Postvaccine early-onset (PoVEO) forms of Graves' disease after anti-SARS-CoV-2 vaccination are characterized by favourable long-term disease outcomes

Introduction: In a previous cohort of patients with new-onset of Graves' Disease (GD) during 2021, a "postvaccine early-onset (PoVEO)" after anti-COVID-19 vaccination emerged as a new and frequent nosological entity occurring in approximately one third of patients. Similar cohorts have also been reported with GD after anti-COVID vaccines, but to date there are no available data on long-term clinical outcomes. Methods: This is a single-center retrospective study evaluating the 24-month clinical course of patients with early-onset (<4 weeks) GD after anti-COVID vaccination (PoVEO) compared to non-PoVEO patients. Biochemical tests, therapies used and follow-up visits were scheduled according to current guidelines, clinicians' experience and patients' needs. Results: As previously described, 64 patients were observed in 2021 and 20 (31.2%) had PoVEO. Individuals with PoVEO were characterized by distinctive features such as older age, a higher prevalence of male sex, and a better initial biochemical response. Eleven individuals were followed at other Centers (2 with PoVEO and 9 without) and were lost to follow-up. During the two-year follow-up, of the 53 individuals, 7 (13%) underwent definitive surgical or radioactive-iodine therapy (3 PoVEO and 4 non-PoVEO p = 0.67), and 30 (57%) presented disease remission with medical therapy alone. Excluding those who underwent definitive treatments, remission with medical therapy alone was observed in 13/15 (87%) individuals with PoVEO form and 17/31 (55%) non-PoVEO (p = 0.048). Conclusion: In this retrospective study of a cohort of individuals with the PoVEO form of GD, we found a more favourable clinical course, likely linked to transience of the triggering events. Despite these findings, individuals presenting with GD after SARS-CoV-2 vaccination should undergo an active surveillance program with repeat thyroid function testing.