Corticosteroid-free immunosuppression in liver transplantation: An evidence-based review

Transient Elastography for Noninvasive Evaluation of Posttransplant Liver Graft Fibrosis in Turkish Children, Ege University Children Hospital Experience

OBJECTIVES

The influence of advancing fibrosis on graft survival in the context of pediatric liver transplantation accentuates the critical role of protocol-driven liver biopsies, a practice adopted by numerous medical centers. Consequently, the exigency for noninvasive methodologies to assess graft fibrosis assumes heightened importance when conventional clinical and laboratory parameters fail to reveal signs of liver damage.

METHODS

This study aimed to assess the reliability of transient elastography (TE) in pediatric liver transplant recipients to detect graft fibrosis and compare the results of TE in patients who underwent biopsy.

RESULTS

This prospective cohort study included liver transplanted children who underwent biopsy at Ege University Children's Hospital between October 1, 2021, and October 31, 2022, and a healthy control group. According to TE, fibrosis was detected in 40 patients, and no fibrosis was detected in 50. The median time to develop fibrosis was 100 months (95% CI [83.1-116.8]). A statistically significant positive correlation existed between LSM and METAVIR fibrosis score (r = 0.562, p = 0.001). There was a statistically significant difference in LSM between patients with F2 fibrosis (7.8-8.8 kPa ± 3.2) compared to patients with F0 fibrosis (5.2 kPa ± 0.7) (p = 0.005) and F1 fibrosis (6.1 kPa ± 1.5) (p = 0.041), on ANOVA.

CONCLUSION

Liver allograft fibrosis is common in long-term follow-up in children who have undergone liver transplantation. Abnormal TE may guide physicians to consider liver biopsy to detect late allograft fibrosis in these children.

Prediction of New-Onset Diabetes Mellitus within 12 Months after Liver Transplantation-A Machine Learning Approach

BACKGROUND

Liver transplantation (LT) is a routine therapeutic approach for patients with acute liver failure, end-stage liver disease and/or early-stage liver cancer. While 5-year survival rates have increased to over 80%, long-term outcomes are critically influenced by extrahepatic sequelae of LT and immunosuppressive therapy, including diabetes mellitus (DM). In this study, we used machine learning (ML) to predict the probability of new-onset DM following LT.

METHODS

A cohort of 216 LT patients was identified from the Disease Analyzer (DA) database (IQVIA) between 2005 and 2020. Three ML models comprising random forest (RF), logistic regression (LR), and eXtreme Gradient Boosting (XGBoost) were tested as predictors of new-onset DM within 12 months after LT.

RESULTS

18 out of 216 LT patients (8.3%) were diagnosed with DM within 12 months after the index date. The performance of the RF model in predicting the development of DM was the highest (accuracy = 79.5%, AUC 77.5%). It correctly identified 75.0% of the DM patients and 80.0% of the non-DM patients in the testing dataset. In terms of predictive variables, patients' age, frequency and time of proton pump inhibitor prescription as well as prescriptions of analgesics, immunosuppressants, vitamin D, and two antibiotic drugs (broad spectrum penicillins, fluocinolone) were identified.

CONCLUSIONS

Pending external validation, our data suggest that ML models can be used to predict the occurrence of new-onset DM following LT. Such tools could help to identify LT patients at risk of unfavorable outcomes and to implement respective clinical strategies of prevention.

Management and Risks Before, During, and After Liver Transplant in Individuals With Obesity

Obesity has become a global epidemic, adding to the burden of chronic diseases and disabilities. Metabolic syndrome, especially obesity, is a significant risk factor for nonalcoholic fatty liver disease, which is the most common indication for liver transplant (LT). The prevalence of obesity among the LT population is growing. Obesity increases the necessity of LT by playing a role in the development of nonalcoholic fatty liver disease, decompensated cirrhosis, and hepatocellular carcinoma, and it can also coexist with other diseases requiring LT. Therefore, LT teams must identify key aspects required to manage this high-risk population, but there are currently no defined recommendations for managing obesity in LT candidates. Although body mass index is often used to assess the weight of patients and classify them as overweight or obese, this measure may be inaccurate to use in patients with decompensated cirrhosis, as fluid overload or ascites can significantly add to the weight of patients. Diet and exercise remain the cornerstone of obesity management. Supervised weight loss before LT, without worsening frailty and sarcopenia, may be beneficial in reducing surgical risks and improving long-term LT outcomes. Bariatric surgery is another effective treatment for obesity, with sleeve gastrectomy currently conferring the best outcomes in LT recipients. However, evidence supporting the timing of bariatric surgery is lacking. Long-term patient and graft survival data in individuals with obesity following LT are scarce. Class 3 obesity (body mass index ≥40) further complicates the treatment of this patient population. This article discusses the impact of obesity on the outcome of LT.

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.

Multidirectional facets of obesity management in the metabolic syndrome population after liver transplantation

The obesity pandemic has resulted in an increasing demand for liver transplantation and has significantly altered the profile of liver transplant candidates in addition to affecting posttransplantation outcomes. In this review, we discuss a broad range of clinical approaches that warrant attention to provide comprehensive and patient‐centred medical care to liver transplant recipients, and to be prepared to confront the rapidly changing clinical challenges and ensuing dilemmas. Adipose tissue is a complex and metabolically active organ. Visceral fat deposition is a key predictor of overall obesity‐related morbidity and mortality. Limited pharmacological options are available for the treatment of obesity in the liver transplant population. Bariatric surgery may be an alternative in eligible patients. The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global concern; NAFLD affects both pre‐ and posttransplantation outcomes. Numerous studies have investigated pharmacological and nonpharmacological management of NAFLD and some of these have shown promising results. Liver transplant recipients are constantly exposed to numerous factors that result in intestinal microbiota alterations, which were linked to the development of obesity, diabetes type 2, metabolic syndrome (MS), NAFLD, and hepatocellular cancer. Microbiota modifications with probiotics and prebiotics bring gratifying results in the management of metabolic complications. Fecal microbiota transplantation (FMT) is successfully performed in many medical indications. However, the safety and efficacy profiles of FMT in immunocompromised patients remain unclear. Obesity together with immunosuppressive treatment, may affect the pharmacokinetic and/or pharmacodynamic properties of coadministered medications. Individualized immunosuppressive regimens are recommended following liver transplantation to address possible metabolic concerns. Effective and comprehensive management of metabolic complications is shown to yield multiple beneficial results in the liver transplant population and may bring gratifying results in improving long‐term survival rates.

Management of Patients With Non-alcoholic Steatohepatitis Undergoing Liver Transplantation: Considerations for the Anesthesiologist

Non-alcoholic fatty liver disease (NAFLD) currently affects more than 25% of the world population and is rising. NAFLD can progress to non-alcoholic steatohepatitis that is associated with hepatic inflammation and fibrosis and can result in cirrhosis with subsequent liver failure. Non-alcoholic steatohepatitis (NASH) has now emerged as one of the leading etiologies for a liver transplant among adults in the United States. Given the rising incidence of liver transplants in patients with NASH-related cirrhosis, it is essential for anesthesiologists to be familiar with this condition as well as with NASH-related comorbidities and perioperative complications. Not only is NASH linked to metabolic syndrome, but it also is independently associated with cardiovascular disease, renal and thyroid dysfunction, obstructive sleep apnea (OSA), and a hypercoagulable state. The association with these conditions can affect the perioperative outcome of these patients, particularly because of increased mortality from major adverse cardiovascular events and sepsis. In order to decrease the perioperative morbidity and mortality of patients with NASH undergoing a liver transplant, a multidisciplinary approach to their perioperative management is essential, along with careful preoperative evaluation and aggressive intraoperative and postoperative monitoring. The focus of this review article is to provide a comprehensive overview of challenges associated with liver transplants in patients with NASH and to provide suggestions for appropriate patient selection and perioperative management.

Safety and Efficacy of Budesonide for Liver Transplant Immune Suppression: Results of a Pilot Phase 2a Trial

Despite adverse effects like hyperglycemia, new-onset diabetes after transplant (NODAT), and infectious complications, corticosteroid use remains an important part of liver transplantation (LT) immune suppression. Budesonide, a synthetic corticosteroid, undergoes extensive first-pass hepatic metabolism with only 10% systemic bioavailability, providing an opportunity for an improved toxicity-therapeutic ratio. Although effective in the treatment of autoimmune hepatitis, the effects of budesonide for LT immune suppression are unknown. We conducted a single-center phase 2a trial to study the safety and efficacy of budesonide immunosuppressive therapy. From July 2017 to November 2018, 20 patients undergoing a first LT received budesonide tapering doses (from 9 to 3 mg) for 12 weeks. Patients were compared with matched control patients who received prednisone from the same time period. Additionally, both groups received calcineurin inhibitors and mycophenolate mofetil. Outcome measures at week 24 included rates of biopsy-proven acute cellular rejection (ACR), NODAT (hemoglobin A1c >6.4%), and infectious complications. In the budesonide arm, 1 patient developed ACR at week 5 and was removed from the study. Another patient stopped the study drug at week 8 due to persistent nausea. Rates of ACR were similar between the budesonide and control groups (5% versus 5%, P = 1.00). Three patients in the control group developed NODAT versus none in the budesonide group (15% versus 0%; P = 0.23). There were 6 infections in the control group compared with none in the budesonide group (30% versus 0; P = 0.02). These pilot data suggest that budesonide has the potential to be a safe and effective alternative to prednisone for LT immune suppression while reducing steroid-induced infections and NODAT. Randomized controlled trials are required to validate these findings.

Sirolimus and MMF are insufficient immunosuppressants for regulation of the proliferation of CD133+EpCAM+ cell populations in HCC cell lines

Studies on effective immunosuppressive strategies for the management of patients undergoing a liver transplantation (LT) due to hepatocellular carcinoma (HCC) are limited. In the present study, immunosuppressive candidates predicted to exhibit beneficial immunosuppressive and tumor-suppressive effects in patients with HCC were assessed using Huh7 and HEP3B HCC cells, which have high proportions of CD133+EpCAM+ cancer stem cell (CSC) populations. The immunosuppressants assessed were sirolimus, tacrolimus, cyclosporine A and mycophenolate mofetil (MMF), and their activities were assessed on CSCs. Sirolimus and MMF reduced the proliferation of Huh7 and HEP3B cells; however, the proportion of CD133+EpCAM+ was notably increased in treated Huh7 cells. Sirolimus treatment alone resulted in G0-G1 cell cycle arrest at all doses in all Huh7 and CD133-EpCAM- populations; however, CD133+EpCAM+ populations showed only slight G1 arrest at higher doses only. In contrast, S-phase arrest was induced at all doses in the Huh7, CD133-EpCAM- and CD133+EpCAM+ populations by MMF. Sirolimus and MMF effectively reduced the proliferation of Huh7 and HEP3B cells, but did not exert a notable effect on the CD133+EpCAM+ cells. Therefore, therapeutic strategies utilizing Sirolimus and MMF should be further studied in vivo for regulation of CSC populations in order to reduce HCC recurrence rates.

Peri-transplant management of nonalcoholic fatty liver disease in liver transplant candidates

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly growing, affecting 25% of the world population. Non-alcoholic steatohepatitis (NASH) is the most severe form of NAFLD and affects 1.5% to 6.5% of the world population. Its rising incidence will make end-stage liver disease (ESLD) due to NASH the number one indication for liver transplantation (LT) in the next 10 to 20 years, overtaking Hepatitis C. Patients with NASH also have a high prevalence of associated comorbidities such as type 2 diabetes, obesity, metabolic syndrome, cardiovascular disease, and chronic kidney disease (CKD), which must be adequately managed during the peritransplant period for optimal post-transplant outcomes. The focus of this review article is to provide a comprehensive overview of the unique challenges these patients present in the peritransplant period, which comprises the pre-transplant, intraoperative, and immediate postoperative periods.

Obesity in the Liver Transplant Setting

The obesity epidemic has resulted in an increased prevalence of obesity in liver transplant (LT) candidates and in non-alcoholic fatty liver disease (NAFLD) becoming the fastest growing indication for LT. LT teams will be dealing with obesity in the coming years, and it is necessary for them to recognize some key aspects surrounding the LT in obese patients. Obesity by itself should not be considered a contraindication for LT, but it should make LT teams pay special attention to cardiovascular risk assessment, in order to properly select candidates for LT. Obese patients may be at increased risk of perioperative respiratory and infectious complications, and it is necessary to establish preventive strategies. Data on patient and graft survival after LT are controversial and scarce, especially for long-term outcomes, but morbid obesity may adversely affect these outcomes, particularly in NAFLD. The backbone of obesity treatment should be diet and exercise, whilst being careful not to precipitate or worsen frailty and sarcopenia. Bariatric surgery is an alternative for treatment of obesity, and the ideal timing regarding LT is still unknown. Sleeve gastrectomy is probably the procedure that has the best evidence in LT because it offers a good balance between safety and efficacy.

Pro: Steroids Can Be Withdrawn After Transplant in Recipients With Autoimmune Hepatitis

Corticosteroids have been a mainstay of immunosuppression following liver transplantation. However, evolution in the field of transplant immunology has produced steroid-free options, resulting in most transplant centers weaning steroids after transplant within days to months-an evidence-based management decision. Patients with autoimmune hepatitis (AIH), however, receive corticosteroids prior to transplant. This raises the question of whether these patients should also be weaned from corticosteroids. In this review, we discuss the benefits of avoiding steroid use in this population of patients-an approach that not only avoids the adverse effects of corticosteroids but does so without risking graft failure from recurrent AIH or from acute cellular rejection.

Hepatocellular cancer and recurrence after liver transplantation: what about the impact of immunosuppression?

Liver transplantation (LT) has originally been designed to treat hepatobiliary malignancies. The initial results of LT for hepatocellular cancer (HCC) were, however, dismal this mainly due to the poor patient selection procedure. Better surgical and perioperative care and, especially, the refinement of selection criteria led to a major improvement of results, making HCC nowadays (again!) one of the leading indications for LT. This evolution is clearly shown by the innumerable reports aiming to further extend inclusion criteria for LT in HCC patients. Nonetheless, the vast majority of papers only deals with morphologic (tumour diameter and number) and (only recently) biologic (tumour markers and response to locoregional treatment) parameters to do so. Curiously enough, the role of both the immune competent state of the recipient as well as the impact of both immunosuppression (IS) type and load has been very poorly addressed in this context, even if it has been shown for a long time, based on both basic and clinical research, that they all play a key role in the outcome of any oncologic treatment and in the development of de novo as well as recurrent tumours. This chapter aims to give, after a short introductive note about the currently used inclusion criteria of HCC patients for LT and about the role of IS in carcinogenesis, a comprehensive overview of the actual literature related to the impact of different immunosuppressive drugs and schemes on outcome of LT in HCC recipients. Unfortunately, up to now solid conclusions cannot be drawn due to the lack of high-level evidence studies caused by the heterogeneity of the studied patient cohorts and the lack of prospectively designed and randomized studies. Based on long-term personal experience with immunosuppressive handling in LT some proposals for further clinical research and practice are put forward. The strategy of curtailing and minimising IS should be explored in the growing field of transplant oncology taking thereby into account the immunological privilege of the liver allograft. These strategies will become more and more compelling when further extending the indications in which adjuvant chemotherapy will probably become an inherent part of the therapeutic scheme of HCC liver recipients.

Real-World Multicenter Experience of Immunosuppression Minimization Among 661 Liver Transplant Recipients

BACKGROUND Long-term morbidity and mortality in liver transplant recipients is frequently secondary to immunosuppression toxicity. However, data are scarce regarding immunosuppression minimization in clinical practice. MATERIAL AND METHODS In this cross-sectional, multicenter study, we reviewed the indications of immunosuppression minimization (defined as tacrolimus levels below 5 ng/mL or cyclosporine levels below 50 ng/mL) among 661 liver transplant recipients, as well as associated factors and the effect on renal function. RESULTS Fifty-three percent of the patients received minimized immunosuppression. The median time from transplantation to minimization was 32 months. The most frequent indications were renal insufficiency (49%), cardiovascular risk (19%), de novo malignancy (8%), and cardiovascular disease (7%). The factors associated with minimization were older age at transplantation, longer post-transplant follow-up, pre-transplant diabetes mellitus and renal dysfunction, and the hospital where the patients were being followed. The patients who were minimized because of renal insufficiency had a significant improvement in renal function (decrease of the median serum creatinine level, from 1.50 to 1.34 mg/dL; P=0.004). Renal function significantly improved in patients minimized for other indications, too. In the long term, glomerular filtration rate significantly decreased in non-minimized patients and remained stable in minimized patients. CONCLUSIONS Immunosuppression minimization is frequently undertaken in long-term liver transplant recipients, mainly for renal insufficiency. Substantial variability exists regarding the use of IS minimization among centers.

Liver Transplantation: the Role of Metabolic Syndrome

OPINION STATEMENT

The long-term survival in liver transplant recipients (LTRs) is currently at an historical high level stemming from improvement in perioperative care, infection control, and immunosuppression medications. However, compared to the general population, LTRs have decreased survival. Metabolic diseases like hypertension, dyslipidemia, type 2 diabetes, and obesity are key determinants of long-term mortality in LTRs. The incidence and prevalence of these metabolic comorbidities is considerably higher in LTRs and likely results from a combination of factors including exposure to chronic immunosuppression, weight gain, and recurrence of chronic liver disease after liver transplantation (LT). Although there is currently little guidance in managing these metabolic conditions post-LT, recommendations are often extrapolated from non-transplant cohorts. In the current review, we explore the relationship between metabolic syndrome and its comorbidities in LTRs.

Early steroid withdrawal results in improved patient and graft survival and lower risk of post-transplant cardiovascular risk profiles: A single-center 10-year experience

Long-term use of steroids results in predictable secondary effects that can lead to increased morbidity and mortality. In this study, we present 10 years worth of data of early steroid withdrawal (ESW) immunosuppression consisting of mycophenolate, sirolimus, and tacrolimus. From 2003 to 2013, 563 kidney transplant recipients were weaned off steroids prior to discharge. We compared outcomes with that of our 65 historical controls maintained on steroids. We analyzed graft and patient survival and determined the incidence of steroid-related comorbidities such as hypertension, hypercholesterolemia, diabetes, coronary artery disease, and weight gain. Patients on ESW maintenance immunosuppression had improved patient and graft survival compared to controls. (HR: 0.23; P≤.011, 0.57; P=.026). Rates of biopsy-proven acute rejection were not different among both groups (HR: 1.24; P=.610). Incidence of post-transplant diabetes were reduced but not statistically significant (OR: 0.67; P=.138). Additionally, the development of hypertension (OR: 0.86, P≤.01), hypercholesterolemia (RR: 0.82; P=.027), CAD (RR: 0.43; P=.002), and >20 lbs. weight gain (RR: 0.29; P≤.01) was significantly improved over 10 years following initiation of ESW protocols. Early steroid withdrawal in renal transplant recipients results in improved patient and graft survival as well as better rates of post-transplant comorbid conditions.

The Origin of New-Onset Diabetes After Liver Transplantation: Liver, Islets, or Gut?

New-onset diabetes is a frequent complication after solid organ transplantation. Although a number of common factors are associated with the disease, including recipient age, body mass index, hepatitis C infection, and use of immunosuppressive drugs, new-onset diabetes after liver transplantation (NODALT) has the following unique aspects and thus needs to be considered its own entity. First, a liver graft becomes the patient's primary metabolic regulator after liver transplantation, but this would not be the case for kidney or other grafts. The metabolic states, as well as the genetics of the graft, play crucial roles in the development of NODALT. Second, dysfunction of the islets of Langerhans is common in cirrhotic patients and would be exacerbated by immunosuppressive agents, particularly calcineurin inhibitors. On the other hand, minimized immunosuppressive protocols have been widely advocated in liver transplantation because of liver tolerance (immune privilege). Third and last, through the "gut-liver axis," graft function is closely linked to gut microbiota, which is now considered an important metabolic organ and known to independently influence the host's metabolic homeostasis. Liver transplant recipients present with specific gut microbiota that may be prone to trigger metabolic disorders. In this review, we proposed 3 possible sites for the origin of NODALT, which are liver, islets, and gut, to help elucidate the underlying mechanism of NODALT.

Profiling immunologic risk for acute rejection in liver transplantation: Recipient age is an important risk factor

BACKGROUND

Careful management of induction and maintenance of immunosuppression is paramount to prevent acute rejection in liver transplantation. A methodical analysis of risk factors for acute cellular rejection may provide a more comprehensive method to profile the immunologic risk of candidates.

METHODS

Using registry data from the Organ Procurement and Transplantation Network (OPTN), we identified 42,508 adult recipients who underwent orthotopic liver transplant (OLT) between 2002 and 2013. We excluded recipients with a blank entry for treated rejection. We analyzed this all inclusive cohort in addition to a subset of 27,493 patients with just tacrolimus immunosuppression. Multivariate logistic regression was used on both cohorts and identified independent risk factors for treated acute rejection at one year.

RESULTS

Recipient age (reference group was 40 to 60years) was a dominant risk factor for rejection in both cohorts and had a dose response relationship. The strongest risk factors in the inclusive cohort were: age 18-25 (OR 2.20), age 26-29 (OR 2.03), and primary biliary cholangitis (OR 1.55). The most protective factors were age 70 and older (OR 0.68), and age 65-69 (OR 0.70). The rates of rejection had a similar pattern.

CONCLUSIONS

Although prior studies have suggested age as a risk factor for rejection in liver transplantation, this is the first study of national-level data to demonstrate a robust dose dependent relationship between age and risk for rejection at one year. Clinicians should place significant weight on recipient age when they assess their recipients for the immunologic risk of rejection.

Impact of different immunosuppressive regimens on the health-related quality of life following orthotopic liver transplantation

BACKGROUND

The influence of immunosuppression on the recipients' quality of life (QoL) is of major importance after OLT and has not yet been evaluated.

METHODS

The impact of different immunosuppression regimens after OLT was evaluated in 275 patients using the Short Form 36 (SF-36) survey. The following immunosuppressive strategies were compared: (a) CNI, (b) mTOR inhibitors, and (c) mTOR combined with CNI. All regimens were prescribed alone (mono) or in combination (+) with prednisolone and/or mycophenolate mofetil (MMF).

RESULTS

Highest scores were evident in patients in the mTOR+ group. There were significantly higher values for general health perceptions (GH, p = 0.049), vitality (VIT, p = 0.020), and physical component summary (PCS, p = 0.041) when compared to CNImono and for GH (p = 0.042) and VIT (p = 0.043), when compared to mTORmono. Early conversion to mTOR inhibitors (<two months after OLT) was associated with higher values for 7 of 10 scales, when compared to a late conversion (>two months after OLT), with a statistically significant improvement for the dimension role-emotional (RE, p = 0.027).

DISCUSSION

mTOR inhibitor-based regimens appear to have beneficial effects on QoL after OLT, especially after an early conversion.