Clinical Features of COVID-19 Vaccine-Associated Autoimmune Hepatitis: A Systematic Review

Acute autoimmune hepatitis following COVID-19 mRNA vaccination: A population-based study using electronic health records in Singapore

Reports of coronavirus disease 2019 (COVID-19) vaccine-induced autoimmune hepatitis (AIH) have been largely limited to case reports and case series. To further investigate the association between COVID-19 mRNA vaccination and AIH, we conducted a nationwide study using observed-over-expected (O/E) and Self-Controlled Case Series (SCCS) analyses for acute presentations of AIH (AAIH) warranting admission. Patients were included if they had one or more of the following hepatitis-related signs and symptoms (fever, lethargy, jaundice or abdominal pain) reported up to 3 months prior to admission, deranged liver function tests [alanine transaminase (ALT) or aspartate aminotransferase (AST) greater than three times the upper limit of laboratory reference ranges], as well as biopsy results characteristic of AIH or response to steroid treatment for cases which did not undergo biopsy. Seventy-six patients fulfilled our case definition of AAIH within the study period from 1 January 2019 to 28 February 2023, with 6 patients having an estimated onset of AAIH within 42 days of COVID-19 mRNA vaccination. All 6 patients were females aged 40 years and above. In the O/E analysis, the rate ratios of AAIH among females aged 40 years and above in the primary cohort were 1.12 (95% confidence interval (CI) 0.14-9.40) and 1.06 (95% CI 0.24-4.74) in the 21 days and 42 days following vaccination respectively. In the SCCS analysis, we did not observe any statistically significant increase in incidence of AAIH in the 21 and 42 days following COVID-19 mRNA vaccination for both the primary and supplementary cohorts, as well as in the subgroup analysis involving females aged 40 years and above. Our findings suggest that COVID-19 mRNA vaccination does not appear to be associated with increased risk of AAIH requiring admissions in the population, although larger studies are required to confirm these findings.

Histopathological impact of SARS-CoV-2 on the liver: Cellular damage and long-term complications

Coronavirus disease 2019 (COVID-19), caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome, multiple organ failure, and death. Despite extensive studies on the pathogenicity of SARS-CoV-2, its impact on the hepatobiliary system remains unclear. While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels, the exact source of this damage is not fully understood. Proposed mechanisms for injury include direct cytotoxicity, collateral damage from inflammation, drug-induced liver injury, and ischemia/hypoxia. However, evidence often relies on blood tests with liver enzyme abnormalities. In this comprehensive review, we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients, drawing from liver biopsies, complete autopsies, and in vitro liver analyses. We present evidence of the direct impact of SARS-CoV-2 on the liver, substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes, including mitochondrial swelling, endoplasmic reticulum dilatation, and hepatocyte apoptosis. Additionally, we describe the diverse liver pathology observed during COVID-19 infection, encompassing necrosis, steatosis, cholestasis, and lobular inflammation. We also discuss the emergence of long-term complications, notably COVID-19-related secondary sclerosing cholangitis. Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.

Immunogenicity and risk factors for poor humoral immune response to SARS-CoV-2 vaccine in patients with autoimmune hepatitis: a systematic review and meta-analysis

BACKGROUND

Research on the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with autoimmune hepatitis (AIH) has produced varied results, and the determinants of the immunological response remain largely elusive.

METHODS

A comprehensive search of three primary databases (PubMed, Embase, and Web of Science) yielded pertinent studies on the topic. The data extraction was a collaborative effort among three independent researchers, who subsequently reconvened to validate the key data that were collated. The primary outcomes were the magnitudes of humoral and cellular immune responses to the vaccines. The secondary outcomes were related to factors affecting the humoral immune response post-vaccination.

RESULT

Our systematic review incorporated eight studies, and the meta-analysis involved three. The average antibody response rates after one, two, and three doses of the SARS-CoV-2 vaccine were 86%, 82%, and 91%, respectively. Unexpectedly, the antibody concentrations of seropositive patients were markedly lower than those of their healthy counterparts. The cellular immune response rates after two and three vaccine doses were 74% and 56%, respectively. Treatment with mycophenolate mofetil and corticosteroids was associated with a notable decrease in seropositivity [pooled odds ratio (95% confidence interval): 2.62 (2.12-3.25) and 2.4 (1.51-3.82), respectively]. In contrast, azathioprine had no discernable impact on the humoral response.

CONCLUSION

In patients with AIH, the immune response to COVID-19 vaccination is attenuated. Specific immunosuppressive agents, such as steroids and MMF, have been found to reduce antibody responses. Recognizing these determinants is foundational to formulating individualized vaccination strategies for patients with AIH. Further research with an emphasis on post-vaccination cellular immunity will be essential to refine the vaccination approaches for this demographic.

COVID-19 and the Liver: A Complex and Evolving Picture

Although the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily attacks the respiratory system, other organs, such as the liver, are also affected. In this overview, the effects of SARS-CoV-2 infection on the liver in both healthy people and in those with pre-existing liver disease are documented; the relationship between coronavirus disease 19 (COVID-19) vaccination and liver injury is examined; the mechanism of SARS-CoV-2-associated liver injury is explored; and the long-term consequences of COVID-19 are delineated, both in people with and without pre-existing liver disease.