Diagnostic features of autoimmune hepatitis in SARS‑CoV‑2‑vaccinated vs. unvaccinated individuals

The global coronavirus disease 2019 (COVID‑19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), has affected millions of lives, leading to significant morbidity and mortality. With >772 million cases and nearly seven million deaths reported worldwide to date, the development of vaccines has been a critical step in mitigating the impact of COVID‑19. However, concerns have arisen regarding the potential for SARS‑CoV‑2 mRNA vaccination to trigger autoimmune diseases, including autoimmune hepatitis (AIH). The present single‑center, retrospective study aimed to compare the clinical and pathological features of AIH in patients with or without a history of SARS‑CoV‑2 mRNA vaccination. A total of 72 patients with AIH were examined. Among them, 10 had received the SARS‑CoV‑2 mRNA vaccination prior to AIH onset. These patients exhibited more pronounced CD4⁺ T cell infiltration into the liver tissue compared with those who were unvaccinated. No significant differences in the levels of other liver enzymes, autoimmune antibodies, or CD8⁺T cell infiltration were observed between the groups. Moreover, the AIH patients with a history of SARS‑CoV‑2 mRNA vaccination had more extensive CD4⁺ T cell infiltration in their liver tissues than the unvaccinated patients. These findings suggested that the immune response to SARS‑CoV‑2 mRNA vaccination may influence the pathogenesis of AIH, highlighting the need for further research into the relationship between SARS‑CoV‑2 mRNA vaccination and autoimmune liver diseases. Such studies will also help clarify the distinction between vaccine‑induced liver injury and traditional AIH.