Immune-mediated liver injury represented as overlap syndrome after SARS-CoV-2 vaccination

Autoimmune hepatitis under the COVID-19 veil: an analysis of the nature of potential associations

In recent years, the novel coronavirus infectious disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has led to over 670 million infections and nearly 7 million deaths worldwide. The global pandemic of COVID-19 has precipitated a significant public health crisis. The prevalence of liver function abnormalities associated with SARS-CoV-2 is as high as 53% among healthy individuals or patients with autoimmune hepatitis (AIH) and shows a positive correlation with disease severity; moreover, specific adaptive immune responses can influence the trajectory and outcomes of COVID-19. For instance, SARS-CoV-2 may impact autoimmunity through mechanisms such as excessive stimulation of immune responses and molecular mimicry, particularly in genetically predisposed individuals. Currently, the overall mutational trend of SARS-CoV-2 indicates heightened infectivity and immune evasion capabilities. Consequently, vaccination remains crucial for universal protection against this disease. Nevertheless, alongside the widespread implementation of vaccination programs globally, an increasing number of cases have been documented where COVID-19 vaccination appears to trigger new-onset autoimmune hepatitis; yet definitive evidence is still pending elucidation regarding causality. In this review, we analyse the clinical-immunological characteristics, risks associated with severe disease progression, and prognosis for AIH patients infected with SARS-CoV-2; discuss the detrimental effects exerted by SARS-CoV-2 on hepatic function; summarise the mechanisms and attributes leading to new-onset AIH; as well as provide insights into how vaccination may interfere with autoimmunity processes. We continue to underscore the significance of vaccination while aiming to enhance awareness concerning potential risks associated with it-this could facilitate better management strategies for autoimmune diseases along with appropriate adjustments in vaccination protocols. Although the precise triggering mechanism linking COVID-19-related events to AIH remains unclear, existing evidence suggests that this relationship is far from coincidental.

Antibodies directed against bacterial antigens in sera of Polish patients with primary biliary cholangitis

Background

Primary biliary cholangitis (PBC) is a cholestatic, autoimmune liver disease with the presence of characteristic autoantibodies. The aim of the work was to determine the level of antibodies directed against bacterial antigens: Chlamydia pneumoniae (anti-Cpn), Yersinia enterolitica (anti-Y.e), Helicobacter pylori (anti-Hp), Mycoplasma pneumoniae (anti- Mp.) and Escherichia coli (E.coli) in sera of PBC patients. We also performed in vitro studies on the impact of the bacterial peptides on the specific antigen-antibody binding.

Method

We screened 92 Polish PBC patients and sera samples from healthy donors and pathological controls. Autoantibodies and anti-bacterial antibodies were determined by commercially available ELISA kits. Specific inhibition of antibody binding was also detected by the in house ELISA method.

Results

Anti-Cpn, anti-Y. enterolitica, anti-Hp, anti-M. pneumoniae and anti-E. coli antibodies were significantly more common in the group of PBC patients than in the pathological and healthy control groups: 74%, 40%, 84%, 39% and 69% respectively. The mean level of anti-Cpn, anti- Y.e, anti-Hp and anti- M.p in the PBC group was significantly higher than those in the healthy group (p < 0.001). and in patients with other liver diseases. In sera of patients with the presence of positive anti-mitochondrial antibodies (AMA), specific for PBC, anti-bacterial antibodies have been found in 80% vs. 50% in sera with AMA negative. We observed inhibition of specific antigen-antibody binding by the bacterial peptide: EClpP (E. coli caseinolytic protease) and adenine glycosylase from E. coli caseinolytic protease P, ClpP Y.e from peptide of Y. enterolitica, Mp PDC from M. pneumonia peptide and adenine glycosylase of E. coli. Bacterial factors influence the specific binding of antibodies to pyruvate dehydrogenase (PDC-E2), gp210 and KLHL12 (kelch-like peptide 12) antigens.

Conclusion

Microbial mimics may be the major targets of cross-reactivity with human pyruvate dehydrogenase, gp210, and KLHL12 in PBC.

Peculiarity of Autoimmune Hepatitis Triggered by SARS-CoV-2 Infection

Introduction

Recently, medical interest has been growing in SARS-CoV-2 infection and its multiorgan involvement, including the liver. Up until now, a few reports have described autoimmune hepatitis (AIH) triggered by SARS-CoV-2 infection, but no data are available about the specific liver inflammatory infiltrate and cluster of differentiation. We report a case of AIH triggered by SARS-CoV-2 infection, with a particular focus on its histological and mainly immunohistochemical features.

Case description

A 60-year-old man, with a history of paucisymptomatic SARS-CoV-2 infection that occurred one month earlier, was admitted for alterations of hepatocellular necrosis and cholestasis indexes. He completed vaccination for SARS-CoV-2 a year earlier. The serologies for hepatotropic viruses were negative. The anti- smooth muscle antibodies (ASMA) and antinuclear antibodies (ANA) results were positive. Anti-liver kidney microsome (anti-LKM) antibodies and antimitochondrial (AMA) were negative. By liver biopsy, haematoxylin-eosin staining highlighted severe portal inflammation with a rich CD38+ plasma cell component, while immunohistochemical staining showed low cell CD4+ count and prevalence of CD8+ and CD3+. After biopsy, the patient started an immunosuppressant regimen, with benefit.

Discussion

We can conclude that the patient developed a type 1 AIH triggered by SARS-CoV-2 infection. The presence of CD8 T-cells at immunohistochemical examination suggests different mechanisms from classic AIH. Similar cases are described after AIH triggered by SARS-CoV-2 vaccination.

Conclusion

The AIH after SARS-CoV-2 infection developed by the patient showed a histological picture similar to a classic AIH for the abundant presence of plasma cells, and immunohistochemical features similar to those described after SARS-CoV-2-vaccination.

LEARNING POINTS

Recently, medical interest has been growing in SARS-CoV-2 infection and its multiorgan involvement, including the liver. Underlying mechanisms are not still clear, more likely consisting of an inflammatory and immune mediated process rather than a direct cytopathic damage.Our report describes a rare case of type 1 AIH triggered by SARS-CoV-2 infection, showing a peculiar histological pattern, different from classic AIH, conversely similar to AIH triggered by SARS-CoV-2 vaccination.The mechanisms underlying liver involvement in SARS-CoV-2 infection are still under investigation. Further studies should be encouraged to improve understanding on this focus and to support physicians in its management.

Autoimmune liver diseases and SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19), can trigger autoimmunity in genetically predisposed individuals through hyperstimulation of immune response and molecular mimicry. Here we summarise the current knowledge about auto-immune liver diseases (AILDs) and SARS-CoV-2, focusing on: (1) The risk of SARS-CoV-2 infection and the course of COVID-19 in patients affected by AILDs; (2) the role of SARS-CoV-2 in inducing liver damage and triggering AILDs; and (3) the ability of vaccines against SARS-CoV-2 to induce autoimmune responses in the liver. Data derived from the literature suggest that patients with AILDs do not carry an increased risk of SARS-Cov-2 infection but may develop a more severe course of COVID-19 if on treatment with steroids or thiopurine. Although SARS-CoV-2 infection can lead to the development of several autoimmune diseases, few reports correlate it to the appearance of de novo manifestation of immune-mediated liver diseases such as autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) or AIH/PBC overlap syndrome. Different case series of an AIH-like syndrome with a good prognosis after SARS-CoV-2 vaccination have been described. Although the causal link between SARS-CoV-2 vaccines and AIH cannot be definitively established, these reports suggest that this association could be more than coincidental.

Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?

BACKGROUND

There is an increasing number of liver injury cases resembling autoimmune hepatitis (AIH) following SARS-CoV-2 vaccination; however, an association has not yet been established.

METHODS/MATERIALS

A literature review was performed to identify articles regarding the association of AIH with vaccination, emphasizing on SARS-CoV-2 vaccines, and the proposed mechanisms. We then performed a literature search for AIH-like cases following SARS-CoV-2 vaccination, and we evaluated the included cases for AIH diagnosis using simplified diagnostic criteria (SDC), and for vaccination causality using the Naranjo score for adverse drug reactions.

RESULTS

We identified 51 AIH-like cases following SARS-CoV-2 vaccination. Forty cases (80%) were characterized as "probable", "at least probable", or "definite" for AIH diagnosis according to SDC. Forty cases (78.4%) were characterized as "probable", four (7.8%) as "possible", and three (5.8%) as "definite" for vaccine-related AIH according to the Naranjo score.

CONCLUSION

SARS-CoV-2 vaccine-related AIH carries several phenotypes and, although most cases resolve, immunosuppressive therapy seems to be necessary. Early diagnosis is mandatory and should be considered in any patient with acute or chronic hepatitis after SARS-CoV-2 vaccination, especially in those with pre-existing liver disease.

New-onset and relapsed liver diseases following COVID-19 vaccination: a systematic review

BACKGROUND

Liver diseases post-COVID-19 vaccination is extremely rare but can occur. A growing body of evidence has indicated that portal vein thrombosis, autoimmune hepatitis, raised liver enzymes and liver injuries, etc., may be potential consequence of COVID-19 vaccines.

OBJECTIVES

To describe the results of a systematic review for new-onset and relapsed liver disease following COVID-19 vaccination.

METHODS

For this systematic review, we searched Proquest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses PRISMA guideline for studies on the incidence of new onset or relapsed liver diseases post-COVID-19 vaccination, published from December 1, 2020 to July 31, 2022, with English language restriction.

RESULTS

Two hundred seventy-five cases from one hundred and eighteen articles were included in the qualitative synthesis of this systematic review. Autoimmune hepatitis (138 cases) was the most frequent pathology observed post-COVID-19 vaccination, followed by portal vein thrombosis (52 cases), raised liver enzymes (26 cases) and liver injury (21 cases). Other cases include splanchnic vein thrombosis, acute cellular rejection of the liver, jaundice, hepatomegaly, acute hepatic failure and hepatic porphyria. Mortality was reported in any of the included cases for acute hepatic failure (n = 4, 50%), portal vein thrombosis (n = 25, 48.1%), splanchnic vein thrombosis (n = 6, 42.8%), jaundice (n = 1, 12.5%), raised liver enzymes (n = 2, 7.7%), and autoimmune hepatitis (n = 3, 2.2%). Most patients were easily treated without any serious complications, recovered and did not require long-term hepatic therapy.

CONCLUSION

Reported evidence of liver diseases post-COIVD-19 vaccination should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively very small in relation to the hundreds of millions of vaccinations that have occurred and the protective benefits offered by COVID-19 vaccination far outweigh the risks.