Prevalence and risk factors of steatosis after liver transplantation and patient outcomes.

Steatosis occurs frequently after liver transplantation (LT). We aimed to determine the prevalence of steatosis in adult LT recipients, to determine the effects of significant (>33%; grades 2-3) steatosis on patient survival, and to identify risk factors for the development of significant steatosis and its effect on fibrosis progression. We retrospectively examined 2360 posttransplant biopsies of 548 LT recipients. Survival was compared between patients with significant steatosis and those with grades 0-1 steatosis. Patients with significant steatosis were compared to controls without steatosis (grade 0) for clinical and laboratory factors and fibrosis progression. Steatosis was found in 309 (56.4%) patients, including 93 (17.0%) patients with significant steatosis. Steatohepatitis (nonalcoholic fatty liver disease activity score ≥ 5) was diagnosed in 57 (10.4%) patients. The prevalence of steatosis increased from 30.3% at 1 year to 47.6% at 10 years after LT (P < 0.001). Survival times did not differ between groups (P = 0.29). On multivariate analysis of pretransplant factors and initial immunosuppression (IS), alcohol-induced cirrhosis (P < 0.001) and high body mass index (BMI; P = 0.002) were associated with the development of significant steatosis, whereas increased levels of alkaline phosphatase (P = 0.01) and mycophenolate mofetil given initially (P = 0.009) appeared to protect against significant steatosis. On multivariate analysis of posttransplant factors, high BMI (P < 0.001), serum triglycerides (P < 0.001), alcohol consumption (P = 0.005), and type 2 diabetes mellitus (P = 0.048) were associated with significant steatosis, whereas high creatinine (P = 0.02) appeared to protect against significant steatosis. Significant steatosis was not associated with a higher fibrosis stage (P = 0.62). Posttransplant steatosis affects 56.4% of LT recipients, and the prevalence increases with time after LT. Recipient factors and types of IS affect the risk for significant steatosis, which is not associated with a higher fibrosis stage or worse patient survival. Liver Transplantation 22 644-655 2016 AASLD.

Changes in the brain during long-term follow-up after liver transplantation.

PURPOSE: To examine changes in the brain before liver transplantation caused by the accumulation of paramagnetic ion deposits and to investigate recovery after liver transplantation over a long-term horizon. MATERIALS AND METHODS: Fifteen patients indicated for liver transplantation, 26 patients up to 2 years after, and 40 patients 8-15 years after liver transplantation were subjected to MR relaxometry. T(1) and T(2) relaxation times in the basal ganglia, thalamus, and white matter were evaluated. RESULTS: Relaxometry revealed a shortening of the relaxation times due to the deposition of paramagnetic ions in the basal ganglia before liver transplantation (P < 0.05), complete normalization of the relaxation times shortly after transplantation in the globus pallidus and caudate nucleus, and partial recovery of T(2) in the putamen. Relaxation times remained stable even 15 years posttransplantation. Increased relaxation times posttransplantation were found in the white matter and thalamus. CONCLUSION: The shortening of the relaxation times observed in the basal ganglia before liver transplantation was caused by paramagnetic ion deposition. The recovery observable within 2 years after transplantation was permanent, and no recurrence of paramagnetic ion deposition was observed even 15 years posttransplantation. Changes in the white matter and thalamus after transplantation were attributed to damage caused by permanent exposure to immunosuppressants.

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

OBJECT: Among several non-invasive methods of liver fat analysis, the most important role is played by MR imaging and spectroscopy (MRS). This study describes the 1H MRS at 3T measurement of liver fat volume fraction Φ(fat) in a group of liver transplant patients, an at-risk group for the development of de novo steatosis. MATERIALS AND METHODS: Seventy-seven liver transplant recipients who underwent routine protocolar posttransplant examination were divided into three groups: CON-PAT (control group for the cross validation test, 48 patients), PAT-PAT (patients test group for the cross validation test, 29 patients), and PAT (pooled data). Single voxel 1H MRS at 3T was used for the determination of Φ(fat) and histology results (His) were used as the reference standard. RESULTS: Linear and non-linear regression models were used to describe the relationship between Φ(fat) and His. Strong correlation was found for both models with r = 0.83-0.94 (P < 0.001); a higher r was found for non-linear regression in all tested groups. Areas under receiver operation curves were calculated for cut points His ≥ 5 and > 33% and were found in the range of 0.77-0.86. Fibrosis influences the calculation of Φ(fat) and different slopes were obtained for fibrosis stages F0-F1 and F2-F3, respectively. CONCLUSION: Significant correlation was found between the results of histology and 1H MRS measurement of liver fat content. The method is suitable for non-invasive repetitive examination of liver fat in liver-transplants patients between protocol biopsies and for the screening of steatosis in other liver diseases.

[Determination of liver triglycerides by 1H MR spectroscopy]. / Stanovení obsahu jaterního tuku metodou 1H MR spektroskopie.

BACKGROUND: Metabolic syndrome is responsible for increasing the fat content of the liver. Among several non-invasive methods of liver fat analysis, the most important role is played by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). This pilot study describes the methodology for measurements of triglycerides in the liver in a group of liver transplant patients using 1H MRS at 3T. METHODS AND RESULTS: Thirty-eight patients (12 Female, 27 male, aged 19-71) who underwent routine preventive examination at IKEM were included in the MRS study. The fat content of liver biopsies was classified according to the number of affected hepatocytes, HIS. Based on this classification, there were 20 patients with a steatosis score of S0, 15 patients with a score of S1, 2 patients with a score of S2 and 1 patient with a score of S3. 1H MR spectra were measured from three positions in the liver. Following Longo et al, the concentration of fat phi(fat), was calculated from the signal intensities of water and triglycerides. Linear correlation between the number of affected hepatocytes and fat content was described by the equation: HIS = 6.4 phi(fat) -2.1; r2 = 0.85; p = 0.001. CONCLUSIONS: The pilot study confirmed that examination of fat content using 1H MRS at 3T is well tolerated by patients. Significant correlation was found between the results of histology and 1H MRS measurement of liver fat content. The method is suitable for non-invasive repetitive and screening examination measurement of fat in the liver.