Abstract
BACKGROUND: Suggested mechanisms for SARS-CoV-2 direct liver infection have been proposed by others to involve both cholangiocytes and hepatocytes. Early clinical studies have highlighted abnormal liver biochemistry with COVID-19 infection as often not being severe, with elevated liver enzymes <5X the upper limit of normal. METHODS: Liver enzymes were evaluated and compared in patients admitted with a diagnosis of COVID-19 in a deidentified Internal Medicine-Medical Teaching Unit/hospitalist admission laboratory database. Comparisons in the incidence of severe liver injury (alanine aminotransferase >10 times upper limit of normal) were made for patients with pre-Omicron SARS-CoV-2 (November 30, 2019, to December 15, 2021) and Omicron SARS-CoV-2 (December 15, 2021, to April 15, 2022). Comprehensive hospital health records were also reviewed for the 2 patient cases discussed. One patient had a liver biopsy that was evaluated with H&E and immunohistochemistry staining using an antibody against COVID-19 spike protein. RESULTS: The evaluation of a deidentified admissions laboratory database found the incidence of severe liver injury was 0.42% with Omicron versus 0.30% with pre-Omicron variants of COVID-19. In both patient cases discussed, abnormal liver biochemistry and a negative comprehensive workup strongly suggest COVID-19 as the cause of severe liver injury. In the one patient with liver biopsy, immunohistochemistry staining suggests SARS-CoV-2 presence in the portal and lobular spaces in association with immune cell infiltration. CONCLUSIONS: The Omicron variant of SARS-CoV-2 should be considered in the differential diagnosis of severe acute liver injury. Our observation suggests that this new variant, either through direct liver infection and/or mediating immune dysfunction, can result in severe liver injury.