Addressing sex-based disparities in liver transplantation.

PURPOSE OF REVIEW: Disparities in access to liver transplantation by sex have been well described, disadvantaging women. Understanding the multifactorial causes of these disparities as well as the variety of proposed solutions is critical to improving access to this life-saving intervention for women. This review aims to summarize the current body of evidence on observed sex disparities in liver transplantation and highlight actionable, evidence-based mechanisms by which these disparities can be addressed. RECENT FINDINGS: Strategies for addressing sex disparities in liver transplantation include increasing organ utilization, changing allocation policy, and leveraging public policies to reduce the incidence of end-stage liver disease. Several other promising interventions are currently being explored. SUMMARY: In the United States, women face additional barriers to liver transplantation on the basis of sex. Immediate action is necessary to systematically address these inequities.

Correlation Between Clinical and Pathological Findings of Liver Injury in 27 Patients With Lethal COVID-19 Infections in Brazil.

Liver test abnormalities are frequently observed in patients with coronavirus disease 2019 (COVID-19) and are associated with worse prognosis. However, information is limited about pathological changes in the liver in this infection, so the mechanism of liver injury is unclear. Here we describe liver histopathology and clinical correlates of 27 patients who died of COVID-19 in Manaus, Brazil. There was a high prevalence of liver injury (elevated alanine aminotransferase and aspartate aminotransferase in 44% and 48% of patients, respectively) in these patients. Histological analysis showed sinusoidal congestion and ischemic necrosis in more than 85% of the cases, but these appeared to be secondary to systemic rather than intrahepatic thrombotic events, as only 14% and 22% of samples were positive for CD61 (marker of platelet activation) and C4d (activated complement factor), respectively. Furthermore, the extent of these vascular findings did not correlate with the extent of transaminase elevations. Steatosis was present in 63% of patients, and portal inflammation was present in 52%. In most cases, hepatocytes expressed angiotensin-converting enzyme 2 (ACE2), which is responsible for binding and entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), even though this ectoenzyme was minimally expressed on hepatocytes in normal controls. However, SARS-CoV-2 staining was not observed. Most hepatocytes also expressed inositol 1,4,5-triphosphate receptor 3 (ITPR3), a calcium channel that becomes expressed in acute liver injury. Conclusion: The hepatocellular injury that commonly occurs in patients with severe COVID-19 is not due to the vascular events that contribute to pulmonary or cardiac damage. However, new expression of ACE2 and ITPR3 with concomitant inflammation and steatosis suggests that liver injury may result from inflammation, metabolic abnormalities, and perhaps direct viral injury.

Neutrophils interact with cholangiocytes to cause cholestatic changes in alcoholic hepatitis.

BACKGROUND & OBJECTIVES: Alcoholic hepatitis (AH) is a common but life-threatening disease with limited treatment options. It is thought to result from hepatocellular damage, but the presence of cholestasis worsens prognosis, so we examined whether bile ducts participate in the pathogenesis of this disease. DESIGN: Cholangiocytes derived from human bile ducts were co-cultured with neutrophils from patients with AH or controls. Loss of type 3 inositol 1,4,5-trisphosphate receptor (ITPR3), an apical intracellular calcium channel necessary for cholangiocyte secretion, was used to reflect cholestatic changes. Neutrophils in contact with bile ducts were quantified in liver biopsies from patients with AH and controls and correlated with clinical and pathological findings. RESULTS: Liver biopsies from patients with AH revealed neutrophils in contact with bile ducts, which correlated with biochemical and histological parameters of cholestasis. Cholangiocytes co-cultured with neutrophils lost ITPR3, and neutrophils from patients with AH were more potent than control neutrophils. Biochemical and histological findings were recapitulated in an AH animal model. Loss of ITPR3 was attenuated by neutrophils in which surface membrane proteins were removed. RNA-seq analysis implicated integrin ß1 (ITGB1) in neutrophil-cholangiocyte interactions and interference with ITGB1 on cholangiocytes blocked the ability of neutrophils to reduce cholangiocyte ITPR3 expression. Cell adhesion molecules on neutrophils interacted with ITGB1 to trigger RAC1-induced JNK activation, causing a c-Jun-mediated decrease in ITPR3 in cholangiocytes. CONCLUSIONS: Neutrophils bind to ITGB1 on cholangiocytes to contribute to cholestasis in AH. This previously unrecognised role for cholangiocytes in this disease alters our understanding of its pathogenesis and identifies new therapeutic targets.

Abnormal Liver Tests in COVID-19: A Retrospective Observational Cohort Study of 1,827 Patients in a Major U.S. Hospital Network.

BACKGROUND AND AIMS: The coronavirus-19 disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 virus, is associated with significant morbidity and mortality attributable to pneumonia, acute respiratory distress syndrome, and multiorgan failure. Liver injury has been reported as a nonpulmonary manifestation of COVID-19, but characterization of liver test abnormalities and their association with clinical outcomes is incomplete. APPROACH AND RESULTS: We conducted a retrospective cohort study of 1,827 patients with confirmed COVID-19 who were hospitalized within the Yale-New Haven Health System between March 14, 2020 and April 23, 2020. Clinical characteristics, liver tests (aspartate aminotransferase [AST], alanine aminotransferase [ALT], alkaline phosphatase [ALP], total bilirubin [TBIL], and albumin) at three time points (preinfection baseline, admission, and peak hospitalization), and hospitalization outcomes (severe COVID-19, intensive care unit [ICU] admission, mechanical ventilation, and death) were analyzed. Abnormal liver tests were commonly observed in hospitalized patients with COVID-19, both at admission (AST 66.9%, ALT 41.6%, ALP 13.5%, and TBIL 4.3%) and peak hospitalization (AST 83.4%, ALT 61.6%, ALP 22.7%, and TBIL 16.1%). Most patients with abnormal liver tests at admission had minimal elevations 1-2× the upper limit of normal (ULN; AST 63.7%, ALT 63.5%, ALP 80.0%, and TBIL 75.7%). A significant proportion of these patients had abnormal liver tests prehospitalization (AST 25.9%, ALT 38.0%, ALP 56.8%, and TBIL 44.4%). Multivariate analysis revealed an association between abnormal liver tests and severe COVID-19, including ICU admission, mechanical ventilation, and death; associations with age, male sex, body mass index, and diabetes mellitus were also observed. Medications used in COVID-19 treatment (lopinavir/ritonavir, hydroxychloroquine, remdesivir, and tocilizumab) were associated with peak hospitalization liver transaminase elevations >5× ULN. CONCLUSIONS: Abnormal liver tests occur in most hospitalized patients with COVID-19 and may be associated with poorer clinical outcomes.