Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA.

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

High Neutrophil-Lymphocyte Ratio and Delta Neutrophil-Lymphocyte Ratio Are Associated with Increased Mortality in Patients with Hepatocellular Cancer.

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) has been proposed as a prognostic biomarker for cirrhosis and non-liver malignancies. We aimed to evaluate the prognostic value of NLR in a diverse cohort of patients with hepatocellular carcinoma (HCC). METHODS: We performed a retrospective study of patients diagnosed with HCC between 2008 and 2017 at two large US health systems. We used Cox proportional hazard and multivariable ordinal logistic regression models to identify factors associated with overall survival and response to first HCC treatment, respectively. Primary variables of interest were baseline NLR and delta NLR, defined as the difference between pre- and post-treatment NLR. RESULTS: Among 1019 HCC patients, baseline NLR was < 5 in 815 (80.0%) and ≥ 5 in 204 (20.0%). Patients with NLR ≥ 5 had a higher proportion of infiltrative tumors (36.2% vs 22.3%), macrovascular invasion (39.6% vs 25.5%), metastatic disease (20.6% vs 11.4%), and AFP > 200 ng/mL (45.6% vs 33.8%). Baseline NLR ≥ 5 was independently associated with higher mortality (median survival 4.3 vs 15.1 months; adjusted HR 1.70, 95%CI 1.41-2.06), with differences in survival consistent across BCLC stages. After adjusting for baseline covariates including NLR, delta NLR > 0.26 was also independently associated with increased mortality (HR 1.42, 95%CI 1.14-1.78). In a secondary analysis, high NLR was associated with lower odds of response to HCC treatment (20.2% vs 31.6%; adjusted OR 0.55, 95%CI 0.32-0.95). CONCLUSIONS: In a large Western cohort of patients with HCC, high baseline NLR and delta NLR were independent predictors of mortality. IMPACT: NLR is an inexpensive test that may be a useful component of future HCC prognostic models.

IDO1 metabolites activate ß-catenin signaling to promote cancer cell proliferation and colon tumorigenesis in mice.

BACKGROUND & AIMS: Indoleamine 2,3 dioxygenase-1 (IDO1) catabolizes tryptophan along the kynurenine pathway. Although IDO1 is expressed in inflamed and neoplastic epithelial cells of the colon, its role in colon tumorigenesis is not well understood. We used genetic and pharmacologic approaches to manipulate IDO1 activity in mice with colitis-associated cancer and human colon cancer cell lines. METHODS: C57Bl6 wild-type (control), IDO1-/-, Rag1-/-, and Rag1/IDO1 double-knockout mice were exposed to azoxymethane and dextran sodium sulfate to induce colitis and tumorigenesis. Colitis severity was assessed by measurements of disease activity, cytokine levels, and histologic analysis. In vitro experiments were conducted using HCT 116 and HT-29 human colon cancer cells. 1-methyl tryptophan and small interfering RNA were used to inhibit IDO1. Kynurenine pathway metabolites were used to simulate IDO1 activity. RESULTS: C57Bl6 mice given pharmacologic inhibitors of IDO1 and IDO1-/- mice had lower tumor burdens and reduced proliferation in the neoplastic epithelium after administration of dextran sodium sulfate and azoxymethane than control mice. These reductions also were observed in Rag1/IDO1 double-knockout mice compared with Rag1-/- mice (which lack mature adaptive immunity). In human colon cancer cells, blockade of IDO1 activity reduced nuclear and activated ß-catenin, transcription of its target genes (cyclin D1 and Axin2), and, ultimately, proliferation. Exogenous administration of IDO1 pathway metabolites kynurenine and quinolinic acid led to activation of ß-catenin and proliferation of human colon cancer cells, and increased tumor growth in mice. CONCLUSIONS: IDO1, which catabolizes tryptophan, promotes colitis-associated tumorigenesis in mice, independent of its ability to limit T-cell-mediated immune surveillance. The epithelial cell-autonomous survival advantage provided by IDO1 to colon epithelial cells indicate its potential as a therapeutic target.

Cysteine sulfinic acid decarboxylase regulation: A role for farnesoid X receptor and small heterodimer partner in murine hepatic taurine metabolism.

AIM: Bile acid synthesis is regulated by nuclear receptors including farnesoid X receptor (FXR) and small heterodimer partner (SHP), and by fibroblast growth factor 15/19 (FGF15/19). We hypothesized that hepatic cysteine sulfinic acid decarboxylase (CSAD) (a key enzyme in taurine synthesis) is regulated by bile acids (BA). The aim of this study was to investigate CSAD regulation by BA dependent regulatory mechanisms. METHODS: Mice were fed a control diet or a diet supplemented with either 0.5% cholate or 2% cholestyramine. To study BA dependent pathways, we utilized GW4064 (FXR agonist), FGF19 or T-0901317 (liver X receptor [LXR] agonist) and Shp-/- mice. Tissue mRNA was determined by quantitative reverse transcription polymerase chain reaction. Amino acids were measured by high-performance liquid chromatography. RESULTS: Mice supplemented with dietary cholate exhibited reduced hepatic CSAD mRNA while those receiving cholestyramine exhibited increased mRNA. Activation of FXR suppressed CSAD mRNA expression whereas CSAD expression was increased in Shp-/- mice. Hepatic hypotaurine concentration (the product of CSAD) was higher in Shp-/- mice with a corresponding increase in serum taurine conjugated BA. FGF19 administration suppressed hepatic cholesterol 7-α-hydroxylase (CYP7A1) mRNA but did not change CSAD mRNA expression. LXR activation induced CYP7A1 mRNA yet failed to induce CSAD mRNA expression. CONCLUSION: BA regulate CSAD mRNA expression in a feedback fashion via mechanisms involving SHP and FXR but not FGF15/19 or LXR. These findings implicate BA as regulators of CSAD mRNA via mechanisms shared with CYP7A1.

Liver volume in the cirrhotic patient: does size matter?

BACKGROUND: While it is established that cirrhosis results in a decrease in liver volume (LV), whether LV itself predicts patient survival is unknown. We hypothesize that estimated LV is an important prognostic indicator in patients with cirrhosis. METHODS: Data was gathered retrospectively from consecutive patients evaluated for a liver transplant from January 2001 to June 2006. Of 500 patients identified, 323 patients met both inclusion and exclusion criteria. LV per ideal body weight (IBW) was used to correct for body size, and LV/IBW was stratified by median split for survival analyses. Patients were classified into one of three clinical groups: hepatocellular disease (n = 229), cholestatic disease (n = 56), and miscellaneous (n = 38). One of three possible clinical outcomes (survival, liver transplantation, or death) was recorded during the 5-year follow-up, the latter two grouped together as "transplant/death." RESULTS: Transplant/death occurred in 283 (88 %) subjects. Overall, there was a significant increase in transplant/death in those with lower LV/IBW (χ(2) = 5.27, p = 0.022). When considering the subset with hepatocellular disease, lower LV/IBW was a robust predictor of transplant/death (χ(2) = 9.62, p = 0.002). In multivariate analyses, the LV/IBW trended toward predicting transplant/death (ExpB = 0.943, p = 0.053) independent of Model for End stage Liver Disease (MELD) (ExpB = 1.13, p = 0.001). DISCUSSION: LV has important predictive value in patients with cirrhosis from hepatocellular disease. This observation appears to be independent of MELD, suggesting LV may impart important prognostic information that is not captured by the MELD score alone. Thus, LV may serve as an important adjunct to the MELD score in patients with hepatocellular disease.

Therapeutic RNA manipulation in liver disease.

Posttranscriptional regulation of gene expression is increasingly recognized as a model for inherited and acquired disease. Recent work has expanded understanding of the range of mechanisms that regulate several of these distinct steps, including messenger RNA (mRNA) splicing, trafficking, and/or stability. Each of these pathways is implicated in disease pathogenesis, and each represents important avenues for therapeutic intervention. This review summarizes important mechanisms controlling mRNA processing and the regulation of mRNA degradation, including the role of microRNAs and RNA binding proteins. These pathways provide important opportunities for therapeutic targeting directed at splicing and degradation in order to attenuate genetic defects in RNA metabolism. We will highlight developments in vector development and validation for therapeutic manipulation of mRNA expression with a focus on potential applications in metabolic and immunomediated liver disease.

Decreased expression of cholesterol 7alpha-hydroxylase and altered bile acid metabolism in Apobec-1-/- mice lead to increased gallstone susceptibility.

Quantitative trait mapping in mice identified a susceptibility locus for gallstones (Lith6) spanning the Apobec-1 locus, the structural gene encoding the RNA-specific cytidine deaminase responsible for production of apolipoprotein B48 in mammalian small intestine and rodent liver. This observation prompted us to compare dietary gallstone susceptibility in Apobec-1(-/-) mice and congenic C57BL/6 wild type controls. When fed a lithogenic diet (LD) for 2 weeks, 90% Apobec-1(-/-) mice developed solid gallstones in comparison with 16% wild type controls. LD-fed Apobec-1(-/-) mice demonstrated increased biliary cholesterol secretion as well as increased cholesterol saturation and bile acid hydrophobicity indices. These changes occurred despite a relative decrease in cholesterol absorption in LD-fed Apobec-1(-/-) mice. Among the possible mechanisms to account for this phenotype, expression of Cyp7a1 mRNA and protein were significantly decreased in chow-fed Apobec-1(-/-) mice, decreasing further in LD-fed animals. Cyp7a1 transcription in hepatocyte nuclei, however, was unchanged in Apobec-1(-/-) mice, excluding transcriptional repression as a potential mechanism for decreased Cyp7a1 expression. We demonstrated that APOBEC-1 binds to AU-rich regions of the 3'-untranslated region of the Cyp7a1 transcript, containing the UUUN(A/U)U consensus motif, using both UV cross-linking to recombinant APOBEC-1 and in vivo RNA co-immunoprecipitation. In vivo Apobec-1-dependent modulation of Cyp7a1 expression was further confirmed following adenovirus-Apobec-1 administration to chow-fed Apobec-1(-/-) mice, which rescued Cyp7a1 gene expression. Taken together, the findings suggest that the AU-rich RNA binding-protein Apobec-1 mediates post-transcriptional regulation of murine Cyp7a1 expression and influences susceptibility to diet-induced gallstone formation.

Loss of nuclear receptor SHP impairs but does not eliminate negative feedback regulation of bile acid synthesis.

The in vivo role of the nuclear receptor SHP in feedback regulation of bile acid synthesis was examined. Loss of SHP in mice caused abnormal accumulation and increased synthesis of bile acids due to derepression of rate-limiting CYP7A1 and CYP8B1 hydroxylase enzymes in the biosynthetic pathway. Dietary bile acids induced liver damage and restored feedback regulation. A synthetic agonist of the nuclear receptor FXR was not hepatotoxic and had no regulatory effects. Reduction of the bile acid pool with cholestyramine enhanced CYP7A1 and CYP8B1 expression. We conclude that input from three negative regulatory pathways controls bile acid synthesis. One is mediated by SHP, and two are SHP independent and invoked by liver damage and changes in bile acid pool size.

More Than a Rash: Recurrent Hepatocellular Carcinoma After Liver Transplantation.

Recurrent hepatocellular carcinoma (HCC) after liver transplant is uncommon in patients who have favorable pretransplant characteristics. We present a 56-year-old man with a history of liver transplant 8 weeks prior for hepatitis C cirrhosis and HCC who presented for shortness of breath. He was found to have a microangiopathic hemolytic anemia and an erythematous, nodular skin rash on his left lower abdomen. Biopsy of the skin rash would demonstrate metastatic HCC, determined to be the cause of hemolysis as well. Recurrent malignancy should be considered in patients with a history of HCC who present with new, unexplained skin nodules.

Intestine-Specific Mttp Deletion Increases the Severity of Experimental Colitis and Leads to Greater Tumor Burden in a Model of Colitis Associated Cancer.

BACKGROUND: Gut derived lipid factors have been implicated in systemic injury and inflammation but the precise pathways involved are unknown. In addition, dietary fat intake and obesity are independent risk factors for the development of colorectal cancer. Here we studied the severity of experimental colitis and the development of colitis associated cancer (CAC) in mice with an inducible block in chylomicron secretion and fat malabsorption, following intestine-specific deletion of microsomal triglyceride transfer protein (Mttp-IKO). METHODOLOGY/PRINCIPAL FINDINGS: Mttp-IKO mice exhibited more severe injury with ∼90% mortality following dextran sodium sulfate (DSS) induced colitis, compared to <20% in controls. Intestinal permeability was increased in Mttp-IKO mice compared to controls, both at baseline and after DSS administration, in association with increased circulating levels of TNFα. DSS treatment increased colonic mRNA expression of IL-1ß and IL-17A as well as inflammasome expression in both genotypes, but the abundance of TNFα was selectively increased in DSS treated Mttp-IKO mice. There was a 2-fold increase in colonic tumor burden in Mttp-IKO mice following azoxymethane/DSS treatment, which was associated with increased colonic inflammation as well as alterations in cytokine expression. To examine the pathways by which alterations in fatty acid abundance might interact with cytokine signaling to regulate colonic epithelial growth, we used primary murine myofibroblasts to demonstrate that palmitate induced expression of amphiregulin and epiregulin and augmented the increase in both of these growth mediators when added to IL-1ßor to TNFα. CONCLUSIONS: These studies demonstrate that Mttp-IKO mice, despite absorbing virtually no dietary fat, exhibit augmented fatty acid dependent signaling that in turn exacerbates colonic injury and increases tumor formation.

MicroRNAs and liver disease.

Posttranscriptional regulation of gene expression is now recognized as an important contributor to disease pathogenesis, whose mechanisms include alterations in the function of stability and translational elements within both coding and noncoding regions of messenger RNA. A major component in this regulatory paradigm is the binding both to RNA stability as well as to translational control elements by microRNAs (miRNAs). miRNAs are noncoding endogenously transcribed RNAs that undergo a well-characterized series of processing steps that generate short single-stranded (∼20-22) RNA fragments that bind to complementary regions within a range of targets and in turn lead to mRNA degradation or attenuated translation as a result of trafficking to processing bodies. This article will highlight selected advances in the role of miRNAs in liver disease including nonalcoholic fatty liver disease, viral hepatitis, and hepatocellular carcinoma and will briefly discuss the utility of miRNAs as biomarkers of liver injury and neoplasia.

Pancreatitis following Olanzapine Therapy: A Report of Three Cases.

CONTEXT: Atypical antipsychotic agents (clozapine, olanzapine) have been linked to metabolic effects and acute pancreatitis. CASE REPORT: We reviewed the inpatient and outpatient records of three patients who developed acute pancreatitis while being treated with olanzapine. The mean age of the patients was 37.7 years (range 18-54 years, 2 female, 1 male). No alternative cause of acute pancreatitis was found in two of the three patients. In the remaining patient, olanzapine may have contributed to acute pancreatitis in the setting of hypertriglyceridemia. Olanzapine was discontinued in all instances. Over a mean follow-up of 14 months, one patient has had a relapsing course, but the remaining two patients have been symptom free without recurrence of acute pancreatitis. CONCLUSIONS: Our case series adds further support to the potential link between olanzapine use and acute pancreatitis. Close monitoring of metabolic parameters is suggested in patients treated with olanzapine. Alternative antipsychotic agents should be considered in patients at high risk for pancreatitis.