk of morbidity and mortality both before after liver transplantation, with high rates of T2D, cardiovascular disease, chronic kidney disease, poor nutrition, and disease recurrence. Successful transplantation for these patients requires identification and management of their comorbidities in the face of liver failure. Multidisciplinary evaluations include a thorough pre-transplant workup with a complete cardiac evaluation, control of diabetes, nutritional support, and even, potentially, consultation with a bariatric surgeon. This article provides a comprehensive review of the conditions and challenges facing patients with NASH cirrhosis undergoing liver transplantation and provides recommendations for evaluation and management to optimize them before liver transplantation to produce successful outcomes.

Long-term Outcomes in Patients Undergoing Liver Transplantation for Nonalcoholic Steatohepatitis-Related Cirrhosis

BACKGROUND

Nonalcoholic steatohepatitis (NASH), a clinically aggressive variant of nonalcoholic fatty liver disease (NAFLD), is becoming an increasingly common indication for liver transplantation (LT); however, relatively little is known regarding its clinical course post-LT. The aim of the current study is to describe disease recurrence and clinical course after LT.

METHODS

All surviving patients transplanted for NASH at the authors' institution had transient elastography (TE) to evaluate hepatic steatosis and fibrosis. The charts of deceased patients were reviewed for liver biopsy to evaluate for disease recurrence. Finally, causes of mortality in these patients were evaluated.

RESULTS

Of the 103 patients who met criteria, 56 had TE, whereas 34 had a liver biopsy. Steatosis was detected in 49 (87.5%) of the patients who had a TE and were defined to have recurrent NAFLD. Most patients had liver stiffness measurements consistent with no fibrosis (42.9%) or F1-F2 fibrosis (30.4%). Advanced fibrosis was noted in 26.8%, whereas 5.4% had cirrhosis but were clinically compensated. In patients with liver biopsy, 88.2% had recurrent NAFLD, whereas 41.2% had recurrent NASH. Bridging fibrosis was noted in 20.6% of patients but no patients had cirrhosis. Within the cohort, 32 patients died with the leading cause of mortality cancer (25%), infectious complications (25%), and cardiovascular disease (21.9%). Only 9% of deaths were attributable to graft cirrhosis.

CONCLUSIONS

Recurrent NAFLD is common post-LT occurring in nearly 88% of all patients, whereas nearly a quarter of patients were noted to have advanced fibrosis.

Metabolic syndrome and non-alcoholic fatty liver disease after liver or kidney transplantation

Transplantation is a definitive treatment option for patients with end-stage liver disease, and for some patients with acute liver failure, hepatocellular carcinoma or end-stage renal disease. Long-term post-transplantation complications have become an important medical issue, and cardiovascular diseases (CVD) are now the leading cause of mortality in liver or kidney transplant recipients. The increased prevalence of metabolic syndrome (MS) likely plays a role in the high incidence of post-transplantation CVD. MS and its hepatic manifestation, non-alcoholic fatty liver disease (NAFLD), are prevalent among the general population and in pre- and post-transplantation settings. MS components are associated with recurrent or de novo NAFLD in transplant recipients, potentially influencing post-transplantation survival. Moreover, recent data reveal an important association between NAFLD and risk of incident of chronic kidney disease (CKD). Therefore, NAFLD identification could represent an additional clinical feature for improving the stratification of liver and kidney transplant recipients with regards to risks of CVD, CKD and renal allograft dysfunction. All MS components are potentially modifiable; therefore, it is crucial that hepatologists, nephrologists and primary care physicians become more engaged in managing post-transplantation metabolic complications. The present review discusses the recent clinical evidence regarding the importance of MS and its components after liver and kidney transplantation, as well as the link between MS and NAFLD after liver and kidney transplantation.

Liver Transplantation for Alcoholic and Nonalcoholic Fatty Liver Disease: Pretransplant Selection and Posttransplant Management

Alcoholic fatty liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are common causes of chronic liver disease throughout the world. Although they have similar histologic features, a diagnosis of NAFLD requires the absence of significant alcohol use. ALD is seen commonly in patients with a long-standing history of excessive alcohol use, whereas NAFLD is encountered commonly in patients who have developed complications of obesity, such as insulin resistance, hypertension, and dyslipidemia. Lifestyle contributes to the development and progression of both diseases. Although alcohol abstinence can cause regression of ALD, and weight loss can cause regression of NAFLD, many patients with these diseases develop cirrhosis. ALD and NAFLD account for nearly 30% of liver transplants performed in the United States. Patients receiving liver transplants for ALD or NAFLD have similar survival times as patients receiving transplants for other liver disorders. Although ALD and NAFLD recur frequently after liver transplantation, graft loss from disease recurrence after transplantation is uncommon. Cardiovascular disease and de novo malignancy are leading causes of long-term mortality in liver transplant recipients with ALD or NAFLD.

Management of immunosuppressant agents following liver transplantation: Less is more

Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.

Endocrine causes of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. The prevalence of NAFLD is increasing, becoming a substantial public health burden. NAFLD includes a broad spectrum of disorders, from simple conditions such as steatosis to severe manifestations such as fibrosis and cirrhosis. The relationship of NAFLD with metabolic alterations such as type 2 diabetes is well described and related to insulin resistance, with NAFLD being recognized as the hepatic manifestation of metabolic syndrome. However, NAFLD may also coincide with endocrine diseases such as polycystic ovary syndrome, hypothyroidism, growth hormone deficiency or hypercortisolism. It is therefore essential to remember, when discovering altered liver enzymes or hepatic steatosis on radiological exams, that endocrine diseases can cause NAFLD. Indeed, the overall prognosis of NAFLD may be modified by treatment of the underlying endocrine pathology. In this review, we will discuss endocrine diseases that can cause NALFD. Underlying pathophysiological mechanisms will be presented and specific treatments will be reviewed.

Non-alcoholic fatty liver disease following liver transplantation: a clinical review

Non-alcoholic steatohepatitis (NASH) is rapidly becoming the leading indication for liver transplantation (LT) in the United States. While post-transplantation outcomes are similar to other indications for transplant, recent evidence has suggested that reduction in risk factors for post-transplant metabolic syndrome may impose a significant survival benefit in this patient population. Cardiovascular mortality is the leading cause of death following transplantation for NASH. While pre-transplant pharmacologic and surgical approaches have been utilized to reduce cardiovascular risk factors following transplantation, the effectiveness of these treatment approaches in the post-transplant setting is poorly defined. Studies are urgently needed in the treatment of this rapidly growing population.

Non-alcoholic fatty liver disease: a diabetologist's perspective

In the recent years, non-alcoholic fatty liver disease (NAFLD) has emerged as the commonest cause of chronic liver disease in the developed world. The global epidemic of obesity secondary to physical inactivity and adverse food habits accounts for the alarming rise in NAFLD. Metabolic syndrome plays a major role in the pathogenesis of both NAFLD and type 2 diabetes mellitus (T2DM). Whilst most cases of NAFLD remain asymptomatic with only hepatic steatosis, about 30 % progress to non-alcoholic steatohepatitis with chronic liver inflammation that can lead on to fibrosis, cirrhosis, liver failure, and hepatocellular carcinoma. Because of the similar pathogenesis shared between T2DM and NAFLD, T2DM occurs as an important complication in many cases of NAFLD, and many cases of T2DM are further complicated by NAFLD. Rapid progression and increased complications of the individual diseases is the end result of this dual coexistence. Diagnosis of NAFLD relies upon hepatic imaging, serum biochemical markers, and liver biopsy. As in T2DM, the most important management option for patients with NAFLD is lifestyle changes targeted at weight reduction. Other treatment options include insulin sensitizers (metformin and pioglitazone), vitamin E, incretin mimetics, omega-3 fatty acids, cholesterol lowering agents, orlistat, and bariatric surgery. The clinical spectrum, patho-physiological features and therapeutic options of NAFLD share many things in common with T2DM and therefore, this review is to highlight the diabetologist's perspective of the disease.