Racial and ethnic differences in presentation, etiology, and outcomes of acute liver failure in the United States

The impact of race and gender on the outcomes of patients with acetaminophen-induced acute liver failure: propensity score-matched analysis of the NIS database

BACKGROUND

Acetaminophen overdose is one of the leading causes of acute liver failure in the USA. In this study, we investigated the impact of race and gender on the hospital outcomes of patients admitted with acetaminophen-induced acute liver failure.

METHODS

From the National Inpatient Sample between the years 2016 and 2019, patients with acetaminophen-induced acute liver failure were selected and stratified based on gender (Male and Female) and race (White, Black and Hispanic). The cases were propensity score-matched to controls (male and Whites) and were compared along the following endpoints: mortality, length of stay, hospitalization costs, and hepatic complications.

RESULTS

Among patients with acetaminophen-induced acute liver failure, females experienced higher rates of mortality (16.60% vs. 11.70%, P = 0.004) and clinical illness, including hypotension (11.80% vs. 7.15%, P = 0.002) and ventilator use (40.80% vs. 30.00%, P < 0.001). When stratified by race, Black patients had longer hospital stays (Black vs. White, 8.76 days vs. 7.46 days, P = 0.03). There were no significant differences in outcomes between Hispanic and White patients. No significant differences in mortality were shown between races.

CONCLUSION

We found that females had a higher rate of mortality and incidence of hepatic encephalopathy compared to males. When stratified by race, Blacks were shown to have longer hospital stay. Females and racial minorities were also affected by special healthcare needs after discharge compared to their male and White cohorts, respectively.

Pharmacokinetics of Ceftazidime-Avibactam in Combination with Aztreonam (COMBINE) in a Phase 1, Open-Label Study of Healthy Adults

Scant pharmacokinetic (PK) data are available on ceftazidime-avibactam (CZA) and aztreonam (ATM) in combination, and it is unknown if CZA-ATM exacerbates alanine aminotransferase (ALT)/aspartate aminotransferase (AST) elevations relative to ATM alone. This phase 1 study sought to describe the PK of CZA-ATM and assess the associations between ATM exposures and ALT/AST elevations. Subjects (n = 48) were assigned to one of six cohorts (intermittent infusion [II] CZA, continuous infusion [CI] CZA, II ATM, CI ATM [8 g/daily], II CZA with II ATM [6 g/daily], and II CZA with II ATM [8 g/daily]), and study product(s) were administered for 7 days. A total of 19 subjects (40%) had ALT/AST elevations, and most (89%) occurred in the ATM/CZA-ATM cohorts. Two subjects in the CI ATM cohort experienced severe ALT/AST elevations, which halted the study. All subjects with ALT/AST elevations were asymptomatic with no other signs of liver injury, and all ALT/AST elevations resolved without sequalae after cessation of dosing. In the population PK (PopPK) analyses, CZA-ATM administration reduced total ATM clearance by 16%, had a negligible effect on total ceftazidime clearance, and was not a covariate in the avibactam PopPK model. In the exposure-response analyses, coadministration of CZA-ATM was not found to augment ALT/AST elevations. Modest associations were observed between ATM exposure (maximum concentration of drug in serum [Cmax] and area under the concentration-time curve [AUC]) and ALT/AST elevations in the analysis of subjects in the II ATM/CZA-ATM cohorts. The findings suggest that administration of CZA-ATM reduces ATM clearance but does not exacerbate AST/ALT elevations relative to ATM alone. The results also indicate that CI ATM should be used with caution.

Safety of Ceftazidime-Avibactam in Combination with Aztreonam (COMBINE) in a Phase I, Open-Label Study in Healthy Adult Volunteers

This phase I study evaluated the safety of the optimal ceftazidime-avibactam (CZA) with aztreonam (ATM) regimens identified in hollow fiber infection models of MBL-producing Enterobacterales. Eligible healthy subjects aged 18 to 45 years were assigned to one of six cohorts: 2.5 g CZA over 2 h every 8 h (approved dose), CZA continuous infusion (CI) (7.5 g daily), 2 g ATM over 2 h every 6 h, ATM CI (8 g daily), CZA (approved dose) with 1.5 g ATM over 2 h every 6 h, and CZA (approved dose) with 2 g ATM over 2 h every 6 h. Study drug(s) were administered for 7 days. The most frequently observed adverse events (AEs) were hepatic aminotransferase (ALT/AST) elevations (n = 19 subjects). Seventeen of the 19 subjects with ALT/AST elevations received ATM alone or CZA-ATM. The incidence of ALT/AST elevations was comparable between the ATM-alone and CZA-ATM cohorts. Two subjects in the ATM CI cohort experienced severe ALT/AST elevation AEs. All subjects with ALT/AST elevations were asymptomatic with no other findings suggestive of liver injury. Most other AEs were of mild to moderate severity and were similar across cohorts, except for prolonged prothrombin time (more frequent in CZA-ATM cohorts). These results suggest that CZA-ATM administered as 2-h intermittent infusions is safe and that some caution should be exercised with the use of ATM CI at an ATM dose of 8 g daily. If CZA-ATM is prescribed, clinicians are advised to monitor liver function, hematologic, and coagulation parameters. Future controlled studies are required to better define the safety and efficacy of the CZA-ATM regimens evaluated in this phase I study.

Liver Transplantation for Acute Liver Injury in Asians Is More Likely Due to Herbal and Dietary Supplements

Drug-induced liver injury (DILI) due to medications and herbal and dietary supplements (HDSs) is a major cause of acute liver injury leading to liver transplantation (LT). This study used United Network for Organ Sharing LT data to analyze severe HDS-induced acute liver injury in the United States. By convention, patients with acute DILI are listed as "Acute Hepatic Necrosis" (AHN) under the subheading "AHN: Drug Other Specify." All patients waitlisted from 1994 to 2020 were divided into 3 subgroups: "HDS DILI," "Non-HDS DILI," and "AHN: unknown drug." Analyses were performed to identify epidemiologic differences between patients with HDS DILI and non-HDS DILI. A subanalysis was performed for transplanted patients, including longitudinal changes. Of 1875 patients waitlisted for LT, 736 (39.2%) underwent LT. The proportion of Asian patients in the HDS DILI group was significantly higher compared with that in the non-HDS DILI group (17.4% versus 3.8%; P < 0.001). Excluding acetaminophen cases, the proportion of Black patients in the HDS DILI versus non-HDS group was significantly lower (8.7% versus 25.3%; P < 0.001). Waitlisted patients with HDS DILI were significantly older (median age, 38 years for HDS DILI versus 31 years for non-HDS DILI; P = 0.03). Lastly, the number of patients requiring LT due to HDS DILI increased significantly over time with more than 70% of cases occurring in the last 10 years (2010-2020) compared with the prior 15 years (1994-2009; Ptrend  = 0.001). Ethnicity may help in identifying the cause of severe acute DILI, a growing problem as more patients experiment with HDS.

Gender and race/ethnicity differences in living kidney donor demographics: Preference or disparity?

In the United States, women are over-represented and Blacks are under-represented as living kidney donors. A traditional bioethics approach would state that as long as living donors believe that the benefits of participation outweigh the risks and harms (beneficence) and they give a voluntary and informed consent, then the demographics reflect a mere difference in preferences. Such an analysis, however, ignores the social, economic and cultural determinants as well as various forms of structural discrimination (e.g., racism, sexism) that may imply that the distribution is less voluntary than may appear initially. The distribution also raises justice concerns regarding the fair recruitment and selection of living donors. We examine the differences in living kidney donor demographics using a vulnerabilities analysis and argue that these gender and racial differences may not reflect mere preferences, but rather, serious justice concerns that need to be addressed at both the individual and systems level.

Transplant center experience influences spontaneous survival and waitlist mortality in acute liver failure: An analysis of the UNOS database

Transplant centers coordinate complex care in acute liver failure (ALF), for which liver transplant (LT) can be lifesaving. We studied associations between waitlist outcomes and center (1) ALF waitlist volume (low: <20; medium: 20-39; high: 40+ listings) and (2) total LT volume (<600, 600-1199, 1200+ LTs) in a retrospective cohort of 3248 adults with ALF listed for LT at 92 centers nationally from 2002 to 2019. Predicted outcome probabilities (LT, died/too sick, spontaneous survival [SS]) were obtained with multinomial regression, and observed-to-expected ratios were calculated. Median center outcome rates were 72.6% LT, 18.2% died/too sick, and 6.1% SS. SS was significantly higher with greater center ALF volume (median 0% for low-, 5.9% for medium-, and 8.6% for high-volume centers; P = .039), while waitlist mortality was highest at low-volume centers (median 21.4%, IQR: 16.1%-26.7%; P = .042). Significant heterogeneity in center performance was observed for waitlist mortality (observed-to-expected ratio range: 0-4.1) and particularly for SS (0-6.4), which persisted despite accounting for recipient case mix. This novel study demonstrates that increased center experience is associated with greater SS and reduced waitlist mortality for ALF. More-focused management pathways are needed to improve ALF outcomes at less-experienced centers and to identify opportunities for improvement at large.

Black Adult Patients With Acute Liver Failure Are Sicker and More Likely to Undergo Liver Transplantation Than White Patients

Racial and ethnic differences in the presentation and outcomes of patients wait-listed with acute liver failure (ALF) have not been explored. Adult patients with ALF wait-listed for liver transplantation (LT) from 2002 to 2016 were investigated using the United Network for Organ Sharing database. Clinical characteristics and causative etiologies were compared between white, black, Hispanic, and Asian patients with ALF who were wait-listed as status 1. A competing risk analysis was used to explore differences in LT and wait-list removal rates. Kaplan-Meier survival curves were used to explore differences in 1-year posttransplant survival. There were 8208 patients wait-listed with a primary diagnosis of ALF; 4501 were wait-listed as status 1 (55.3% of whites, 64.4% of blacks, 51.6% of Hispanics, 40.7% of Asians; P < 0.001). Black patients had higher bilirubin and Model for End-Stage Liver Disease at wait-listing than other groups. White patients were the most likely to have acetaminophen toxicity as a causative etiology, whereas black patients were the most likely to have autoimmune liver disease. Black patients were significantly more likely to undergo LT than white patients (hazard ratio, 1.20; 95% confidence interval, 1.08-1.30). There was no difference in wait-list removal because of death or clinical deterioration among racial/ethnic groups. The 1-year posttransplant survival was lowest in black patients (79.6%) versus white (82.8%), Hispanic (83.9%), and Asian (89.3%) patients (P = 0.02). In conclusion, etiologies of ALF vary by race and ethnicity. Black patients with ALF were more likely to be wait-listed as status 1 and undergo LT than white patients, but they were sicker at presentation. The 1-year posttransplant survival rate was lowest among black patients.

Racial disparities in the treatment of acute overdose in the emergency department

OBJECTIVES

Racial and ethnic disparities in the United States continue to exist in many disciplines of medicine, extending to care in the Emergency Department (ED). We sought to examine the relationship between patient race/ethnicity and use of either antidotal therapy or gastrointestinal decontamination for individuals presenting to the ED for acute drug overdose.

METHODS

We completed a secondary analysis of a prospective cohort of patients with suspected acute overdose presenting to two urban tertiary care hospitals between 2009 and 2014. Race was self-identified during ED registration. Antidote administration (primary outcome) and gastrointestinal decontamination (secondary outcome) were reviewed and verified via agreement between two board certified medical toxicologists. Associations between race and outcomes were analyzed using a logistic regression model.

RESULTS

We reviewed 3252 ED patients with acute overdose. Overall, 542 people were treated with an antidote and 234 cases were treated with activated charcoal, either single or multiple dose. Compared to Whites, Blacks and Hispanics were significantly less likely to receive any antidote. The analysis was underpowered to detect racial disparities in the administration of activated charcoal.

CONCLUSIONS

Blacks and Hispanics are significantly less likely to receive any antidote when presenting to the ED for acute drug overdose. Further studies are needed to determine national prevalence of this apparent disparity in care and to fully characterize how race plays a role in management of acute overdose.

Classification and Epidemiologic Aspects of Acute Liver Failure

Acute liver failure is a rare condition with high short-term morbidity and mortality. The most widely accepted definition is an abnormality in coagulation with any degree of encephalopathy in a patient without cirrhosis and an illness duration of less than 26 weeks. Multiple classifications systems are currently in use to help categorize the condition. This article reviews the most commonly used systems. The epidemiologic aspects of the disease are also reviewed, including incidence, prevalence, demographics, geographic distribution, and racial and cultural factors and are discussed for the various subtypes of acute liver failure.

Nonacetaminophen Drug-Induced Acute Liver Failure

Acute liver failure of all causes is diagnosed in between 2000 and 2500 patients annually in the United States. Drug-induced acute liver failure is the leading cause of acute liver failure, accounting for more than 50% of cases. Nonacetaminophen drug injury represents 11% of all cases in the latest registry from the US Acute Liver Failure Study Group. Although rare, acute liver failure is clinically dramatic when it occurs, and requires a multidisciplinary approach to management. In contrast with acetaminophen-induced acute liver failure, non-acetaminophen-induced acute liver failure has a more ominous prognosis with a lower liver transplant-free survival.

Idiosyncratic Drug Induced Liver Injury in African-Americans Is Associated With Greater Morbidity and Mortality Compared to Caucasians

OBJECTIVES

Idiosyncratic drug induced liver injury (DILI) is a rare but potentially serious liver disorder and a major cause of significant liver injury. Limited data exist on racial differences in DILI incidence, presentation, and course.

METHODS

We compared the causative agents, clinical features, and outcomes of DILI among self-described African-Americans and non-Hispanic whites (Caucasians) enrolled in the DILIN Prospective Study. Individuals with definite, highly likely, or probable DILI enrolled between September 2004 and February 2016 were included in this analysis.

RESULTS

144 African-Americans and 841 Caucasian patients met the eligibility criteria. Causal medications varied by race: trimethoprim/sulfamethoxazole being the most common cause among African-Americans (7.6 vs. 3.6%) followed by methyldopa (4 vs. <1%), phenytoin (5 vs. <1%), isoniazid (4 vs. 4%), and amoxicillin/clavulanate (4.1 vs. 13.4%). The severity of illness, however, tended to be greater in African-Americans than Caucasians as determined by peak mean bilirubin (14.3 vs. 12.8 mg/dl), INR (1.9 vs. 1.6), and DILIN severity score (3.0 vs. 2.6). The frequency of severe cutaneous reactions was significantly higher in African-Americans (2.1 vs. 0.36% in Caucasians, P=0.048). African-Americans also had higher rates of hospitalization (76.7 vs. 57.6%, P<0.001), liver transplantation or liver related death by 6 months (10.2 vs. 5.8%, P=0.02 after controlling for selected covariates), and chronic DILI (24 vs. 16%, P=0.06).

CONCLUSIONS

The most common DILI causative agents differ between African-Americans and Caucasians. African-Americans are more likely to have severe cutaneous reactions and more severe liver injury leading to worse outcomes, including death and liver transplant.

Two-year outcomes in initial survivors with acute liver failure: results from a prospective, multicentre study

BACKGROUND & AIMS

The long-term clinical outcomes in initial survivors with acute liver failure (ALF) are not well known. The aim of this study was to provide an overview of the 2-year clinical outcomes among initial survivors and liver transplant (LT) recipients that were alive 3 weeks after enrolment in the Acute Liver Failure Study Group (ALFSG).

METHODS

Outcomes in adult ALFSG patients that were enrolled between 1998 and 2010 were reviewed.

RESULTS

Two-year patient survival was significantly higher in the 262 LT recipients (92.4%) compared to the 306 acetaminophen (APAP) spontaneous survivors (SS) (89.5%) and 200 non-APAP SS (75.5%) (P < 0.0001). The causes of death were similar in the three groups but the time to death was significantly longer in the LT recipients (P < 0.0001). Independent predictors of 2-year mortality in the APAP group were a high serum phosphate level and patient age (c-statistic = 0.65 (0.54, 0.76)), patient age and days from jaundice to ALF onset in the non-APAP group (c-statistic = 0.69 (0.60, 0.78)), and patient age, days from jaundice, and higher coma grade in the LT recipients (c-statistic = 0.74 (0.61, 0.87)). The LT recipients were significantly more likely to be employed and have a higher educational level (P < 0.05).

CONCLUSIONS

Two-year outcomes in initial survivors of ALF are generally good but non-APAP patients have a significantly lower survival which may relate to pre-existing medical comorbidities. Spontaneous survivors with APAP overdose experience substantial morbidity during follow-up from ongoing psychiatric and substance abuse issues.

Autoimmune hepatitis in diverse ethnic populations and geographical regions

Autoimmune hepatitis has diverse clinical phenotypes and outcomes in ethnic groups within a country and between countries, and these differences may reflect genetic predispositions, indigenous etiological agents, pharmacogenomic mechanisms and socioeconomic reasons. In the USA, African-American patients have cirrhosis more commonly, treatment failure more frequently and higher mortality than white American patients. Survival is poorest in Asian-American patients. Autoimmune hepatitis in other countries is frequently associated with genetic predispositions that may favor susceptibility to indigenous etiological agents. Cholestatic features influence treatment response; acute-on-chronic liver disease increases mortality and socioeconomic and cultural factors affect prognosis. Ethnic-based deviations from classical phenotypes and the frequency of late-stage disease can complicate the diagnosis and management of autoimmune hepatitis in non-white populations.

Is Race Determination in the Medicolegal Setting Important?

Racial designations have evolved over the years to accommodate the changes in our population demographics. The Federal Office of Management and Budget (OMB) has developed Federal Standards to assist with the uniform documentation and reporting of race and ethnicity. A minimum of five defined categories currently exist for race (American Indian or Alaska Native, Asian, Black or African American, Native Hawaiian or Other Pacific Islander and White). Ethnicity is separated into either Hispanic origin or Non-Hispanic origin. Current death certificates allow for the selection of one or more races; however, only one ethnicity may be chosen. Race of unknown decedents is either based subjectively on the observer's opinion or, in severely decomposed or skeletal remains, by anthropological analysis utilizing sound statistical methodology. If the data and statistical analysis suggest a good classification, the race determination will be correct more often than not. Information obtained from the National Missing and Unidentified Persons System (NamUs) indicates that absence of race determination does not hinder the identification potential. Mortality rates, life expectancy, disease risk and causes of death are often disaggregated by race and/or ethnicity. Differences in the presentation, etiology and outcomes of many diseases have been based on race and ethnicity data. Uniform collection of this data is the key to its importance. Medical examiners, coroners and others tasked with examination of decedents should utilize the defined categories set forth in the OMB Revised Standards for race and ethnicity documentation.

Short and long-term outcomes in patients with acute liver failure due to ischemic hepatitis

AIMS

The purpose of this study is to describe the incidence and presenting features of patients with acute liver failure (ALF) due to ischemic hepatitis and the prognostic factors associated with short (three-week) and long-term outcomes.

METHODS

Retrospective cohort analysis of adult patients enrolled in the Acute Liver Failure Study Group between 1998 and 2008 with ALF due to ischemic hepatitis. Predictors of adverse outcomes three weeks after presentation were identified by univariate and multivariate analysis.

RESULTS

Ischemic hepatitis accounted for 51 (4.4%) of the 1147 ALF patients enrolled. Mean age was 50 years, 63% were female, and only 31% had known heart disease before presentation. However, a cardiopulmonary precipitant of hepatic ischemia was identified in 69%. Three-week spontaneous survival was 71%, two patients (4%) underwent liver transplantation, and the remaining 13 patients (25%) died of multi-organ failure. Adverse outcomes were more frequent in subjects with higher admission phosphate levels (HR 1.3, 95% CI 1.1-1.6, P = 0.008) and in subjects with grade 3/4 encephalopathy at presentation (HR: 8.4, 95% CI 1.1-66.5, P = 0.04). Nineteen of the 28 short-term survivors (68%) were still alive at a median follow-up of 3.7 years whereas nine (32%) others had died at a median follow-up of 2 months.

CONCLUSIONS

A higher admission serum phosphate level and more advanced encephalopathy are associated with a lower likelihood of short-term survival of hospitalized patients with ALF due to ischemic hepatitis. Long-term outcomes are largely determined by underlying cardiovascular morbidity and mortality.

Liver transplant outcomes in a Canadian First Nations population

BACKGROUND

A higher incidence of autoimmune disorders may predispose First Nations (FN) individuals to higher rates and more severe episodes of rejection, graft loss and mortality following liver transplantation for advanced liver disease.

METHODS

A retrospective review of patient outcomes in a single centre providing long-term follow-up care for FN and non-FN patients transplanted for advanced liver disease was conducted.

RESULTS

A total of 20 FN and 129 non-FN charts were available for review. FN subjects were younger at transplantation (mean [± SD] age 32.4±4.1 years versus 46.3±1.4 years; P=0.00005), less often male (35% versus 58%; P=0.05), more commonly transplanted for autoimmune hepatitis (30% versus 4.7%; P=0.006), less often from urban residences (25% versus 74%; P=0.0001) and less compliant with medical care (20% versus 80%; P=0.007). After a mean follow-up period of 11.0±1.5 years and 8.4±0.5 years in FN and non-FN subjects, respectively, the incidence and severity of rejection, graft and patient survival were similar between cohorts.

CONCLUSION

Although demographic profiles, nature of the underlying disease and compliance differed, the rates and severity of rejection, graft and patient survival were similar in FN and non-FN patients who underwent liver transplantation for advanced liver disease.

Acute liver failure

PURPOSE OF REVIEW

Clinical investigations in acute liver failure (ALF) continue to advance our understanding and capacity to diagnose and treat afflicted children and adults. The purpose of this review is to summarize the advances in clinical research in ALF during 2009-2010 that are pertinent to hepatologists and transplant surgeons caring for these critically ill patients.

RECENT FINDINGS

Principal advances occurred in the characterization of cause and epidemiology, genetic susceptibility, assessment of prognosis for survival with medical therapy, clarification of long-term outcomes of transplantation for ALF, and publication of the final results of large randomized, placebo-controlled therapeutic trials.

SUMMARY

Despite advances in our understanding, ALF remains a cause of significant mortality in children and adults because of the absence of curative medical therapy. Hence, only emergency liver transplantation is reliably life-saving. There is an urgent need for better understanding of the pathogenesis of ALF caused by different causes, of genetic susceptibility, development of validated prognostic indicators and application of this knowledge to devise new therapeutic strategies for testing in appropriately powered, randomized controlled trials.