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

We read an interesting article entitled “SARS-CoV-2 vaccination can elicit a CD8⁺ T-cell dominant hepatitis” by Boettler et al., recently published in the Journal of Hepatology, demonstrating SARS-CoV-2-specific T-cell-dominant immune-mediated hepatitis after vaccination. This phenomenon may account for the association between SARS-CoV-2 vaccination and autoimmune hepatitis (AIH)-like conditions including overlap syndrome. Herein, we describe a case of overlap syndrome after SARS-CoV-2 vaccination.

Case: A 57-year-old woman without a history of medical diseases and taking hepatotoxic drugs or alcohol was referred to the clinic for general weakness. She used to have normal liver function tests in a routine medical check-up. Two weeks after the first dose of SARS-CoV-2 Pfizer/BioNTech BNT162b2 mRNA vaccine, she started developing fatigue and general weakness. Her physical examination was normal; however, laboratory tests were significant for total bilirubin, 1.2 mg/dl; aspartate aminotransferase, 635 U/L; alanine aminotransferase, 870 U/L; alkaline phosphatase, 250 U/L; gamma-glutamyl transferase, 210 U/L; and international normalized ratio, 1.02. Laboratory results were negative for hepatitis A, B, C, and E, Epstein-Barr virus (EBV), cytomegalovirus, and herpes simplex virus (HSV) types 1 and 2. Autoantibody tests were positive for antinuclear antibody (ANA, 1:160; homogeneous pattern) and anti-mitochondrial M2 antibody (AMA-M2), while the test for anti-smooth muscle antibody was negative. The immunoglobulin G level was 1,532 mg/dl (normal range: 800–1,800 mg/dl). Abdominal ultrasound findings were normal, without evidence of abnormal findings in the biliary tract and liver. A percutaneous liver biopsy was performed, revealing moderate portal inflammation with CD3⁺ T-cell-dominant infiltration along with CD38⁺ cells suggesting plasma cells, interface hepatitis, rosette formation, and piecemeal necrosis. Moreover, nonsuppurative and granulomatous cholangitis with destruction and proliferation of the bile duct, was also noted, which was compatible with the findings of overlap syndrome (Fig. 1A).^, Taken together, the revised original score for AIH was 13 (results ≥10 suggest probable AIH) and the Paris criteria for AIH-primary biliary cholangitis (PBC) overlap syndrome was satisfied.^, After treatment with high-dose ursodeoxycholic acid (13 mg/kg), her laboratory findings normalized in 2 weeks (Fig. 1B).

Several reports have documented the possibility of an association between the development of AIH and SARS-CoV-2 vaccination or infection.^, This association has been thought to be attributable to molecular mimicry between the spike protein S1 of SARS-CoV-2, a viral protein coded by the mRNA vaccine, and human tissue proteins.^, Finally, Boettler et al. successfully demonstrated that AIH-like conditions could be caused by activated CD8⁺ T cells, including vaccine-induced spike-specific CD8⁺ T cells. These novel findings provide insights into the strong association between the development of AIH-like hepatitis and SARS-CoV-2 vaccination, which can also be applied to our case.

In our patient, CD3⁺ T cells were also dominant among the infiltrating inflammatory cells of the portal area. Although virus-specific CD8⁺ T cells were not identified in our case, most of the infiltrated T cells might be SARS-CoV-2 specific CD8⁺ T cells according to the results of Boettler et al., which could be attributable to the development of overlap syndrome in our case. Interestingly, in our patient, non-suppurative and granulomatous cholangitis with destruction and proliferation of the bile ducts was identified, suggesting the presence of combined PBC.^,, As PBC also develops with the interaction of immune and biliary pathways, including recruited CD4⁺ and CD8⁺ T cells, SARS-CoV-2-specific CD8⁺ T cells might have contributed to the development of overlap syndrome in our patient following SARS-CoV-2 vaccination. In conclusion, our case supports the notion that SARS-CoV-2-specific T cells can cause AIH-like conditions, including overlap syndrome, after SARS-CoV-2 vaccination.