COVID-19 Vaccination May Trigger AAV as Possible Side Effect: Study

ANCA cases in Spain more than double after mass vaccinations

Vanda Pinto, PhD avatar

by Vanda Pinto, PhD |

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COVID-19 vaccination side effects | ANCA Vasculitis News | vaccination illustration

The number of ANCA-associated vasculitis (AAV) cases in Spain more than doubled between 2019 and 2021 following mass-scale vaccination against SARS-CoV-2, the virus that causes COVID-19, a new study found, suggesting the vaccine as a possible trigger.

Researchers suspect the development of ANCA antibodies and AAV could be among the side effects of COVID-19 vaccination.

“To our knowledge this is the largest study that [includes] patients who debuted with ANCA and AAV during 2021 after receiving vaccination against SARS-CoV-2 without suffering from COVID-19, in comparison with 2019, before the COVID-19 pandemic,” the team wrote.

Four of the new AAV patients did in fact contract COVID-19, but the researchers noted that all of them developed ANCA “after vaccination and before the viral infection.”

The study, “Increased induction of de novo serum ANCA and ANCA-associated vasculitis after mass vaccination against SARS-CoV-2,” was published in the journal iScience.

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Janssen COVID-19 Vaccine Linked to AAV-related Kidney Damage

In AAV, anti-neutrophil cytoplasmic antibodies, or ANCAs, mistakenly bind and activate white blood cells called neutrophils. Overactivation of neutrophils promotes inflammation and damage to small blood vessels.

The autoimmune disease causes a range of symptoms, depending on which organs and tissues are affected. Kidney damage and inflammation occur in many AAV cases.

Possible side effects of COVID-19 vaccination

A few reports have emerged recently of patients who developed AAV after being vaccinated against COVID-19.

Now, a team of scientists in Spain sought to determine the incidence of AAV before the mass administration of COVID-19 vaccines in that country in 2019 and after, in 2021.

Included in the study were individuals who tested positive for the presence of ANCA antibodies, specifically those that target the proteins proteinase 3 (PR3) and myeloperoxidase (MPO).

Patients who had anti-glomerular basement membrane (GBM) antibodies, which are associated with kidney damage, also were included.

ANCA and/or anti-GBM antibodies were detected in a total of 15 people in 2019 and in 35 patients in 2021, despite a similar overall number of tests being conducted in these two years. Altogether, there were 1,287 patients tested in 2019 and 1,434 in 2021.

“Our case series is the largest series reported on new cases of patients with ANCA after SARS-CoV-2 vaccination,” the researchers wrote.

The frequency of anti-PR3 antibodies increased from 20.0% in 2019 to 45.8% in 2021, while it dropped for anti-MPO antibodies (from 80% to 51.5%). However, the researchers could not explain this finding.

In 2019, anti-GBM antibodies were detected in one patient, compared with two in 2021.

More than half of the patients (54.3%) received three doses of the Pfizer-BioNTech (BNT162b2) vaccine, while others were given the Moderna, AstraZeneca, or Janssen vaccines, or a combination of them.

Two patients developed ANCA after receiving the first dose (7.4%) of the COVID-19 vaccine; in each of these cases, the Pfizer-BioNTech vaccine was used. Another 25 individuals were diagnosed with ANCA after receiving the second dose of the vaccine (92.6%). A total of eight people had ANCA antibodies before being vaccinated.

Four patients tested positive for SARS-CoV-2 infection after vaccination.

ANCA affected multiple organs in almost all patients (97.1%) who were diagnosed in 2021. The team noted the kidneys and lungs were the organs most frequently impacted. Additionally, while in 2019 there were no reports of eye or gastrointestinal manifestations, these symptoms appeared for the first time in 2021.

“An increase in the development of AAV has been observed during 2021 in comparison with 2019, which could be due to the administration of SARS-CoV-2 vaccine,” the team wrote, suggesting that the spike was among the possible side effects of COVID-19 vaccination.

However, investigators added that “whether the association between SARS-CoV-2 vaccine and autoimmune manifestations is coincidental or causal remains to be elucidated. Further studies and longer-term follow-up studies are necessary to elucidate the underlying mechanisms and identify the exact cause of these autoimmune manifestations.”