Increased Induction of Serum Anti-Neutrophil Cytoplasmic Antibodies After Mass Vaccination Against SARS-CoV-2

Mass vaccination against SARS-CoV-2 has been the most effective strategy to combat against SARS-CoV-2 infection, conferring protection and reducing hospitalization and mortality. Severe related adverse events have been rare. However, different immune-mediated diseases, including cases of glomerulonephritis (GN) have been reported, being antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis one of the possible side effects caused by the mass-scale vaccination Therefore, knowing the incidence of new ANCA patients after vaccination is an aspect of great relevance. A total of 35 patients presented ANCA and/or anti-MBG antibodies for the first time during 2021, being this number of 15 during 2019, before the pandemic. In 2019, the most frequent ANCA was anti-MPO being present in 80.0% of the patients. However, in 2021 an increase in the positivity for anti-PR3 antibody was observed, which was presented in 45.7% of the patients. 27 out of 35 patients developed ANCA after vaccination. Two of them developed these antibodies after receiving the first dose (7.4%), being BNT162b2 the vaccine administrated in these cases, and 25 patients developed ANCA after the second dose of the vaccine (92.6%), being BNT162b2 the main vaccine received by these patients. In 97.1% of the patients who developed ANCA during 2021, the positivity of ANCA was accompanied by systemic involvement, being renal and respiratory tracts the main organs affected. Therefore, an increase in the development of ANCA has been observed during 2021 in comparison with 2019, which could be due to the administration of SARS-CoV-2 vaccine.Funding Information: This research received no external funding.Conflict of Interests: All the authors declared no competing interests.Ethical Approval: The study was conducted according to the guidelines of the Declaration of Helsinki and it was approved by the Regional Ethics Committee (CEIm, internal code 2020.167, 14 May 2020).