Endocrine Abstracts

Background: A possible association between severe acute respiratory syndrome coronavirus (SARS-CoV)-2 pandemic and subacute thyroiditis (SAT) has been reported.

Objectives: To evaluate SAT clinical characteristics, correlating them to virus exposure and/or vaccine and to evaluate thyroid function according to the length of time after symptoms onset.

Methods: We performed a prospective, observational, multi-centre study, considering three Italian centres. Patients with documented SAT diagnosis were enrolled from November 2020 to May 2022 and followed up for 12 months. SARS-CoV-2 infection (i.e. positive rhino-pharyngeal swab obtained within 3 months before SAT onset) and vaccination were recorded. This interim analysis was performed considering the visit performed at diagnosis.

Results: A total of 67 subjects (79.1% F, 20.9% M) were enrolled (age: 49.9+12.9 years). The cohort was divided considering the time between symptoms onset and endocrinological evaluation: Group1 included patients who underwent visit within 15 days (44.8%), whereas Group2 those who delayed visit beyond 15 days (55.2%). No difference in inflammation indexes and thyrotoxicosis rate (70.0% vs 70.3%, P = 0.381) was found between groups. Hypothyroidism rate was higher in Group2 than in Group1 (8.1% vs 0.0%, P = 0.004). The entire cohort was divided according to either SARS-Cov2 infection (13 patients–19.4%) or vaccination (23 patients–34.3%). Thyrotoxicosis rate and inflammation indexes were not significantly different between patients with or without SARS-Cov2 infection and/or vaccination. At multinomial logistic regression analyses, thyrotoxicosis was predicted by erythrocyte sedimentation rate (ESR) elevation (P < 0.001), SARS-CoV-2-vaccination (P = 0.002) and respiratory symptoms (P < 0.001).

Conclusions: Neither SARS-CoV-2 infection nor vaccination affected the clinical SAT presentation. However, SAT-related thyrotoxicosis was predicted by ESR elevation, vaccination, and respiratory symptoms.