Comparison of the clinical characteristics of new onset Graves’ disease before and during the Coronavirus disease 2019 era

Abstract Introduction The aim of this study was to compare the clinical, biochemical, and disease control characteristics of newly diagnosed Graves’ disease (GD) before and during the coronavirus disease 2019 (COVID-19) era. Methods In this retrospective, single-center observational study, 95 patients with newly diagnosed GD between January 2015 and November 2024 were evaluated for thyroid function, autoantibody levels, antithyroid drug (ATD) doses, and disease control status. Patients diagnosed before January 2019 were classified as the pre-COVID-19 group (n=46), whereas those diagnosed after March 2020 were classified as the COVID-19 era group (n=49); patients diagnosed between January 2019 and March 2020 were excluded due to potential classification ambiguity. Only patients treated with ATD for at least 12 months were included in the analysis. Results Patients diagnosed during the COVID-19 era had higher thyroglobulin antibody (TgAb) titers at diagnosis (p=0.001) and higher free thyroxine levels at 12 months and at the final visit (p=0.001). Although the time to euthyroidism was lower in the COVID-19 era group, the difference was not statistically significant. End-of-treatment thyrotropin receptor antibody (TRAb) levels were similar between groups; however, fewer patients in the COVID-19 era group achieved TRAb normalization. Disease control rates and time to achieve disease control under ATD therapy were comparable between the two groups. Among patients diagnosed during the COVID-19 era, 89.8% received at least one messenger RNA vaccine dose, and 40.8% had a positive polymerase chain reaction test. Conclusion The COVID-19 era was not associated with a major change in the overall clinical course of GD . However, patients diagnosed during the COVID-19 era had higher TgAb levels at diagnosis and incomplete TRAb normalization in some cases, suggesting subtle differences in thyroid immuneactivity.