De novo fatty liver due to vascular complications after liver transplantation

Association between obesity after liver transplantation and steatosis, inflammation, and fibrosis of the graft

BACKGROUND

Nonalcoholic steatohepatitis has become one of the leading causes of liver transplantation. The development of steatosis, as well as the link to inflammation and fibrosis, after transplantation remain poorly understood. The aim of this analysis was to evaluate the influence of obesity on histopathological changes of the graft during long-term follow-up.

METHODS

A total of 1494 longitudinal liver biopsies of 271 recipients were evaluated during a follow-up period of 5 to 10 years. Clinical and laboratory parameters as well as histopathological categories of steatosis, inflammation, and fibrosis were explored by routine protocol biopsies.

RESULTS

The BMI and prevalence of diabetes mellitus significantly increased after transplantation (P < .01). Diabetes and de novo obesity were significantly associated with the degree of graft steatosis. There was no correlation between former steatosis and inflammation or fibrosis. Inflammation was a precursor of fibrosis, and fibrosis increased over the first 3 years (P < .01). No severe graft dysfunction was observed.

CONCLUSION

Obesity and diabetes mellitus correlated with higher grades of steatosis and de novo steatosis after transplantation. Metabolic syndrome must be considered as a serious post-transplant complication that can cause histopathological alteration. However, the progress from steatosis to steatohepatitis is not as common as expected.

Hepatic steatosis after pediatric liver transplant

Hepatic steatosis develops after liver transplantation (LT) in 30% of adults, and nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in nontransplanted children. However, posttransplant steatosis has been minimally studied in pediatric LT recipients. We explored the prevalence, persistence, and association with chronic liver damage of hepatic steatosis in these children. In this single-center study of pediatric patients transplanted 1988-2015 (n = 318), 31% of those with any posttransplant biopsy (n = 271) had ≥ 1 biopsy with steatosis. Median time from transplant to first biopsy with steatosis was 0.8 months (interquartile range [IQR], 0.3-6.5 months) and to last biopsy with steatosis was 5.5 months (IQR, 1.0-24.5 months); 85% of patients with steatosis also had for-cause biopsies without steatosis. All available for-cause biopsies were re-evaluated (n = 104). Of 9 biopsies that could be interpreted as nonalcoholic steatohepatitis (NASH)/borderline NASH, with steatosis plus inflammation or ballooning, 8 also had features of cholestasis or rejection. Among 70 patients with surveillance biopsies 3.6-20.0 years after transplant, only 1 overweight adolescent had a biopsy with NAFLD (grade 1 steatosis, mild inflammation, no ballooning or fibrosis)-despite a 30% prevalence of overweight/obesity in the cohort and 27% with steatosis on previous for-cause biopsy. Steatosis on preceding for-cause biopsy was not associated with portal (P = 0.49) or perivenular fibrosis (P = 0.85) on surveillance biopsy. Hepatic steatosis commonly develops early after transplant in children and adolescents, but it rarely persists. Biopsies that did have steatosis with NASH characteristics were all for-cause, mostly in patients with NAFLD risk factors and/or confounding causes of liver damage. Prospective studies that follow children into adulthood will be needed to evaluate if and when hepatic steatosis presents a longterm risk for pediatric LT recipients. Liver Transplantation 23 957-967 2017 AASLD.

Liver transplantation for nonalcoholic fatty liver disease: New challenges and new opportunities

Nonalcoholic fatty liver disease (NAFLD) is becoming rapidly one of the most common indications for orthotopic liver transplantation in the world. Development of graft steatosis is a significant problem during the post-transplant course, which may happen as a recurrence of pre-existing disease or de novo NAFLD. There are different risk factors that might play a role in development of graft steatosis including post-transplant metabolic syndrome, immune-suppressive medications, genetics and others. There are few studies that assessed the effects of NAFLD on graft and patient survival; most of them were limited by the duration of follow up or by the number of patients. With this review article we will try to shed light on post-liver transplantation NAFLD, significance of the disease, how it develops, risk factors, clinical course and treatment options.

Histologically proven non-alcoholic fatty liver disease and clinically related factors in recipients after liver transplantation

Non-alcoholic fatty liver disease (NAFLD) affects a substantial proportion of the world population, and its prevalence has been increasing. The study was aimed at evaluating the prevalence and peri-transplant risk factors for post-liver transplantation (LT) NAFLD. A retrospective review was performed for adult recipients who underwent late protocol biopsy (>1 yr after LT) between August 2010 and December 2012. Hepatic steatosis was reviewed and graded by hepatopathologists, and the peri-transplant factors were analyzed for relationships to histologically proven NAFLD. Total 166 biopsies had been performed in 156 recipients. NAFLD was present in 27.1% at a mean period of 35.4 months between LT and biopsy, moderate and severe steatosis (≥33%) consisted of 28.9%. In multivariate analysis, pre-LT alcoholic cirrhosis (odds ratio [OR] 8.031, p = 0.003), obesity at biopsy (OR 3.873, p = 0.001), and preexisting donor graft steatosis (OR 3.147, p = 0.022) were significant risk factors for post-LT NAFLD. In conclusion, NAFLD represented a considerable portion of recipients, but this prevalence was not higher than those for general population. Three risk factors were significantly related to post-LT NAFLD, and recipients with those factors should be monitored for NAFLD. Furthermore, possible progression to non-alcoholic steatohepatitis (NASH) or fibrosis and metabolic syndrome should be considered in future studies.

Posttransplant metabolic syndrome in children and adolescents after liver transplantation: a systematic review

During long-term follow-up, 18% to 67% of pediatric liver transplant recipients are overweight or obese, with rates varying by age and pretransplant weight status. A similar prevalence of posttransplant obesity has been seen in adults. Adults also develop posttransplant metabolic syndrome and, consequently, cardiovascular disease at rates that exceed the rates in age- and sex-matched populations. Posttransplant metabolic syndrome has never been studied in pediatric liver transplant recipients, and this population is growing as transplant outcomes continue to improve. Here we systematically review the literature for each component of metabolic syndrome-obesity, hypertension, dyslipidemia, and glucose intolerance-in pediatric liver transplant recipients. Their rates of obesity are similar to the rates in children in the general U.S. population. However, hypertension, dyslipidemia, and diabetes are more common than would be expected in transplant recipients according to age, sex, and obesity severity. Immunosuppressive medications are major contributors. The limitations of previous studies, including heterogeneous methods of diagnosis, follow-up times, and immunosuppressive regimens, hinder the analysis of risk factors. Importantly, no studies have reported graft or patient outcomes associated with components of metabolic syndrome after pediatric liver transplantation. However, if the trends in children are similar to the trends seen in adults, these conditions may lead to significant long-term morbidity. Further research on the prevalence, causes, and consequences of posttransplant metabolic syndrome in pediatric liver transplant recipients is needed and will ultimately help to improve long-term outcomes.