Indeterminate etiology of acute liver failure in North America: Less common, still grave prognosis.

BACKGROUND: The etiology of acute liver failure (ALF) remains one of the most important factors in determining prognosis and predicting outcomes. In a significant proportion of ALF cases, however, the etiology remains unknown and is categorized as indeterminate ALF (IND-ALF). In this study, we summarize findings from patients with IND-ALF from 32 transplant centers across the United States, and we compare laboratory, prognostic, and outcome data for patients with IND-ALF. METHODS: Between 1998 and 2019, 3364 adult patients with ALF or acute liver injury (ALI) from 32 liver transplant centers were enrolled in the ALFSG registry. The primary clinical outcome of interest was 21-day transplant-free survival (TFS). RESULTS: Of the 3364 patients enrolled in the ALFSG registry, 3.4 % (n = 114) were adjudicated as true indeterminate. On multivariate analysis, patients with a lower bilirubin, lower INR, lack of use of mechanical ventilation and no clinical features of coma at baseline had a higher odds ratio of transplant free survival. The number of deaths were similar between patients with true-IND ALF versus patients with indeterminable ALF (29.8% vs. 27.2%), with almost half of the patients requiring liver transplant (42.1% vs. 45.7%). CONCLUSION: We illustrate the poor prognoses that true-IND-ALF and indeterminable ALF carry and the need for emergency liver transplantation in most cases.

Autoimmune hepatitis presenting as acute liver failure: A 20-year retrospective review of North America.

Autoimmune hepatitis is a common cause of acute liver failure. Treatment includes steroids for acute liver injury and liver transplantation in those who fail to respond or develop acute liver failure. The aim of this study is to further characterize acute liver failure secondary to autoimmune hepatitis and identify variables that predict 21-day transplant-free survival. This study included adults hospitalized with acute liver failure enrolled in the Acute Liver Failure Study Group Registry between 1998 and 2019 from 32 centers within the US. The etiology of all cases was reviewed by the Adjudication Committee, and all cases identified as autoimmune hepatitis were included. Acute liver injury was defined as an INR ≥2.0 without encephalopathy and acute liver failure as INR ≥ 1.5 with encephalopathy. Laboratory and clinical data were reviewed. Variables significantly associated with 21-day transplant-free survival were used to develop a multivariable logistic regression model.  A total of 193 cases of acute liver failure secondary to autoimmune hepatitis were identified and reviewed. There were 161 patients (83.4%) diagnosed with acute liver failure on enrollment, and 32 (16.6%) developed acute liver failure during hospitalization. At 21 days, 115 (59.6%) underwent liver transplantation, 28 (14.5%) had transplant-free survival, and 46 (23.8%) died before liver transplantation. Higher admission values of bilirubin, INR, and coma grade were associated with worse outcomes. A prognostic index incorporating bilirubin, INR, coma grade, and platelet count had a concordance statistic of 0.84. Acute liver failure secondary to autoimmune hepatitis is associated with a high short-term mortality. We developed a model specifically for autoimmune hepatitis that may be helpful in predicting 21-day transplant-free survival and early identification of patients in need of expedited liver transplant evaluation.

Prognostic Value of the 13 C-Methacetin Breath Test in Adults with Acute Liver Failure and Non-acetaminophen Acute Liver Injury.

BACKGROUND AND AIMS: The 13 C-methacetin breath test (MBT) is a noninvasive, quantitative hepatic metabolic function test. The aim of this prospective, multicenter study was to determine the utility of initial and serial 13 C-MBT in predicting 21-day outcomes in adults with acute liver failure (ALF) and non-acetaminophen acute liver injury (ALI). APPROACH AND RESULTS: The 13 C-MBT BreathID device (Exalenz Biosciences, Ltd.) provided the percent dose recovery (PDR) for a duration of 60 minutes after administration of 13 C-methacetin solution as the change in exhaled 13 CO2 /12 CO2 compared with pre-ingestion ratio on study days 1, 2, 3, 5, and 7. Results were correlated with 21-day transplant-free survival and other prognostic indices. A total of 280 subjects were screened for enrollment between May 2016 and August 2019. Median age of the 62 enrolled patients with adequate data was 43 years, 79% were Caucasian, 76% had ALF with the remaining 24% having ALI. The mean PDR peak on day 1 or day 2 was significantly lower in nonsurvivors compared with transplant-free survivors (2.3%/hour vs. 9.1%/hour; P < 0.0001). In addition, serial PDR peaks were consistently lower in nonsurvivors versus survivors (P < 0.0001). The area under the receiver operating characteristic curve (AUROC) of the 13 C-MBT in the combined cohort was 0.88 (95% CI: 0.79-0.97) and higher than that provided by King's College (AUROC = 0.70) and Model for End-Stage Liver Disease scores (AUROC = 0.83). The 13 C-MBT was well tolerated with only two gastrointestinal adverse events reported. CONCLUSIONS: The 13 C-MBT is a promising tool to estimate the likelihood of hepatic recovery in patients with ALF and ALI. Use of the PDR peak data from the 13 C-MBT point-of-care test may assist with medical decision making and help avoid unnecessary transplantation in critically ill patients with ALF and ALI.

Coagulopathy, Bleeding Events, and Outcome According to Rotational Thromboelastometry in Patients With Acute Liver Injury/Failure.

BACKGROUND AND AIMS: Patients with acute liver injury or failure (ALI/ALF) experience bleeding complications uncommonly despite an abnormal hemostatic profile. Rotational thromboelastometry (ROTEM), which assesses clot formation in whole blood, was used to determine the nature of abnormal hemostasis and whether it contributes to bleeding events, illness severity, or survival. APPROACH AND RESULTS: A total of 200 patients were recruited from sites of the ALF Study Group. Blood collected daily for up to 5 days was analyzed using ROTEM delta devices. Consistent with standard laboratory evidence of hypocoagulability (median international normalized ratio = 2.9 and platelet count = 144 × 109 /L), patients frequently exhibited ROTEM parameters outside the normal range (73% and 62% had abnormalities in clot formation from extrinsic and intrinsic clotting cascades, respectively); however, measures of clot stability were generally normal. Eighteen patients (9%) experienced bleeding events, in whom clot initiation, assembly, and firmness were more severely deranged than patients without bleeding. Abnormal ROTEM parameters were more frequently observed in patients with non-acetaminophen ALI/ALF than those with acetaminophen ALI/ALF (clot initiation [P < 0.001], assembly [P = 0.02], firmness at 10 minutes [P = 0.05], and maximal firmness [P = 0.06]). Patients with more severe systemic complications (high-grade hepatic encephalopathy and need for renal replacement therapy) also had a higher incidence of abnormal ROTEM parameters. Finally, more hypocoagulable ROTEM parameters (clot initiation (P = 0.005), stiffness at 10 minutes (P = 0.05), and maximal stiffness by fibrin assembly (P = 0.004)) were observed in patients who died or underwent liver transplantation than those who survived with their native liver. CONCLUSIONS: In patients with ALI/ALF, abnormal ROTEM parameters are frequent and proportional to disease severity. Whether the increased bleeding risk associated with abnormal ROTEM indicates hemostatic failure or is a proxy for disease severity requires additional study.

An Analysis of the Clinical, Laboratory, and Histological Features of Striped, Punctate, and Nodular Gastric Antral Vascular Ectasia.

BACKGROUND: Gastric antral vascular ectasia (GAVE) commonly presents as linear striped ("watermelon stomach") or punctate phenotypes, to which a newly discovered nodular form was recently added. AIMS: We performed a retrospective cohort study to detail and compare the clinical and histological characteristics of major GAVE phenotypes. METHODS: In 136 GAVE patients (tertiary care ambulatory and inpatient, median age 61.3 years, 73 men, and 63 women), clinical and laboratory results were recorded, with comorbidities, endoscopy indications, and complications of cirrhosis. In 74 patients, GAVE histopathology was cataloged by a pathologist masked to endoscopy results. RESULTS: Median age 61.3 years, 73 men, and 63 women. GAVE phenotypes were: linear striped-62 (46%), punctate-32 (24%), and nodular-41 (30%). Endoscopy was commonly performed for variceal screening in linear striped (45%) and nodular (34%) GAVE and for gastrointestinal bleeding in punctate (41%) and nodular (29%) GAVE, respectively. Of 89 cirrhotic patients, 37.5% each had linear striped or nodular GAVE, 24.7% had punctate forms (p = 0.03). Child-Turcotte-Pugh and Model for End-Stage Liver Disease scores were similar among phenotypes. Histologically, reactive epithelial hyperplasia and vascular ectasia were universal; smooth muscle proliferation was more common and consistent (78-86%) than microvascular thrombi (27-59%) and fibrohyalinosis (18-53%), which each varied with phenotype. CONCLUSIONS: Nodular GAVE is a gastric mucosal abnormality that is similar to the linear striped and punctate phenotypes, yet has distinct clinical and histological features. Increased awareness of nodular GAVE by endoscopists is needed to avoid its misdiagnosis as nonspecific antral nodules.

Relationship of Abnormal Chromatographic Pattern for Carbohydrate-Deficient Transferrin with Severe Liver Disease.

AIMS: Serum carbohydrate-deficient transferrin (CDT) is a validated test for chronic heavy alcohol drinking, but CDT abnormalities have been associated with liver disease, limiting its use in these patients. We report here on the association between poor chromatographic resolution of disialotransferrin from trisialotransferrin (the so-called 'di-tri bridging') and liver disease severity and etiology. METHODS: Subjects were patients in whom detailed clinical data, including histology results, were available on their existing liver diseases (n=139). Percent disialo-CDT (%dCDT) was measured by high-performance liquid chromatography, and the risks for di-tri bridging associated with cirrhosis, with and without adjustment for alcohol use and alcohol-related liver disease, were estimated. RESULTS: Di-tri bridging was present in 22/73 (30%) cirrhotic subjects and 7/66 (11%) non-cirrhotic subjects. The unadjusted risk for di-tri bridging in cirrhotics relative to non-cirrhotics was 3.6 (95% confidence interval 1.4-9.2). Adjustment for alcohol-related liver disease and current drinking had little effect on this estimate (adjusted odds ratio 3.4), and neither alcohol-related liver disease nor current drinking were independently associated with di-tri bridging after accounting for the effect of cirrhosis. CONCLUSIONS: The presence of di-tri bridging was associated with cirrhosis in individuals with both alcohol-related and non-alcoholic liver disease, although most cirrhotic subjects did not exhibit di-tri bridging. When di-tri bridging is seen in individuals being tested for chronic heavy drinking, investigation for cirrhosis should be considered. SHORT SUMMARY: There are known liver-disease-associated abnormalities in CDT. In this study, we found that such abnormalities were strongly associated with cirrhosis rather than less-advanced disease, but were only clinically evident in 30% of cirrhotics. Abnormalities also occurred in severe hepatitis without cirrhosis and were not specific for liver disease etiology.

An Immunoassay to Rapidly Measure Acetaminophen Protein Adducts Accurately Identifies Patients With Acute Liver Injury or Failure.

BACKGROUND & AIMS: A rapid and reliable point-of-care assay to detect acetaminophen protein adducts in the serum of patients with acute liver injury could improve diagnosis and management. AcetaSTAT is a competitive immunoassay used to measure acetaminophen protein adducts formed by toxic metabolites in serum samples from patients. We compared the accuracy of AcetaSTAT vs high-pressure liquid chromatography with electrochemical detection (HPLC-EC; a sensitive and specific quantitative analytic assay) to detect acetaminophen protein adducts. METHODS: We collected serum samples from 19 healthy individuals (no liver injury, no recent acetaminophen use), 29 patients without acetaminophen-associated acute liver injury, and 33 patients with acetaminophen-associated acute liver injury participating in the Acute Liver Failure Study Group registry. Each serum sample was analyzed by AcetaSTAT (reported as test band amplitude) and HPLC-EC (the reference standard). We also collected data on patient age, sex, weight, level of alanine aminotransferase on test day and peak values, concentration of acetaminophen, diagnoses (by site investigator and causality review committee), and outcome after 21 days. Differences between groups were analyzed using the Fisher exact test for categoric variables and the Kruskal-Wallis test or rank-sum test for continuous variables. RESULTS: AcetaSTAT discriminated between patients with and without acetaminophen-associated acute liver injury; the median AcetaSTAT test band amplitude for patients with acetaminophen-associated acute liver injury was 584 (range, 222-1027) vs 3678 (range, 394-8289) for those without (P < .001). AcetaSTAT identified patients with acetaminophen-associated acute liver injury with 100% sensitivity, 86.2% specificity, a positive predictive value of 89.2%, and a negative predictive value of 100%. Results from AcetaSTAT were positive in 4 subjects who received a causality review committee diagnosis of non-acetaminophen-associated acute liver injury; HPLC-EC and biochemical profiles were consistent with acetaminophen-associated acute liver injury in 3 of these cases. CONCLUSIONS: The competitive immunoassay AcetaSTAT shows a high degree of concordance with HPLC-EC results in identifying patients with acetaminophen-associated acute liver injury. This rapid and simple assay could increase early detection of this disorder and aid clinical management.

Child-Turcotte-Pugh Class is Best at Stratifying Risk in Variceal Hemorrhage: Analysis of a US Multicenter Prospective Study.

GOALS/BACKGROUND: Data on acute variceal hemorrhage (AVH) in the United States is limited and the best method to stratify risk is not clear. Taking advantage of a prospective US cohort study, we aimed to (1) describe clinical outcomes of AVH and their predictors; (2) compare predictors of 6-week mortality. STUDY: Prospective 15-center US cohort of patients with cirrhosis presenting with endoscopically proven AVH, all of whom received antibiotics, vapreotide (a somatostain analog) infusion and endoscopic band ligation. Patients were enrolled between August 2006 and April 2008. Primary outcome was 6-week mortality. Secondary outcome was 5-day treatment failure. The prognostic value of Child-Turcotte-Pugh (CTP) class, Model for End-stage Liver Disease (MELD) score and a recent recalibrated MELD were compared. RESULTS: Seventy eligible patient were enrolled; 18 (26%) patients died within 6-weeks of index bleed. Demographic, clinical, and laboratory data were compared between survivors and nonsurvivors. Multivariate models showed that admission CTP or the MELD score (separately) were independent predictors of survival. The discriminative values of CTP (area under receiver operating characteristic: 0.75) and MELD (area under receiver operating characteristic: 0.79) were good and not significantly different (P=0.27). However, calibration (correlation between observed and predicted mortality) test was significantly better for CTP than for MELD, with the recently described recalibrated MELD model having the worst agreement. Predicted mortality for CTP-A was <10%, CTP-B 10% to 30%; and CTP-C >33%. CONCLUSIONS: AVH mortality of 26% in the United States is in the upper range limit compared with recent series but may be due to inclusion of patients with more advanced cirrhosis. CTP score has the best overall performance in the prediction of 6-week mortality and is best at stratifying risk.

Regulation of nucleolin expression by miR-194, miR-206, and HuR.

Nucleolin is a proliferation-associated protein that is overexpressed in multiple types of cancer. The mechanisms leading to overexpression of nucleolin in specific cancers are not fully understood. This study found that nucleolin is notably elevated in breast cancer cell lines MCF-7 and MDA-231 compared to nonmalignant breast epithelial MCF-10A cells. In silico analyses revealed the presence of putative binding sites for microRNAs miR-194 and miR-206 in the 3'-untranslated region (3'-UTR) of Ncl mRNA. Transfection of the three cell lines with pre-miR-194 or pre-miR-206 specifically decreased the Ncl mRNA and protein expression. Treatments of the cells with antagomiR-194 or antagomiR-206 upregulated nucleolin expression ~2- to 3-fold. Co-transfection of cells with a reporter vector containing the Ncl 3'-UTR downstream from the Renilla luciferase gene and pre-miR-194 or pre-miR-206 led to a ~3-fold decrease in Renilla/firefly luciferase activity. Cytoplasmic levels of the RNA-binding protein HuR were higher in MCF-7 and MDA-231 cells than those in MCF-10A cells. RNA immunoprecipitation assays demonstrated that HuR binds to Ncl mRNA in all the three cell types. ShRNA-mediated knock-down of HuR induced a decrease in nucleolin expression, while exogenous expression of HuR led to upregulation of nucleolin expression. Analysis of the polysome-monosome distribution of Ncl mRNA in HuR knock-down cells demonstrated that HuR enhances the translation efficiency of Ncl mRNA. These findings demonstrate that nucleolin expression is down-regulated by miR-194 and miR-206 and upregulated by HuR.

Outcomes in Adults With Acute Liver Failure Between 1998 and 2013: An Observational Cohort Study.

BACKGROUND: Acute liver failure (ALF) is a rare syndrome of severe, rapid-onset hepatic dysfunction-without prior advanced liver disease-that is associated with high morbidity and mortality. Intensive care and liver transplantation provide support and rescue, respectively. OBJECTIVE: To determine whether changes in causes, disease severity, treatment, or 21-day outcomes have occurred in recent years among adult patients with ALF referred to U.S. tertiary care centers. DESIGN: Prospective observational cohort study. (ClinicalTrials .gov: NCT00518440). SETTING: 31 liver disease and transplant centers in the United States. PATIENTS: Consecutively enrolled patients-without prior advanced liver disease-with ALF (n = 2070). MEASUREMENTS: Clinical features, treatment, and 21-day outcomes were compared over time annually for trends and were also stratified into two 8-year periods (1998 to 2005 and 2006 to 2013). RESULTS: Overall clinical characteristics, disease severity, and distribution of causes remained similar throughout the study period. The 21-day survival rates increased between the two 8-year periods (overall, 67.1% vs. 75.3%; transplant-free survival [TFS], 45.1% vs. 56.2%; posttransplantation survival, 88.3% vs. 96.3% [P < 0.010 for each]). Reductions in red blood cell infusions (44.3% vs. 27.6%), plasma infusions (65.2% vs. 47.1%), mechanical ventilation (65.7% vs. 56.1%), and vasopressors (34.9% vs. 27.8%) were observed, as well as increased use of N-acetylcysteine (48.9% vs. 69.3% overall; 15.8% vs. 49.4% [P < 0.001] in patients with ALF not due to acetaminophen toxicity). When examined longitudinally, overall survival and TFS increased throughout the 16-year period. LIMITATIONS: The duration of enrollment, the number of patients enrolled, and possibly the approaches to care varied among participating sites. The results may not be generalizable beyond such specialized centers. CONCLUSION: Although characteristics and severity of ALF changed little over 16 years, overall survival and TFS improved significantly. The effects of specific changes in intensive care practice on survival warrant further study. PRIMARY FUNDING SOURCE: National Institutes of Health.