Pre-and-post transplant considerations in patients with nonalcoholic fatty liver disease

Induction of liver transplant immune tolerance in an outbred rat strain model using tacrolimus

BACKGROUND

Orthotopic liver transplantation is the only option for patients with end-stage liver disease and hepatocellular carcinoma. Post-transplant immunosuppressive therapy is important to prevent graft failure. We investigated the effectiveness of tacrolimus (FK506) and their mechanisms for liver transplant immune tolerance in an outbred rat LT model.

RESULTS

To investigate the therapeutic effect of the FK506 on outbred rat LT model, FK506 and postoperative therapy were administered subcutaneously once or twice daily to transplanted rats. Histopathological and immunohistochemical analyses were conducted for all groups. The regulation of inflammatory cytokine signaling in the spleen was analyzed by flow cytometry. FK506 attenuated allograft rejection and increased survival in rat orthotopic liver transplantation models. The FK506-treated group had reduced serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Furthermore, FK506 decreased the expression of inflammatory cytokines and the activation of pathogenic Th1 and Th17 cells in the liver.

CONCLUSIONS

Taken together, we revealed that FK506 ameliorated strong allograft rejection in outbred liver transplantation model by anti-inflammatory effect and inhibitory peroperty of pathogenic T cells.

Indian National Association for Study of the Liver (INASL) Guidance Paper on Nomenclature, Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease globally and in India. The already high burden of NAFLD in India is expected to further increase in the future in parallel with the ongoing epidemics of obesity and type 2 diabetes mellitus. Given the high prevalence of NAFLD in the community, it is crucial to identify those at risk of progressive liver disease to streamline referral and guide proper management. Existing guidelines on NAFLD by various international societies fail to capture the entire landscape of NAFLD in India and are often difficult to incorporate in clinical practice due to fundamental differences in sociocultural aspects and health infrastructure available in India. A lot of progress has been made in the field of NAFLD in the 7 years since the initial position paper by the Indian National Association for the Study of Liver on NAFLD in 2015. Further, the ongoing debate on the nomenclature of NAFLD is creating undue confusion among clinical practitioners. The ensuing comprehensive review provides consensus-based, guidance statements on the nomenclature, diagnosis, and treatment of NAFLD that are practically implementable in the Indian setting.

Strategies to Improve Immune Suppression Post-Liver Transplantation: A Review

Since the first liver transplantation operation (LT) in 1967 by Thomas Starzl, efforts to increase survival and prevent rejection have taken place. The development of calcineurin inhibitors (CNIs) in the 1980s led to a surge in survival post-transplantation, and since then, strategies to prevent graft loss and preserve long-term graft function have been prioritized. Allograft rejection is mediated by the host immune response to donor antigens. Prevention of rejection can be achieved through either immunosuppression or induction of tolerance. This leads to a clinical dilemma, as the choice of an immunosuppressive agent is not an easy task, with considerable patient and graft-related morbidities. On the other hand, the induction of graft tolerance remains a challenge. Despite the fact that the liver exhibits less rejection than any other transplanted organs, spontaneous graft tolerance is rare. Most immunosuppressive medications have been incriminated in renal, cardiovascular, and neurological complications, relapse of viral hepatitis, and recurrence of HCC and other cancers. Efforts to minimize immunosuppression are directed toward decreasing medication side effects, increasing cost effectiveness, and decreasing economic burden without increasing the risk of rejection. In this article, we will discuss recent advances in strategies for improving immunosuppression following liver transplantation.

Magnetic Resonance Spectroscopy of Hepatic Fat from Fundamental to Clinical Applications

The number of individuals suffering from fatty liver is increasing worldwide, leading to interest in the noninvasive study of liver fat. Magnetic resonance spectroscopy (MRS) is a powerful tool that allows direct quantification of metabolites in tissue or areas of interest. MRS has been applied in both research and clinical studies to assess liver fat noninvasively in vivo. MRS has also demonstrated excellent performance in liver fat assessment with high sensitivity and specificity compared to biopsy and other imaging modalities. Because of these qualities, MRS has been generally accepted as the reference standard for the noninvasive measurement of liver steatosis. MRS is an evolving technique with high potential as a diagnostic tool in the clinical setting. This review aims to provide a brief overview of the MRS principle for liver fat assessment and its application, and to summarize the current state of MRS study in comparison to other techniques.

Bariatric Surgery Outcomes in Patients with Previous Organ Transplant: Scoping Review and Analysis of the MBSAQIP

BACKGROUND

Obesity is a major risk factor for transplant. Laparoscopic bariatric surgery (LBS) offers transplant patient benefits including improved comorbidities, graft function, and longevity. We completed a scoping review and analyzed the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) to determine the risk-benefit profile of LBS after transplant. We also compared laparoscopic sleeve gastrectomy (LSG) to laparoscopic Roux-en-Y gastric bypass (LRYGB) following transplant.

METHODS

Univariate analysis determined between group differences with subgroup analysis comparing LSG versus LRYGB in transplant patients. Multivariable analysis assessed whether prior transplant was independently associated with major complications or mortality.

RESULTS

A total of 469 (0.1%) patients had previous transplant and had more comorbidities and more often underwent LSG. Operative time (93.9 min vs 83 min, p < 0.001) and length of stay were longer. Major complications were threefold higher in patients with a transplant history (9.6% vs 3.2%; p < 0.001. Previous transplant was the second greatest independent predictor for major complication (OR 2.14 [1.54-2.98], p = < 0.001) but was not predictive of death (OR 1.06 [0.14-8.13] p = 0.956). Amongst transplant patients, LRYGB demonstrated higher rates of leak (n = 1), VTE, AKI, unplanned intubation, and readmission.

CONCLUSIONS

The 30-day complication rate from LBS is three times higher amongst patients with a transplant. LSG is likely the best surgical approach. Despite risks, post-transplant patients incur important benefits from LBS. Surgeons must be aware of this risk-benefit profile when determining LBS candidacy.

Quantification of hepatic steatosis in histologic images by deep learning method

OBJECTIVE

To develop and test a novel method for automatic quantification of hepatic steatosis in histologic images based on the deep learning scheme designed to predict the fat ratio directly, which aims to improve accuracy in diagnosis of non-alcoholic fatty liver disease (NAFLD) with objective assessment of the severity of hepatic steatosis instead of subjective visual estimation.

MATERIALS AND METHODS

Thirty-six 8-week old New Zealand white rabbits of both sexes were fed with high-cholesterol, high-fat diet and sacrificed under deep anesthesia at various time points to obtain the pathological specimen. All rabbits were performed by multislice computed tomography for surveillance to measure density changes of liver parenchyma. A deep learning scheme using a convolutional neural network was developed to directly predict the liver fat ratio based on the pathological images. The average error value, standard deviation, and accuracy (error <5%) were evaluated and compared between the deep learning scheme and manual segmentation results. The Pearson's correlation coefficient was also calculated in this study.

RESULTS

The deep learning scheme performs successfully on rabbit liver histologic data, showing a high degree of accuracy and stability. The average error value, standard deviation, and accuracy (error <5%) were 3.21%, 4.02%, and 79.10% for the cropped images, 2.22%, 1.92%, and 88.34% for the original images, respectively. The strong positive correlation was also observed for cropped images (R = 0.9227) and original images (R = 0.9255) in comparison to labeled fat ratio.

CONCLUSIONS

This new deep learning scheme may aid in the quantification of steatosis in the liver and facilitate its treatment by providing an earlier clinical diagnosis.

Differential Diagnosis of a Patient with Lysosomal Acid Lipase Deficiency: A Case Report

BACKGROUND

We describe the differential diagnosis of an obese 12-year-old boy of Mexican origin who presented with a 6-year history of abnormal lipid profile and elevated liver transaminase levels.

METHODS

The patient underwent routine clinical testing, an abdominal ultrasound and, ultimately, a liver biopsy. Based on the histologic findings, a serum leukocyte lysosomal acid lipase (LAL) assay and DNA sequencing of the lipase A (LIPA) gene were performed.

RESULTS

Liver biopsy revealed diffuse microvesicular steatosis with clusters of foamy histiocytes in the lobules and portal areas. Our differential diagnosis included nonalcoholic fatty liver disease; medication-induced hepatotoxicity; glycogenic hepatopathy; medium-chain acyl coenzyme A dehydrogenase or long-chain acyl coenzyme A dehydrogenase deficiency; and lysosomal storage disorders, including Niemann-Pick disease and lysosomal acid lipase deficiency (LAL-D). Serum LAL activity was absent, and DNA sequencing confirmed homozygous mutation in LIPA.

CONCLUSIONS

Although it occurs rarely, LAL-D should be considered in the differential diagnosis of microvesicular steatosis for a timely diagnosis.

Bariatric Surgery and Liver Transplantation

Obesity is an important public health and medical concern in the United States. The rate of obesity has steadily risen for the past several decades. Obesity is associated with the development of nonalcoholic steatohepatitis, which is one of the leading indications for liver transplantation. After liver transplantation, recipients tend to gain weight and develop recurrent fatty liver. Over time, recurrent fatty liver may impact patient and graft survival. A bariatric surgical approach may be beneficial in select patients.

Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46; p = 0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65; p < 0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93; p = 0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95; p = 0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00; p = 0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match.

Severe alcoholic relapse after liver transplantation: What consequences on the graft? A study based on liver biopsies analysis

Alcoholic liver disease (ALD) is a major indication for liver transplantation (LT), but up to 20% of patients experience severe alcoholic relapse. The aims of this study were to evaluate the impact of severe alcoholic relapse on the graft (based on histological examination) and to identify predictive factors associated with recurrent alcoholic cirrhosis (RAC). From 1990 to 2010, 369 patients underwent LT for ALD at Edouard Herriot Hospital (Lyon, France) and survived more than 1 year. All patients who presented severe alcoholic relapse and histological follow-up were included. Liver biopsies were performed at 1 and 5 years and at every 5 years after LT, and when clinically indicated. The median follow-up after LT was 11 years (range, 3-18 years). Severe alcoholic relapse was observed in 73 (20%) of the 369 patients, from whom 56 patients with histological evaluation were included. RAC was diagnosed in 18 (32%) of the 56 patients included, which represents 5% of the 369 patients transplanted for ALD. The median delay between LT and RAC was 6 years (range, 3-10 years) and 4.5 years (range, 2-8 years) after severe alcoholic relapse. The median cumulated years of alcohol use before RAC was 3.5 years (range, 2-7 years). The cumulative risk for F4 fibrosis was 15% at 3 years, 32% at 5 years, and 54% at 10 years after severe alcoholic relapse. A young age at LT (≤50 years old) and an early onset of heavy drinking (within the first 3 years after LT) were associated with RAC. In conclusion, severe alcoholic relapse usually occurs in the first years after LT and is responsible for accelerated severe graft injury. Liver Transplantation 22 773-784 2016 AASLD.

Quantification of liver fat: A comprehensive review

Fat accumulation in the liver causes metabolic diseases such as obesity, hypertension, diabetes or dyslipidemia by affecting insulin resistance, and increasing the risk of cardiac complications and cardiovascular disease mortality. Fatty liver diseases are often reversible in their early stage; therefore, there is a recognized need to detect their presence and to assess its severity to recognize fat-related functional abnormalities in the liver. This is crucial in evaluating living liver donors prior to transplantation because fat content in the liver can change liver regeneration in the recipient and donor. There are several methods to diagnose fatty liver, measure the amount of fat, and to classify and stage liver diseases (e.g. hepatic steatosis, steatohepatitis, fibrosis and cirrhosis): biopsy (the gold-standard procedure), clinical (medical physics based) and image analysis (semi or fully automated approaches). Liver biopsy has many drawbacks: it is invasive, inappropriate for monitoring (i.e., repeated evaluation), and assessment of steatosis is somewhat subjective. Qualitative biomarkers are mostly insufficient for accurate detection since fat has to be quantified by a varying threshold to measure disease severity. Therefore, a quantitative biomarker is required for detection of steatosis, accurate measurement of severity of diseases, clinical decision-making, prognosis and longitudinal monitoring of therapy. This study presents a comprehensive review of both clinical and automated image analysis based approaches to quantify liver fat and evaluate fatty liver diseases from different medical imaging modalities.

Outcomes in liver transplantation: does sex matter?

A growing literature has highlighted important differences in transplant-related outcomes between men and women. In the United States there are fewer women than men on the liver transplant waitlist and women are two times less likely to receive a deceased or living-related liver transplant. Sex-based differences exist not only in waitlist but also in post-transplant outcomes, particularly in some specific liver diseases, such as hepatitis C. In the era of individualized medicine, recognition of these differences in the approach to pre and post-liver transplant care may impact short and long-term outcomes.