Metabolic Consequences of Solid Organ Transplantation

Harnessing Tumor Cell-Derived Exosomes for Immune Rejection Management in Corneal Transplantation

Transplantation remains the definitive treatment for end-stage organ failures, but its efficacy is frequently compromised by immune rejection. This study introduces a novel strategy by utilizing tumor-derived exosomes from B16-F10 melanoma cells (B16-Exo), diverging from the conventional use of immune cell-derived exosomes, to alleviate post-transplantation immune rejection. Utilizing murine corneal transplantation as a model, it is demonstrated that B16-Exo significantly reduces immune rejection, evidenced by decreased corneal opacity, neovascularization, and immune dysregulation, while enhancing postoperative survival. Proteomic analyses reveal differential expression of pivotal proteins in B16-Exo, notably the JAK2 protein within the JAK-STAT signaling pathway, which has been mechanistically demonstrated to amplify the activity of myeloid-derived suppressor cells (MDSCs) and inhibit T cell proliferation. These findings demonstrate the significant immunomodulatory effect of B16-Exo in transplant immunology, supporting the continued exploration of tumor-derived exosomes as a platform to uncover novel immunosuppressive mechanisms in transplantation.

Risk Factors for Early Post-transplant Weight Changes Among Simultaneous Pancreas-kidney Recipients and Impact on Outcomes

Background

There are limited data about the risk factors for weight changes and the association of significant weight changes with graft and metabolic outcomes after simultaneous pancreas and kidney (SPK) transplantation.

Methods

We included all SPK recipients with both allografts functioning for at least 6 mo post-transplant and categorized them based on the weight changes from baseline to 6 mo post-transplant. We analyzed risk factors for significant weight gain (SWG) and significant weight loss (SWL) over 6 mo post-transplant, as well as outcomes including pancreas uncensored graft failure, pancreas death-censored graft failure (DCGF), composite pancreas graft outcomes of DCGF, use of an antidiabetic agent, or hemoglobin A1C >6.5%, and kidney DCGF.

Results

Of 280 SPK recipients, 153 (55%) experienced no significant weight change, 57 (20%) SWG, and 70 (25%) SWL. At 6 mo post-transplant, mean weight changes were 1.2% gain in the no significant weight change group, 13.4% gain in SWG, and 9.6% loss in the SWL groups. In multivariate analysis, the only factor associated with decreased risk for weight gain was older recipient age (aOR, 0.97; 95% confidence intervals, 0.95-0.99). Importantly, SWG or SWL were not associated with pancreas graft failure, P-DCGF, or K-DCGF. Interestingly in the adjusted model, SWG at 6 mo was associated with a lower risk for composite outcomes (HR, 0.35; 95% confidence intervals, 0.14-0.85).

Conclusions

Forty-five percent of SPK recipients had significant weight changes by 6 mo post-transplant, but only 20% exhibited SWG. Likely because of proper management, weight changes were not associated with poor outcomes post-SPK transplant.

Anti-Obesity Medications in Patients With Heart Failure: Current Evidence and Practical Guidance

Obesity is a significant risk factor for heart failure (HF) development, particularly HF with preserved ejection fraction and as a result, many patients with HF also have obesity. There is growing clinical interest in optimizing strategies for the management of obesity in patients with HF across the spectrums of both ejection fraction and disease severity. The emergence of anti-obesity medications with cardiovascular outcomes benefits, principally glucagon-like peptide-1 receptor agonists, has made it possible to study the impact of anti-obesity medications for patients with baseline cardiovascular conditions, including HF. However, clinical trials data supporting the safety and efficacy of treating obesity in patients with HF is currently limited to patients with HF with preserved ejection fraction, but do confirm safety and weight loss efficacy in this patient population as well as improvements in HF functional status, biomarkers of inflammation and HF stability. Here, we review the current data available surrounding the management of obesity for patients with HF, including the limitations of this evidence and ongoing areas for investigation, summarize the next phase of emerging anti-obesity medications and provide practical clinical advice for the multidisciplinary management of patients with both HF and obesity.

An Artificial Intelligence-Based Digital Analysis of Immunolocalization of MMP2 and TIMP2 in the Jejunum of Rats Treated with Calcineurin Inhibitors

(1) Background: The main goal of this study was to analyze the morphology of the rat's jejunum after long-term treatment with calcineurin inhibitor-based immunosuppressive drugs and to investigate their impact on the location of MMP-2 and its inhibitor TIMP-2, as well as the balance between them. (2) Methods: Twenty-four rats were divided into four groups receiving different immunosuppressive regiments. After six months of treatment, the jejunums were collected and analyzed. (3) Results: immunosuppressive drug panels containing calcineurin inhibitors (CNIs) have a negative impact on the morphology and morphometry of the small intestinal wall. These drugs disrupt the MMP-2/TIMP-2 balance. Both CsA and TAC interfere with the synthesis of intercellular matrix components in the connective tissue of the small intestine. Furthermore, tacrolimus appears to disrupt the MMP-2/TIMP-2 balance in the small intestine the most, as the results show the highest difference between MMP-2 and TIMP-2 expression. The results were also confirmed by digital analysis of tissue segmentation. (4) Conclusions: The research conducted in this study is unique because there is limited information available on the direct effects of immunosuppressive drugs on the expression of MMP-2 and their inhibitors in the jejunum. Additionally, this study involves three drugs instead of one, which accurately reflects the panel of drugs used in organ recipients. Our results suggest that immunosuppressive drugs affect morphology and MMP2/TIMP2 immunoexpression; however, further studies are required. AI-based tools provide a reliable analysis of tissue samples, which represents an exciting approach for future histopathological studies. However, the results of the analyses generated by these tools need to be verified by specialists.

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.

Minimizing Metabolic and Cardiac Risk Factors to Maximize Outcomes After Liver Transplantation

Cardiovascular disease (CVD) is a leading complication after liver transplantation and has a significant impact on patients' outcomes posttransplant. The major risk factors for post-liver transplant CVD are age, preexisting CVD, nonalcoholic fatty liver disease, chronic kidney disease, and metabolic syndrome. This review explores the contemporary strategies and approaches to minimizing cardiometabolic disease burden in liver transplant recipients. We highlight areas for potential intervention to reduce the mortality of patients with metabolic syndrome and CVD after liver transplantation.

Chronic kidney disease combined with metabolic syndrome is a non-negligible risk factor

Metabolic syndrome (MetS) is a group of conditions characterized by hypertension (HTN), hyperglycaemia or insulin resistance (IR), hyperlipidaemia, and abdominal obesity. MetS is associated with a high incidence of cardiovascular events and mortality and is an independent risk factor for chronic kidney disease (CKD). MetS can cause CKD or accelerate the progression of kidney disease. Recent studies have found that MetS and kidney disease have a cause-and-effect relationship. Patients with CKD, those undergoing kidney transplantation, or kidney donors have a significantly higher risk of developing MetS than normal people. The present study reviewed the possible mechanisms of MetS in patients with CKD, including the disorders of glucose and fat metabolism after kidney injury, IR, HTN and the administration of glucocorticoid and calcineurin inhibitors. In addition, this study reviewed the effect of MetS in patients with CKD on important target organs such as the kidney, heart, brain and blood vessels, and the treatment and prevention of CKD combined with MetS. The study aims to provide strategies for the diagnosis, treatment and prevention of CKD in patients with MetS.

Metabolic complications in lung transplantation for cystic fibrosis - A case control study

Background

Metabolic complications post-lung transplant are poorly understood and little is known about how these complications differ between patients with or without cystic fibrosis (pwCF and pwoCF). This study compared post-lung transplant outcomes between pwCF and pwoCF relating to survival and incidence of diabetes, dyslipidaemia, hypertension, and renal impairment.

Methods

A retrospective (2004-2017) case-control study involving 90 pwCF and 90 pwoCF (age, sex and year of transplant matched) was conducted. Demographic variables, pre/post-transplant metabolic diseases, blood investigations and medications were extracted. Descriptive statistics were used to describe the cohort. Mann-Whitney U and Chi-squared tests were used to analyse morbidity and mortality data. Regression analyses were used to identity independent variables that impacted clinical outcomes. Kaplan Meier analysis with log-rank testing was used to compare survival.

Results

PwCF were younger, had lower BMIs, and were less likely to have pre-transplant extracorporeal membrane oxygenation (ECMO) use. A total of 37 pwCF and 41 pwoCF died (p = 0.65) during the period of observation with no differences in survival. Adjusting for covariates of age, sex and BMI via multiple logistic regression, CF status was associated with a dramatic increased risk of new-onset diabetes post-transplant (adjusted odds ratio 28.7; 95 % CI, 28.76 to 108.7). No other differences in adjusted risk were found.

Conclusions

As pwCF had a greater adjusted risk of developing new post-transplant diabetes and experienced metabolic complications at similar rates as pwoCF, the findings highlight the need for rigorous monitoring of pwCF for possible metabolic complications post-transplant.

Prevalence of Liver Steatosis in Tuberous Sclerosis Complex Patients: A Retrospective Cross-Sectional Study

Introduction: Tuberous sclerosis complex (TSC) is a genetic disease caused by pathogenetic variants in either the TSC1 or TSC2 genes. Consequently, the mechanistic target of the rapamycin complex 1 (mTORC1) pathway, a regulator of cell growth, metabolism, and survival, becomes inappropriately activated, leading to the development of benign tumors in multiple organs. The role of mTORC1 in lipid metabolism and liver steatosis in TSC patients has not been well-studied, and clinical data on liver involvement in this population are scarce. Methods: We conducted a retrospective, cross-sectional study to compare liver steatosis in TSC patients with age-, sex-, BMI-, and diabetes status-matched controls. Participants with a definite diagnosis of TSC were recruited from the TSC clinic at UZ Brussel. Liver steatosis was quantified using the fat signal fraction from in-phase and out-of-phase MRI, with a threshold of ≥5% defining the presence of steatosis. We also evaluated the prevalence of liver angiomyolipomata in the TSC group and analyzed risk factors for both liver steatosis and angiomyolipomata. Results: The study included 59 TSC patients and 59 matched controls. The mean fat signal fraction was 4.0% in the TSC group and 3.9% in the controls, showing no significant difference (two-tailed Wilcoxon signed ranks test, p = 0.950). Liver steatosis was observed in 15.3% of TSC patients compared to 23.7% of the controls, which was not statistically significant (two-tailed McNemar test, p = 0.267). Liver angiomyolipomata were identified in 13.6% of the TSC cohort. Conclusions: Our study, describing in detail the liver phenotype of TSC patients, did not reveal a significant difference in the prevalence of MRI-assessed liver steatosis in a large cohort of TSC patients compared to a closely matched control group.

Impact of varied immunosuppressive agents and posttransplant diabetes mellitus on prognosis among diverse transplant recipients (Experimental studies)

The success of solid organ transplantation (SOT) and the use of immunosuppressive agents offer hope to patients with end-stage diseases. However, the impact of posttransplant diabetes mellitus (PTDM) on SOT patients has become increasingly evident. In our study, we utilized the Scientific Registry of Transplant Recipients (SRTR) database to investigate the association between PTDM and patient survival in various types of organ transplantations, including liver, kidney, intestinal, heart, lung, and combined heart-lung transplantations (all P<0.001). Our findings revealed a negative effect of PTDM on the survival of these patients. Furthermore, we examined the effects of both generic and innovator immunosuppressive agents on the development of PTDM and the overall survival of different SOT populations. Interestingly, the results were inconsistent, indicating that the impact of these agents may vary depending on the specific type of transplantation and patient population. Overall, our study provides a comprehensive and systematic assessment of the effects of different immunosuppressive agents on prognosis, as well as the impact of PTDM on the survival of patients undergoing various types of SOT. These findings emphasize the need for further research and highlight the importance of optimizing immunosuppressive regimens and managing PTDM in SOT patients to improve their long-term outcomes.

Global Leadership Initiative on Malnutrition-Diagnosed Malnutrition in Lung Transplant Candidates

BACKGROUND AND AIMS

Malnutrition in lung transplantation (LT) candidates increases postoperative morbidity and mortality. Early diagnosis of malnutrition could attenuate adverse prognostic factors. This study aimed to assess the prevalence of nutritional risk and malnutrition using GLIM criteria in LT candidates and clinically characterize those with malnutrition.

METHODS

A prospective longitudinal study was conducted from 2000 to 2020 of LT candidates who underwent complete nutritional assessment (nutritional screening, anthropometry, bioelectrical impedance, blood laboratory tests and malnutrition diagnosis using GLIM criteria).

RESULTS

Obstructive diseases (45.6%), interstitial diseases (36.6%) and cystic fibrosis/non-cystic fibrosis bronchiectasis (15.4%) were the main conditions assessed for LT. Of the 1060 candidates evaluated, 10.6% were underweight according to BMI, 29% were at risk of malnutrition and 47% were diagnosed with malnutrition using GLIM criteria. Reduced muscle mass was the most frequent GLIM phenotypic criterion. Malnutrition was more prevalent in patients with cystic fibrosis/non-cystic fibrosis bronchiectasis (84.5%) and obstructive (45.4%) and interstitial (31.3%) diseases. GLIM criteria detected some degree of malnutrition in all diseases requiring LT and identified patients with higher CRP levels and worse respiratory function, anthropometric measurements and visceral protein and lipid profiles.

CONCLUSIONS

LT candidates present a high prevalence of malnutrition using the GLIM algorithm. GLIM criteria detected malnutrition in all diseases requiring LT and defined patients with worse clinical-analytical profiles.

Rapid intestinal and systemic metabolic reprogramming in an immunosuppressed environment

Intrinsic metabolism shapes the immune environment associated with immune suppression and tolerance in settings such as organ transplantation and cancer. However, little is known about the metabolic activities in an immunosuppressive environment. In this study, we employed metagenomic, metabolomic, and immunological approaches to profile the early effects of the immunosuppressant drug tacrolimus, antibiotics, or both in gut lumen and circulation using a murine model. Tacrolimus induced rapid and profound alterations in metabolic activities within two days of treatment, prior to alterations in gut microbiota composition and structure. The metabolic profile and gut microbiome after seven days of treatment was distinct from that after two days of treatment, indicating continuous drug effects on both gut microbial ecosystem and host metabolism. The most affected taxonomic groups are Clostriales and Verrucomicrobiae (i.e., Akkermansia muciniphila), and the most affected metabolic pathways included a group of interconnected amino acids, bile acid conjugation, glucose homeostasis, and energy production. Highly correlated metabolic changes were observed between lumen and serum metabolism, supporting their significant interactions. Despite a small sample size, this study explored the largely uncharacterized microbial and metabolic events in an immunosuppressed environment and demonstrated that early changes in metabolic activities can have significant implications that may serve as antecedent biomarkers of immune activation or quiescence. To understand the intricate relationships among gut microbiome, metabolic activities, and immune cells in an immune suppressed environment is a prerequisite for developing strategies to monitor and optimize alloimmune responses that determine transplant outcomes.

Mortality and Cardiovascular Outcomes in Adult Non-Liver Solid Organ Transplant Patients With Nonalcoholic Steatohepatitis

BACKGROUND

The effect of nonalcoholic steatohepatitis (NASH) on mortality or major adverse cardiovascular events (MACE) in non-liver solid organ transplant recipients (NL-SOT) is unknown.

METHODS

Using a retrospective design, adult NL-SOT recipients who had biopsy-proven NASH were compared NL-SOT recipients with normal liver function tests and imaging; propensity matched at a 1:10 ratio on the following: age, sex, race, transplant year, transplant organ, smoking status, and diabetes status. Both deceased and living donor recipients were included; heart and liver transplant patients were excluded. Primary outcome was incidence of all-cause mortality and MACE (a composite outcome of coronary artery disease, ischemic stroke, and peripheral arterial disease).

RESULTS

Seven patients (3 kidney and 4 lung transplants) had biopsy-proven NASH and 70 patients without NASH, both groups were predominantly male (53%-57%), White (86%-91%), and overweight (mean body mass index ∼ 26). The majority of patients were on calcineurin inhibitors (≥85%), antimetabolites (≥97%), and prednisone (≥50%). Survival analysis showed that NASH patients had a higher risk of death (hazard ratio [HR], 3.24; 95% confidence interval [CI], 1.26-8.33, P = 0.02). NASH did not affect the risk of death-censored graft failure (HR, 1.08; 95% CI, 0.14-8.67; P = .94) or the risk of MACE (HR, 1.03; 95% CI, 0.23-4.62; P = .97).

CONCLUSIONS

In NL-SOT recipients, NASH is significantly associated with mortality but not with MACE.

Rapid intestinal and systemic metabolic reprogramming in an immunosuppressed environment

Intrinsic metabolism shapes the immune environment associated with immune suppression and tolerance in settings such as organ transplantation and cancer. However, little is known about the metabolic activities in an immunosuppressive environment. In this study, we employed metagenomic, metabolomic, and immunological approaches to profile the early effects of the immunosuppressant drug tacrolimus, antibiotics, or both in gut lumen and circulation using a murine model. Tacrolimus induced rapid and profound alterations in metabolic activities within two days of treatment, prior to alterations in gut microbiota composition and structure. The metabolic profile and gut microbiome after seven days of treatment was distinct from that after two days of treatment, indicating continuous drug effects on both gut microbial ecosystem and host metabolism. The most affected taxonomic groups are Clostriales and Verrucomicrobiae (i.e., Akkermansia muciniphila), and the most affected metabolic pathways included a group of interconnected amino acids, bile acid conjugation, glucose homeostasis, and energy production. Highly correlated metabolic changes were observed between lumen and serum metabolism, supporting their significant interactions. Despite a small sample size, this study explored the largely uncharacterized microbial and metabolic events in an immunosuppressed environment and demonstrated that early changes in metabolic activities can have significant implications that may serve as antecedent biomarkers of immune activation or quiescence. To understand the intricate relationships among gut microbiome, metabolic activities, and immune cells in an immune suppressed environment is a prerequisite for developing strategies to monitor and optimize alloimmune responses that determine transplant outcomes.

Pancreatic Exocrine Secretion and Weight Gain After Pancreas Transplantation

INTRODUCTION

Weight gain after pancreas transplant is a poorly understood phenomenon thought to be related to increased posttransplant insulin production, immunosuppressive medications, and appetite changes. No study has investigated the effect of increased exocrine secretion posttransplant.

AIMS AND HYPOTHESIS

We hypothesized that exocrine function, measured by fecal elastase-1 (FE-1), was normal posttransplant and not correlated with weight gain. Our primary aim was to investigate changes in FE-1 levels with pancreas transplantation and to correlate this with weight gain. Establishing weight trends and identifying additional correlating factors were secondary aims.

DESIGN

Forty-two patients that underwent simultaneous pancreas and kidney or pancreas after kidney transplant at a single center between 2013 and 2021 were included. Fecal elastase was measured prospectively in each patient at a single time point, with >500 µg/g categorized as high. Weight and C-peptide values were obtained. All the patients were on steroid-free immunosuppression.

RESULTS

Nineteen patients (45%) had fecal elastase levels >500 µg/g, with a maximum of 3910 µg/g; 43% had levels greater than twice the upper limit of normal. The biggest increase in weight occurred between years 1 and 2, which continued to a median weight gain of 14% at 3 years. There was no correlation between weight gain and FE-1, pretransplant C-peptide levels, or duration of diabetes.

CONCLUSION

This study demonstrated supranormal fecal elastase levels and weight gain posttransplant; however, there was no correlation. Future study with serial FE-1 before and after transplant is needed to better assess its correlation with weight gain.

Serum resistin and the risk for hepatocellular carcinoma in diabetic patients

Hepatocellular carcinoma (HCC), the predominant type of liver cancer, is a major contributor to cancer-related fatalities across the globe. Diabetes has been identified as a significant risk factor for HCC, with recent research indicating that the hormone resistin could be involved in the onset and advancement of HCC in diabetic individuals. Resistin is a hormone that is known to be involved in inflammation and insulin resistance. Patients with HCC have been observed to exhibit increased resistin levels, which could be correlated with more severe disease stages and unfavourable prognoses. Nevertheless, the exact processes through which resistin influences the development and progression of HCC in diabetic patients remain unclear. This article aims to examine the existing literature on the possible use of resistin levels as a biomarker for HCC development and monitoring. Furthermore, it reviews the possible pathways of HCC initiation due to elevated resistin and offers new perspectives on comprehending the fundamental mechanisms of HCC in diabetic patients. Gaining a better understanding of these processes may yield valuable insights into HCC’s development and progression, as well as identify possible avenues for prevention and therapy.

The plasma degradome reflects later development of NASH fibrosis after liver transplant

Although liver transplantation (LT) is an effective therapy for cirrhosis, the risk of post-LT NASH is alarmingly high and is associated with accelerated progression to fibrosis/cirrhosis, cardiovascular disease, and decreased survival. Lack of risk stratification strategies hamper liver undergoes significant remodeling during inflammatory injury. During such remodeling, degraded peptide fragments (i.e., 'degradome') of the ECM and other proteins increase in plasma, making it a useful diagnostic/prognostic tool in chronic liver disease. To investigate whether inflammatory liver injury caused by post-LT NASH would yield a unique degradome profile, predictive of severe post-LT NASH fibrosis, we performed a retrospective analysis of 22 biobanked samples from the Starzl Transplantation Institute (12 with post-LT NASH after 5 years and 10 without). Total plasma peptides were isolated and analyzed by 1D-LC-MS/MS analysis using a Proxeon EASY-nLC 1000 UHPLC and nanoelectrospray ionization into an Orbitrap Elite mass spectrometer. Qualitative and quantitative peptide features data were developed from MSn datasets using PEAKS Studio X (v10). LC-MS/MS yielded ∼2700 identifiable peptide features based on the results from Peaks Studio analysis. Several peptides were significantly altered in patients that later developed fibrosis and heatmap analysis of the top 25 most significantly-changed peptides, most of which were ECM-derived, clustered the 2 patient groups well. Supervised modeling of the dataset indicated that a fraction of the total peptide signal (∼15%) could explain the differences between the groups, indicating a strong potential for representative biomarker selection. A similar degradome profile was observed when the plasma degradome patterns were compared being obesity sensitive (C57Bl6/J) and insensitive (AJ) mouse strains. Both The plasma degradome profile of post-LT patients yields stark difference based on later development of post-LT NASH fibrosis. This approach could yield new "fingerprints" that can serve as minimally-invasive biomarkers of negative outcomes post-LT.

Calcineurin inhibitors' impact on cardiovascular and renal function, a descriptive study in lung transplant recipients from the North of Spain

Patients undergoing lung transplantation (LTx) need administration of immunosuppressive therapy following the procedure to prevent graft rejection. However, these drugs are not exempt from potential risks. The development of cardiovascular risk factors and impaired renal function in the post-transplantation period are conditions that may be favoured by the use of calcineurin inhibitor (CNI) drugs which could have repercussions on the quality of life and the post-transplantation evolution. To evaluate the cardiovascular and renal toxicity following the administration of CNI as maintenance immunosuppression in lung transplant recipients (LTRs) we reviewed a total number of 165 patients undergoing LTx between 01/01/2015 and 08/12/2018. They were divided into two groups according to the CNI drug administrated: cyclosporine (CsA-group) with 11 patients or tacrolimus (Tac-group), with 154 patients. We evaluated the de novo occurrence of arterial hypertension (HTN), diabetes mellitus (DM), hyperlipidemia and impaired renal function after initiation of CNI administration. In addition to that, the time until each of these events was assessed. A higher rate for developing HTN (p < 0.001) and impaired renal function (p = 0.047) was observed within the CsA-group. The new onset of hyperlipidemia was similar between both CNI groups and de novo appearance of DM was only documented in those LTRs receiving tacrolimus. In this LTRs retrospective study, it was observed that having ≥ 4 tacrolimus trough levels above the upper limit of the proposed interval for each specific post-LTx period was associated with an increased risk for developing renal impairment. No other statistically significant association was found between supratherapeutic CNIs blood levels and the evaluated toxicities.

Locally controlled release of immunosuppressive promotes survival of transplanted adult spinal cord tissue

Transplantation of adult spinal cord tissue (aSCT) is a promising treatment for spinal cord injury (SCI) basing on various types of neural cells and matrix components inside aSCT. However, long-term systemic administration of immunosuppressors (e.g. tacrolimus, TAC) is required for the survival of allogeneic tissue, which often associated with severe side effects such as infection, liver damageand renal failure. In this study, a triglycerol monostearate (TGM)-based TAC delivery system (e.g. TAC@TGM) with high drug loading concentration was developed, which possessed injectable properties as well as sustainable and immune-responsive drug release behaviors. In complete transected SCI model, locally injected TAC@TGM could reduce the infiltration of inflammation cells, enhance the survival of transplanted aSCT (e.g. Tuj-1⁺ and NF⁺ neurons) and promote the recovery of locomotor function. Moreover, controlled release of TAC by TAC@TGM attenuated side effects of TAC on liver and kidneys compared with traditional systemic administration. More importantly, the developed TAC@TGM system provided a facile single dose of long-term immunosuppressive effect not just for aSCT transplantation, but also for other tissue/organ and cell transplantations.

Metabolic mechanisms for and treatment of NAFLD or NASH occurring after liver transplantation

The rising tide of non-alcoholic fatty liver disease (NAFLD) associated with the obesity epidemic is a major health concern worldwide. NAFLD - specifically its more advanced form, non-alcoholic steatohepatitis (NASH)-related cirrhosis - is now the fastest growing indication for liver transplantation in the USA and Europe. Although the short-term and mid-term overall survival rates of patients who receive a liver transplant for NASH-related cirrhosis are essentially similar to those of patients who receive a transplant for other liver indications, recipients with NASH-related cirrhosis have an increased risk of waiting-list mortality and of developing recurrent liver disease and cardiometabolic complications in the longer term after liver transplantation. This Review provides a brief overview of the epidemiology of NAFLD and NASH and the occurrence of NAFLD or NASH in patients after liver transplantation for NASH and other liver indications. It also discusses the putative metabolic mechanisms underlying the emergence of NAFLD or NASH after liver transplantation as well as optimal therapeutic approaches for recipients of liver transplants, including the management of cardiometabolic comorbidities, tailored immunosuppression, lifestyle changes and pharmacotherapy for NAFLD.

Genetic factors underlying tacrolimus intolerance after liver transplantation

Background

Tacrolimus (FK506) is the cornerstone of immunosuppression after liver transplantation (LT), however, clinically, switching from FK506 to cyclosporine (SFTC) is common in LT patients with tacrolimus intolerance. The aim of this study was to investigate the genetic risk of patients with tacrolimus intolerance.

Methods

A total of 114 LT patients were enrolled in this retrospective study. SNPs were genotyped using Infinium Human Exome-12 v1.2 BeadChip, and genome-wide gene expression levels were profiled using Agilent G4112F array.

Results

SFTC was a potential risk factor of dyslipidemia (OR=4.774[1.122-20.311], p = 0.034) and insulin resistance (IR) (OR=6.25[1.451-26.916], p = 0.014), but did not affect the survival of LT patients. Differential expression analysis showed donor CYP3A5, CYP2C9, CFTR, and GSTP1, four important pharmacogenetic genes were significantly up-regulated in the tacrolimus intolerance group. Twelve SNPs of these four genes were screened to investigate the effects on tacrolimus intolerance. Regression analysis showed donor rs4646450 (OR=3.23 [1.22-8.60] per each A allele, p = 0.01), donor rs6977165 (OR=6.44 [1.09-37.87] per each C allele, p = 0.02), and donor rs776746 (OR=3.31 [1.25-8.81] per each A allele, p = 0.01) were independent risk factors of tacrolimus intolerance.

Conclusions

These results suggested that SFTC was a potential risk factor for dyslipidemia and IR after LT. Besides, rs4646450, rs6977165, and rs776746 of CYP3A5 might be the underlying genetic risks of tacrolimus intolerance. This might help transplant surgeons make earlier clinical decisions about the use of immunosuppression.

New-onset Obesity After Lung Transplantation: Incidence, Risk Factors, and Clinical Outcomes

BACKGROUND

Lung transplant (LTx) recipients who gain weight after transplantation may experience an upward shift in body mass index (BMI) that places them in the obese category. The incidence, risk factors, and impact on metabolic health and mortality of new-onset obesity have not been documented in the LTx setting.

METHODS

This single-center retrospective study included 564 LTx recipients. Individuals were stratified according to their BMI trajectories from pretransplant evaluation up to 10 y posttransplant. New-onset obesity was defined as a pretransplant BMI <30 kg/m2 and posttransplant BMI >30 kg/m2. The incidence, risk factors, and posttransplant diabetes mellitus, metabolic syndrome, and mortality of recipients with new-onset obesity were compared with those of nonobese (BMI <30 kg/m2, pre/post-LTx), consistently obese (BMI >30 kg/m2, pre/post-LTx), and obese recipients with weight loss (BMI >30 kg/m2 pre-LTx, BMI <30 kg/m2 post-LTx).

RESULTS

We found that 14% of recipients developed obesity after transplantation. Overweight individuals (odds ratio [OR]: 9.01; 95% confidence interval [CI] [4.86-16.69]; P < 0.001) and candidates with chronic obstructive pulmonary disease (OR: 6.93; 95% CI [2.30-20.85]; P = 0.001) and other diagnoses (OR: 4.28; 95% CI [1.22-14.98]; P = 0.023) were at greater risk. Multivariable regression analysis showed that new-onset obesity was associated with a greater risk of metabolic syndrome (hazard ratio: 1.70; 95% CI [1.17-2.46]; P = 0.005), but not of posttransplant diabetes mellitus, than nonobesity. Recipients with new-onset obesity had a survival comparable to that of consistently obese individuals.

CONCLUSIONS

A greater understanding of the multifaceted nature of post-LTx obesity may lead to interventions that are better tailored to the characteristics of these individuals.

Special Considerations in the Management of HIV and Viral Hepatitis Coinfections in Liver Transplantation

Modern therapies for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus have become so effective that patients treated for these conditions can have normal life-expectancies. Suitable livers for transplantation remain a scarce and valuable resource. As such, significant efforts have been made to expand donation criteria at many centers. This constant pressure, coupled with the increasing effectiveness of antiviral therapies, has meant that more and more patients infected with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) may be considered appropriate donors in the right circumstances. Patients with these infections are also more likely to be considered appropriate transplantation recipients than in the past. The treatment of HBV, HCV, and HIV after liver transplantation (LT) can be challenging and complicated by viral coinfections. The various pharmaceutical agents used to treat these infections, as well as the immunosuppressants used post-LT must be carefully balanced for maximum efficacy, and to avoid resistance and drug–drug interactions.

Is Intestinal Dysbiosis-Associated With Immunosuppressive Therapy a Key Factor in the Pathophysiology of Post-Transplant Diabetes Mellitus?

Post-transplant diabetes mellitus (PTDM) is one of the most common and deleterious comorbidities after solid organ transplantation (SOT). Its incidence varies depending on the organs transplanted and can affect up to 40% of patients. Current research indicates that PTDM shares several common features with type 2 diabetes mellitus (T2DM) in non-transplant populations. However, the pathophysiology of PTDM is still poorly characterized. Therefore, ways should be sought to improve its diagnosis and therapeutic management. A clear correlation has been made between PTDM and the use of immunosuppressants. Moreover, immunosuppressants are known to induce gut microbiota alterations, also called intestinal dysbiosis. Whereas the role of intestinal dysbiosis in the development of T2DM has been well documented, little is known about its impacts on PTDM. Functional alterations associated with intestinal dysbiosis, especially defects in pathways generating physiologically active bacterial metabolites (e.g., short-chain fatty acids, trimethylamine N-oxide, indole and kynurenine) are known to favour several metabolic disorders. This publication aims at discussing the potential role of intestinal dysbiosis and dysregulation of bacterial metabolites associated with immunosuppressive therapy in the occurrence of PTDM.

Management of Autoimmune Liver Diseases after Liver Transplantation

Autoimmune liver diseases are characterized by immune-mediated inflammation and eventual destruction of the hepatocytes and the biliary epithelial cells. They can progress to irreversible liver damage requiring liver transplantation. The post-liver transplant goals of treatment include improving the recipient’s survival, preventing liver graft-failure, and decreasing the recurrence of the disease. The keystone in post-liver transplant management for autoimmune liver diseases relies on identifying which would be the most appropriate immunosuppressive maintenance therapy. The combination of a steroid and a calcineurin inhibitor is the current immunosuppressive regimen of choice for autoimmune hepatitis. A gradual withdrawal of glucocorticoids is also recommended. On the other hand, ursodeoxycholic acid should be initiated soon after liver transplant to prevent recurrence and improve graft and patient survival in primary biliary cholangitis recipients. Unlike the previously mentioned autoimmune diseases, there are not immunosuppressive or disease-modifying agents available for patients with primary sclerosing cholangitis. However, colectomy and annual colonoscopy are key components during the post-liver transplant period.