Heimbach, Julie K.

Background and Aims Reliance on exception points to prioritize children for liver transplantation (LT) stems from concerns that the Pediatric End‐Stage Liver Disease (PELD) score underestimates mortality. Renal dysfunction and serum sodium disturbances are negative prognosticators in adult LT candidates and various pediatric populations, but are not accounted for in PELD. We retrospectively evaluated the effect of these parameters in predicting 90‐day wait‐list death/deterioration among pediatric patients (<12 years) listed for isolated LT in the United States between February 2002 and June 2018. Approach and Results Among 4,765 patients, 2,303 (49.3%) were transplanted, and 231 (4.8%) died or deteriorated beyond transplantability within 90 days of listing. Estimated glomerular filtration rate (eGFR) (hazard ratio [HR] 1.09 per 5‐unit decrease, 95% confidence interval [CI] 1.06‐1.10) and dialysis (HR 7.24, 95% CI 3.57‐14.66) were univariate predictors of 90‐day death/deterioration (P < 0.001). The long‐term benefit of LT persisted in patients with renal dysfunction, with LT as a time‐dependent covariate conferring a 2.4‐fold and 17‐fold improvement in late survival among those with mild and moderate‐to‐severe dysfunction, respectively. Adjusting for PELD, sodium was a significant nonlinear predictor of outcome, with 90‐day death/deterioration risk increased at both extremes of sodium (HR 1.20 per 1‐unit decrease below 137 mmol/L, 95% CI 1.16‐1.23; HR per 1‐unit increase above 137 mmol/L 1.13, 95% CI 1.10‐1.17, P < 0.001). A multivariable model incorporating PELD, eGFR, dialysis, and sodium demonstrated improved performance and superior calibration in predicting wait‐list outcomes relative to the PELD score. Conclusions Listing eGFR, dialysis, and serum sodium are potent, independent predictors of 90‐day death/deterioration in pediatric LT candidates, capturing risk not accounted for by PELD. Incorporation of these variables into organ allocation systems may highlight patient subsets with previously underappreciated risk, augment ability of PELD to prioritize patients for transplantation, and ultimately mitigate reliance on nonstandard exceptions.

Background and Aims Alcoholic hepatitis (AH) is diagnosed by clinical criteria, although several objective scores facilitate risk stratification. Extracellular vesicles (EVs) have emerged as biomarkers for many diseases and are also implicated in the pathogenesis of AH. Therefore, we investigated whether plasma EV concentration and sphingolipid cargo could serve as diagnostic biomarkers for AH and inform prognosis to permit dynamic risk profiling of AH subjects. Approach and Results EVs were isolated and quantified from plasma samples from healthy controls, heavy drinkers, and subjects with end‐stage liver disease (ESLD) attributed to cholestatic liver diseases and nonalcoholic steatohepatitis, decompensated alcohol‐associated cirrhosis (AC), and AH. Sphingolipids were quantified by tandem mass spectroscopy. The median plasma EV concentration was significantly higher in AH subjects (5.38 × 1011/mL) compared to healthy controls (4.38 × 1010/mL; P < 0.0001), heavy drinkers (1.28 × 1011/mL; P < 0.0001), ESLD (5.35 × 1010/mL; P < 0.0001), and decompensated AC (9.2 × 1010/mL; P < 0.0001) disease controls. Among AH subjects, EV concentration correlated with Model for End‐Stage Liver Disease score. When EV counts were dichotomized at the median, survival probability for AH subjects at 90 days was 63.0% in the high‐EV group and 90.0% in the low‐EV group (log‐rank P value = 0.015). Interestingly, EV sphingolipid cargo was significantly enriched in AH when compared to healthy controls, heavy drinkers, ESLD, and decompensated AC (P = 0.0001). Multiple sphingolipids demonstrated good diagnostic and prognostic performance as biomarkers for AH. Conclusions Circulating EV concentration and sphingolipid cargo signature can be used in the diagnosis and differentiation of AH from heavy drinkers, decompensated AC, and other etiologies of ESLD and predict 90‐day survival permitting dynamic risk profiling.

Liver transplantation for cholangiocarcinoma has been an absolute contraindication worldwide due to poor results. However, in recent years and thanks to improvements of patient management and treatments of this cancer, this indication has been revisited. This consensus paper, approved by the International Liver Transplant Society, aims to provide a collection of expert opinions, consensus, and best practices surrounding liver transplantation for cholangiocarcinoma.

For patients with hepatocellular carcinoma (HCC) listed for liver transplantation (LT), United Network for Organ Sharing (UNOS) enacted policy changes in 2015 to improve equity between HCC and non‐HCC patients. We evaluated the impact of these changes on regional disparities in wait‐list dropout and LT. We included patients in the UNOS database listed with Model for End‐Stage Liver Disease HCC exceptions in long‐wait regions (LWRs), mid‐wait regions (MWRs), and short‐wait regions (SWRs) before these policy changes (era 1, January 1 to December 31, 2013) and after (era 2, October 7, 2015, to October 7, 2016). Cumulative incidence of wait‐list dropout and LT were evaluated using competing risk regression. Median time to LT increased by 3.6 months (3.1 to 6.7 months) in SWRs and 1.3 months (6.9 to 8.2 months) in MWRs (P < 0.001), with a slight decrease in LWRs (13.4 to 12.9 months; P = 0.02). The 2‐year cumulative incidence of dropout increased from 9.7% to 14.8% in SWRs (P = 0.03) and from 18.9% to 22.6% in MWRs (P = 0.18) but decreased in LWRs from 26.7% to 24.8% (P = 0.31). Factors predicting wait‐list dropout included listing in era 2 (hazard ratio [HR], 1.17), in LWRs (HR, 2.56), and in MWRs (HR, 1.91). Regional differences in wait‐list outcomes decreased with policy changes, but HCC patients in SWRs remain advantaged. Recent policy change may narrow these disparities.

Biliary complications (strictures and leaks) represent major limitations in living donor liver transplantation. Mesenchymal stem cells (MSCs) are a promising modality to prevent biliary complications because of immunosuppressive and angiogenic properties. Our goal was to evaluate the safety of adipose‐derived MSC delivery to biliary anastomoses in a porcine model. Secondary objectives were defining the optimal method of delivery (intraluminal versus extraluminal) and to investigate MSC engraftment, angiogenesis, and fibrosis. Pigs were divided into 3 groups. Animals underwent adipose collection, MSC isolation, and expansion. Two weeks later, animals underwent bile duct transection, reanastomosis, and stent insertion. Group 1 received plastic stents wrapped in unseeded Vicryl mesh. Group 2 received stents wrapped in MSC‐seeded mesh. Group 3 received unwrapped stents with the anastomosis immersed in an MSC suspension. Animals were killed 1 month after stent insertion when cholangiograms and biliary tissue were obtained. Serum was collected for liver biochemistries. Tissue was used for hematoxylin‐eosin and trichrome staining and immunohistochemistry for MSC markers (CD44 and CD34) and for a marker of neoangiogenesis (CD31). There were no intraoperative complications. One pig died on postoperative day 3 due to acute cholangitis. All others recovered without complications. Cholangiography demonstrated no biliary leaks and minimal luminal narrowing. Surviving animals exhibited no symptoms, abnormal liver biochemistries, or clinically significant biliary stricturing. Group 3 showed significantly greater CD44 and CD34 staining, indicating MSC engraftment. Fibrosis was reduced at the anastomotic site in group 3 based on trichrome stain. CD31 staining of group 3 was more pronounced, supporting enhanced neoangiogenesis. In conclusion, adipose‐derived MSCs were safely applied to biliary anastomoses. MSCs were locally engrafted within the bile duct and may have beneficial effects in terms of fibrosis and angiogenesis.