Autoimmune hepatitis after COVID-19 vaccine - more than a coincidence.

The COVID-19 pandemic is still raging across the world and vaccination is expected to lead us out of this pandemic. Although the efficacy of the vaccines is beyond doubt, safety still remains a concern. We report a case of a 65-year-old woman who experienced acute severe autoimmune hepatitis two weeks after receiving the first dose of Moderna-COVID-19 vaccine. Serum immunoglobulin G was elevated and antinuclear antibody was positive (1:100, speckled pattern). Liver histology showed a marked expansion of the portal tracts, severe interface hepatitis and multiple confluent foci of lobular necrosis. She started treatment with prednisolone, with a favorable clinical and analytical evolution. Some recent reports have been suggested that COVID-19 vaccination can lead to the development of autoimmune diseases. It is speculated that the vaccine can disturb self-tolerance and trigger autoimmune responses through cross-reactivity with host cells. Therefore, healthcare providers must remain vigilant during mass COVID-19 vaccination.

Interaction of Genetic Variations in NFE2L2 and SELENOS Modulates the Risk of Hashimoto's Thyroiditis.

Background: Several single-nucleotide polymorphisms (SNPs) are known to increase the risk of Hashimoto's thyroiditis (HT); such SNPs reside in thyroid-specific genes or in genes related to autoimmunity, inflammation, and/or cellular defense to stress. The transcription factor Nrf2, encoded by NFE2L2, is a master regulator of the cellular antioxidant response. This study aimed to evaluate the impact of genetic variation in NFE2L2 on the risk of developing HT. Methods: In a case-control candidate gene association study, functional SNPs in the NFE2L2 promoter (rs35652124, rs6706649, and rs6721961) were examined either as independent risk factors or in combination with a previously characterized HT risk allele (rs28665122) in the gene SELENOS, encoding selenoprotein S (SelS). A total of 997 individuals from the north of Portugal (Porto) were enrolled, comprising 481 HT patients and 516 unrelated healthy controls. SELENOS and NFE2L2 SNPs were genotyped using TaqMan® assays and Sanger sequencing, respectively. Odds ratios (ORs) were calculated using logistic regression, with adjustment for sex and age. Expression of SelS was analyzed by immunohistochemistry in thyroid tissue from HT patients and control subjects. Molecular interactions between the Nrf2 and SelS pathways were investigated in thyroid tissues from mice and in rat PCCL3 thyroid follicular cells. Results: When all three NFE2L2 SNPs were considered together, the presence of one or more minor alleles was associated with a near-significant increased risk (OR = 1.43, p = 0.072). Among subjects harboring only major NFE2L2 alleles, there was no increased HT risk associated with heterozygosity or homozygosity for the SELENOS minor allele. Conversely, in subjects heterozygous or homozygous for the SELENOS risk allele, the presence of an NFE2L2 minor allele significantly increased HT risk by 2.8-fold (p = 0.003). Immunohistochemistry showed reduced expression of SelS in thyroid follicular cells of HT patients. In Nrf2 knockout mice, there was reduced expression of SelS in thyroid follicular cells; conversely, in PCCL3 cells, reducing SelS expression caused reduced activity of Nrf2 signaling. Conclusions: The NFE2L2 promoter genotype interacts with the SELENOS promoter genotype to modulate the risk of HT in a Portuguese population. This interaction may be due to a bidirectional positive feedback between the Nrf2 and SelS pathways.