Non-Alcoholic Fatty Liver Disease After Liver Transplantation: A Case of Nurture and Nature

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. Most patients with cryptogenic cirrhosis are considered to have had " burned out NAFLD. " Although the recurrence and progression of NAFLD after liver transplantation (LT) have been shown previously, the incidence of de novo NAFLD after LT has not been extensively reported. In this issue of the American Journal of Gastroenterology , Dumortier et al. report the incidence of de novo post-LT NAFLD. Although most of the risk factors for post-LT NAFLD are similar to those for primary NAFLD, hepatic steatosis in the donor livers and a pre-transplant diagnosis of alcoholic liver disease remain independent risk factors. Although there are some limitations, this study provides the largest cohort of patients for whom post-LT NAFLD is reported. Am J Gastroenterol 2010; 105:621 -623; doi: 10.1038/ajg.2009 Non-alcoholic fatty liver disease (NAFLD) is currently recognized as one of the most common forms of chronic liver disease. Natural history studies have shown that a proportion of patients, especially those with non-alcoholic steatohepatitis (NASH), will develop progressive liver disease, leading to end-stage liver disease and hepatocellular carcinoma ( 1 ). Moreover, recurrence of NAFLD aft er liver transplantation (LT) is common ( 2 ). Th e risk factors for recurrent NAFLD include post-transplant diabetes, obesity, and hypertriglyceridemia ( 1 ). Progression from simple steatosis to NASH and cirrhosis and even allograft failure has been demonstrated ( 1,3 ).De novo NAFLD aft er LT, however, is not as well studied. Its incidence, risk factors, and natural history are not currently well defi ned. In an early report, 25 % of patients with cholestatic liver disease were noted to develop a fatty liver aft er LT. As pretransplant characteristics as well as explants ' histology were not described for this group of patients, it is diffi cult to determine whether this group had concomitant NAFLD at the time of transplantation and thus whether developing a fatty liver aft er transplant simply represented recurrent disease ( 4 ). Poordad et al. ( 5 ) reported four cases of de novo NAFLD that developed early in the post-transplant setting. In another report, NAFLD developed in 40 % of LT recipients aft er a mean follow-up of 44 months ( 6 ). NASH was seen in 13 % . Seo et al. ( 7 ) reported an incidence of 18 % for NAFLD and 9 % for NASH aft er an average follow-up of 28 months. Th ese early reports are, however, limited by small sample sizes and the relative predominance of chronic hepatitis C as an indication for LT, which has been associated with hepatic steatosis, especially HCV genotype 3 infection. Moreover, the liver biopsies in these studies were performed for clinical indications in the majority of cases as opposed to protocol biopsies, a fact that may aff ect the estimation of the incidence of NAFLD in the post-transplant setting.In this issue of the American Journal of Gastroenterology , Dumortier et al. ( 8 ) report their ...

MR spectroscopy as a tool for in vivo determination of steatosis in liver transplant recipients

“…The development of steatosis in patients with LT has similar symptoms to those in the healthy population. Nevertheless, patients with LT have several specific features-patients are regularly treated with immunosuppression drugs that can, in addition to other symptoms of metabolic syndrome, support de novo development of NAFLD [5]. Conversely, patients are under systematic clinical control and their treatment can be optimized.…”

“…Thinner red and blue dotted lines represent the 95% confidence intervals group based on data of the control group, CON-PAT, which was measured independently. From the MRS results obtained for the PAT-PAT group, the amounts of affected hepatocytes were calculated according to linear and nonlinear equations (5) and (8) (obtained for the CON-PAT group, see Table 3) and classified according to the Kleiner four-level scale. The calculated classifications were compared with the classification based on the results of liver biopsies.…”

“…It is known that steatosis impairs the regenerative capacity of the liver in both donors and recipients [1][2][3][4][5]. The detection and measurement of fat concentration in the liver is, therefore, an important clinical parameter that can be used in the prevention, and can improve the treatment of many diseases.…”

Quality of life 10 years after liver transplantation: The impact of graft histology

“…Post-transplant metabolic syndrome and graft NAFLD are being increasingly recognized as long term problems in LT recipients[19,20]. Patients with post-LT NAFLD develop at the least an increased risk of cardiovascular events, rejection and infection[21].…”

Recurrent diseases following liver transplantation

“…There have been reports, however, that both the onset of rNAFLD and the progression to cirrhosis can be rapid (within 1 year after liver transplantation) [73][74][75][76].…”