Association of Acetaminophen (Paracetamol) Use With Severity and Outcomes in Patients With Viral Hepatitis-Associated Acute Liver Failure.

INTRODUCTION: Acute viral hepatitis (AVH) comprises 11% of acute liver failure (ALF) in North America while acetaminophen (APAP) toxicity represents 46%. The use of APAP to treat prodromal hepatitis symptoms is common. It is unknown if concurrent APAP use impacts liver injury in AVH-induced ALF. METHODS: In this prospective, multicenter cohort study, 356 patients meeting criteria for AVH including hepatitis A, B, Epstein-Barr virus, and herpes simplex virus, all leading to ALF (hepatic encephalopathy after acute illness, international normalized ratio ≥1.5), or acute liver injury (acute liver injury, international normalized ratio >2.0, no hepatic encephalopathy) were reviewed for evidence of APAP use: APAP ingestion history or measurement of serum APAP level or APAP-CYS adducts, a specific biomarker released into blood with APAP injury. Patients were grouped by APAP exposure level, from high (measurable APAP levels or toxic APAP-CYS), medium (therapeutic APAP-CYS), low (history of APAP ingestion only and/or barely detectable APAP-CYS), or no exposure recorded. RESULTS: Two hundred five of 356 patients (57.5%) with AVH-ALF had evidence of APAP use: 87 out of 356 (24%) demonstrated high or medium exposures. The aminotransferase and bilirubin levels of high/medium group resembled a mixed APAP-viral injury. Mortality was the highest (51.6%, 21.4%, 28.8%, and 30.5%), and transplant-free survival was the lowest (22.6%, 44.6%, 41.5%, and 40.4%) in the high exposure group compared with medium, low, and no exposure groups. However, the specific comparisons of mortality and transplant-free survival between the high exposure and no exposure groups were not statistically different even after adjusting for baseline patient characteristics differences. DISCUSSION: APAP use in AVH-ALF is common and may negatively impact outcomes compared with little or no APAP exposure. Prospective studies of the safest and effective dose of APAP to use in patients with AVH are needed.

Spatiotemporal immune atlas of a clinical-grade gene-edited pig-to-human kidney xenotransplant.

Pig-to-human xenotransplantation is rapidly approaching the clinical arena; however, it is unclear which immunomodulatory regimens will effectively control human immune responses to pig xenografts. Here, we transplant a gene-edited pig kidney into a brain-dead human recipient on pharmacologic immunosuppression and study the human immune response to the xenograft using spatial transcriptomics and single-cell RNA sequencing. Human immune cells are uncommon in the porcine kidney cortex early after xenotransplantation and consist of primarily myeloid cells. Both the porcine resident macrophages and human infiltrating macrophages express genes consistent with an alternatively activated, anti-inflammatory phenotype. No significant infiltration of human B or T cells into the porcine kidney xenograft is detectable. Altogether, these findings provide proof of concept that conventional pharmacologic immunosuppression may be able to restrict infiltration of human immune cells into the xenograft early after compatible pig-to-human kidney xenotransplantation.