MONDAY, March 22, 2021 (HealthDay News) -- At three months after COVID-19 disease, patients have normalized thyroid function, but subacute thyroiditis may be present, according to a study presented at the annual meeting of The Endocrine Society, held virtually from March 20 to 23.
Noting that patients hospitalized with COVID-19 may have occurrence of thyrotoxicosis due to atypical subacute thyroiditis with significantly lower median serum thyroid-stimulating hormone (TSH) concentration, Ilaria Muller, M.D., Ph.D., from the University of Milan, and colleagues conducted a longitudinal follow-up study of COVID-19 patients to assess serum thyroid function and autoantibodies, C-reactive protein (CRP), full blood count (FBC), and thyroid ultrasound every three months.
Fifty-three patients were included in the follow-up study. The researchers found that all patients presented with increased median serum TSH concentration at three months after infection versus baseline (1.3 versus 0.9 mIU/L). Compared with baseline, serum concentrations of free-thyroxine, free-triiodothyronine, CRP, and FBC had normalized. All patients had negative autoantibodies to TSH receptor, while 11 and 9 percent were positive for autoantibodies to thyroglobulin and thyroid peroxidase, respectively. Focal hypoechoic areas of thyroiditis were seen on thyroid ultrasound in 32 percent of patients. Thyroid uptake on thyroid 99m-Tc or I-123 studies was normal, focally reduced, and diffusely reduced in 37, 50, and 12 percent of patients, respectively.
"We are continuing to monitor these patients to see what happens during the following months," Muller said in a statement. "It is important to know whether severe acute respiratory syndrome coronavirus 2 has late-onset negative effects on the thyroid gland, in order to promptly diagnose, and eventually treat, the condition."