Watt, Kymberly

ObjectivesMetabolic dysfunction‐associated steatotic liver disease (MASLD) is the most prevalent liver disorder in Western countries, with approximately 20%–30% of the MASLD patients progressing to severe stages. There is an urgent need for noninvasive, cost‐effective, widely accessible, and precise biomarkers to evaluate liver steatosis. This study aims to assess and compare the diagnostic performance of a novel reference frequency method‐based ultrasound attenuation coefficient estimation (ACE) in both fundamental (RFM‐ACE‐FI) and harmonic (RFM‐ACE‐HI) imaging for detecting and grading liver steatosis.MethodsAn Institutional Review Board‐approved prospective study was carried out between December 2018 and October 2022. A total number of 130 subjects were enrolled in the study. The correlation between RFM‐ACE‐HI values and magnetic resonance imaging proton density fat fraction (MRI‐PDFF), as well as between RFM‐ACE‐FI values and MRI‐PDFF were calculated. The diagnostic performance of RFM‐ACE‐FI and RFM‐ACE‐HI was evaluated using receiver operating characteristic (ROC) curve analysis, as compared to MRI‐PDFF. The reproducibility of RFM‐ACE‐HI was assessed by interobserver agreement between two sonographers.ResultsA strong correlation was observed between RFM‐ACE‐HI and MRI‐PDFF, with R = 0.88 (95% confidence interval [CI]: 0.83–0.92; P < .001), while the correlation between RFM‐ACE‐FI and MRI‐PDFF was R = 0.65 (95% CI: 0.50–0.76; P < .001). The area under the ROC (AUROC) curve for RFM‐ACE‐HI in staging liver steatosis grades of S ≥ 1 and S ≥ 2 was 0.97 (95% CI: 0.91–0.99; P < .001) and 0.98 (95% CI: 0.93–1.00; P < .001), respectively, and 0.76 (95% CI: 0.65–0.85) and 0.80 (95% CI: 0.70–0.88) for RFM‐ACE‐FI, respectively. Great reproducibility was achieved for RFM‐ACE‐HI, with an interobserver agreement of R = 0.97 (95% CI: 0.94–0.99; P < .001).ConclusionsThe novel RFM‐ACE‐HI method offered high liver steatosis diagnostic accuracy and reproducibility, which has important clinical implications for early disease intervention and treatment evaluation.

Background. Surgical-site infections (SSIs) are common in liver transplant recipients. The optimal SSI antimicrobial prophylaxis agent and duration are not established. We aimed to explore risk factors for SSIs after transplant, with a particular interest in the impact of perioperative antibiotic regimen on the development of SSIs. Methods. Retrospective study of adults undergoing liver transplant across 3 transplant programs between January 1, 2020, and June 01, 2021. Results. Of 557 patients included in the study, 32 (5.7%) were infected or colonized with a multidrug-resistant organism (MDRO) within 1 y before liver transplant. Narrow-spectrum SSI prophylaxis with ceftriaxone or cefazolin alone was administered in 488 of 577 patients (87.6%); the remaining 69 patients (12.4%) received broad-spectrum prophylaxis with vancomycin and aztreonam (n = 40), piperacillin–tazobactam (n = 11), carbapenems (n = 8), ceftriaxone and another antibiotic (n = 7), and others. Patients with pretransplant MDRO were more likely to receive broad-spectrum coverage than those without pretransplant MDROs (28.1% versus 11.4%, P = 0.005). SSIs were identified in 40 patients (7.2%); 25 (62.5%) were organ–space infections, 3 (7.5%) were deep incisional infections, and 12 (30.0%) were superficial incisional infections. The median time from liver transplant to SSIs was 14 d (interquartile range, 10–20.2). MDROs were identified in 12 SSIs (30%). Multivariable analysis revealed no significant association between antimicrobial spectrum and risk of SSIs (P = 0.5), whereas surgical leak (P<0.001) and reoperation (P = 0.017) were independently associated with increased risk of SSIs. SSIs were not significantly associated with composite risk of death or liver allograft failure. Conclusions. The spectrum of antimicrobial prophylaxis did not impact the development of SSIs in liver transplant recipients.

Background. When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes. Methods. A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference. Results. The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed. Conclusions. The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Background: Direct-acting antivirals (DAA) are highly effective for the treatment of hepatitis C (HCV), although there are limited data on the safety and efficacy of DAA therapy in hepatitis C-positive individuals awaiting liver transplantation for hepatocellular carcinoma (HCC). Methods: We conducted a retrospective cohort study of HCV-positive patients who underwent liver transplantation for HCC at 3 liver transplant centers across the United States from 2014 to 2017 with follow-up to July 2018. Transplant recipients who received DAA before transplant were compared with those who did not (DAA naive) for posttransplant HCC recurrence rate, sustained virological response (SVR), allograft failure, and death using Kaplan-Meier analysis and Cox proportional hazard models. Results: A total of 171 HCV-HCC transplant recipients (99 pretransplant DAA; 72 DAA naive controls) were included, with a median follow-up of 24 months. The overall posttransplant HCC recurrence rate was 9% (15/171). Pretransplant DAA was not associated with HCC recurrence (5% versus 14%; P = 0.07), graft failure (7% versus 3%; P = 0.21), or death (12% versus 19%; P = 0.19) as compared with DAA naive patients. SVR rates were significantly lower (P < 0.01) with pretransplant DAA (75%, 39/52) than posttransplant DAA (97%, 59/61) therapies. Those who received pretransplant DAA and those who did not were not statistically different in age, gender, alpha fetal protein levels, model for end-stage liver disease scores, or transplant wait time. Conclusions: Pretransplant DAA for HCV was not associated with an increased risk of posttransplant HCC recurrence, though pretransplant DAA had lower efficacy than posttransplant DAA in HCV-HCC transplant recipients.

Background. The role of MZ phenotype of α 1 antitrypsin (α1AT) deficiency as a potential cofactor in advanced liver disease arising from other primary causes is not widely understood. In the general population, MZ phenotype accounts for 2%–4% in Europe and 2%–7.1% in North America. The aim of this study was to determine the prevalence of the MZ phenotype among various causes of cirrhosis in the United States in the modern era and its impact on pulmonary function before and after liver transplantation. Methods. This retrospective study included adult patients with cirrhosis who underwent liver transplantation at Mayo Clinic. Participants’ data including pathogenesis of cirrhosis, model for end-stage liver disease-Na score, α1AT phenotype, liver decompensation events, and pulmonary outcomes was determined by retrospective review of the liver transplantation database. Results. One hundred thirty of 1341 adult patients with cirrhosis (9.7%) were α1AT MZ carriers. When comparing the distribution of protease inhibitor (PI) MZ among different pathogenesis, the prevalence of MZ was significantly increased in nonalcoholic steatohepatitis (NASH), alcoholic liver disease (ALD), and cryptogenic cirrhosis compared with other causes. Thirty-seven of 171 with NASH (22%), 37 of 187 with ALD (20%), and 9 of 39 with cryptogenic cirrhosis (23.1%) were identified as PI MZ, while in other subgroups; we detected 18 of 320 with viral hepatitis, and 11 of 339 with primary biliary cholangitis/primary sclerosing cholangitis. Also, MZ patients were more likely to develop preoperative chronic obstructive lung disease, and postoperative pulmonary hypertension and pulmonary embolism than MM patients. Conclusions. The rates of preoperative and postoperative pulmonary complications were found to be higher in PI MZ patients than in PI MM patients. The MZ phenotype was significantly enriched in NASH, ALD, and cryptogenic cirrhosis.

Machine learning (ML) utilizes artificial intelligence to generate predictive models efficiently and more effectively than conventional methods through detection of hidden patterns within large data sets. With this in mind, there are several areas within hepatology where these methods can be applied. In this review, we examine the literature pertaining to machine learning in hepatology and liver transplant medicine. We provide an overview of the strengths and limitations of ML tools and their potential applications to both clinical and molecular data in hepatology. ML has been applied to various types of data in liver disease research, including clinical, demographic, molecular, radiological, and pathological data. We anticipate that use of ML tools to generate predictive algorithms will change the face of clinical practice in hepatology and transplantation. This review will provide readers with the opportunity to learn about the ML tools available and potential applications to questions of interest in hepatology.

SummaryBackgroundLipotoxicity leading to excessive caspase‐mediated apoptosis and inflammation is believed to drive liver damage in NAFLD. Emricasan is a pan‐caspase inhibitor that decreased serum ALT and apoptotic and inflammatory markers in subjects with chronic hepatitis.AimsTo assess whether 28 days of emricasan would reduce elevated levels of serum ALT, AST, cleaved cytokeratin‐18, full‐length cytokeratin‐18, and caspase 3/7 in subjects with NAFLD and raised aminotransferases.MethodsDouble‐blind, placebo‐controlled, office‐practice study assessed the efficacy, safety, and tolerability of emricasan in subjects with NAFLD and ALT levels ≥1.5 x ULN during screening. Subjects were randomised to emricasan 25 mg twice daily or matching placebo. Subjects with cirrhosis and other causes for raised aminotransferases were excluded. The primary endpoint was the change in ALT at day 28 in the emricasan group vs placebo.Results38 subjects were randomised, 19 each to emricasan or placebo. Baseline disease factors were well balanced except for lower median ALT values in emricasan subjects. Three subjects randomised to placebo discontinued prior to day 28. ALT values decreased significantly in emricasan‐treated subjects vs placebo at days 7 (P < 0.0001) and 28 (P = 0.02). cCK18 (day 7), flCK18 (days 7 and 28), and caspase 3/7 (day 7) were also significantly decreased in emricasan‐treated subjects vs placebo. Emricasan treatment was generally safe and well tolerated.ConclusionsEmricasan decreased ALT and biomarkers in subjects with NAFLD and raised aminotransferases after 28 days. These results support the further development of emricasan in patients with NAFLD. Trial registration: ClinicalTrials.gov, Identifier: NCT02077374.

Introduction: Dobutamine stress echocardiography (DSE) is frequently used to screen for obstructive coronary artery disease in the pre-liver transplant evaluation. Although atropine is a commonly used adjunctive medication, no study has evaluated its side effect profile in patients with end-stage liver disease (ESLD). Research Question: What is the safety of atropine in candidates undergoing pre-liver transplant evaluation when atropine is used in stress testing? Design: This multicenter, prospective study enrolled patients over a 6-month period undergoing pre-liver transplant evaluation. Each patient completed a questionnaire assessing anticholinergic-related symptoms within 24 hours of testing and 48 hours following. Comparisons were made among patients receiving any atropine dose versus those who did not and among patients receiving at least 1 mg atropine and those receiving less/none. Results: Forty patients were evaluated, and 32 (80%) had adjunctive atropine administered. No differences in clinical characteristics were noted. In comparisons among patients receiving any dose of atropine with those who did not, questionnaire results indicated a higher rate of nausea prior to testing and higher overall symptom severity following testing in patients not receiving atropine. In comparisons among patients receiving less than 1 mg atropine with those receiving at least 1 mg atropine, no difference in pre- or posttesting questionnaire responses was present. No patient in the study required reversal agents or hospitalization within 7 days of testing. Conclusions: Atropine, a hepatically metabolized medication, did not predispose patients with ESLD to an increased symptom burden, and clinical outcomes related to DSE were unaffected.