Immune-mediated inflammatory diseases after anti-SARS-CoV-2 vaccines: new diagnoses and disease flares

Objective: New-onset immune-mediated inflammatory diseases (IMIDs) and flares of pre-existing IMIDs have been reported following anti- SARS-CoV2 vaccination. Our study aimed at describing a retrospective cohort of patients developing new-onset IMIDs or flares of known IMIDs within 30 days after any anti-SARS-CoV2 vaccine dose. Methods: We evaluated clinical records of all inpatients and outpatients referring to our institution between February 2021 and February 2022 with any clinical manifestations. We then selected those having received any anti-SARS-CoV2 vaccine dose within the prior 30 days and classified them as having or not a previous IMID according to predefined criteria. We recorded new-onset IMIDs or flares of known IMIDs and investigated any relationship with demographic, clinical and serological variables. Results: 153 patients that received any anti-SARS-CoV2 vaccine dose within the previous 30 days were included of which 45 (29%) already had a diagnosis of IMID while 108 (71%) had no previously diagnosed IMID. 33 (30%) of the 108 patients, were diagnosed with a new-onset IMID. Pericarditis, polymyalgia rheumatica and vasculitis were the most frequent conditions. Among the 45 patients that already had an IMID, disease flare was the reason for referral in 69% of patients. Patients with an IMID flare had a lower number of comorbidities and tended to be younger compared with those who developed other conditions after anti-SARS-CoV2 vaccination. Conclusion: We provided a retrospective overview of a cohort of patients who developed new-onset IMIDs or flares of known IMIDs within 30 days after any dose of anti-SARS-CoV2 vaccine. While vaccination campaigns proceed, postvaccination surveillance programmes are ongoing and hopefully will soon clarify whether a causal relationship between vaccines and new-onset/flares of IMIDs exists.