Patients With Autoimmune Thyroiditis Present Similar Immunological Response to COVID-19 BNT162b2 mRNA Vaccine With Healthy Subjects, While Vaccination May Affect Thyroid Function: A Clinical Study.

Background: This is the first study, that aimed: a) to compare immune response, namely the kinetics of neutralizing antibodies (Nabs), after vaccination with BNT162b2 mRNA vaccine (Comirnaty, Pfizer/BioNTech) between patients with autoimmune thyroiditis and controls, and b) to investigate changes in thyroid function in healthy subjects with no history of thyroid dysfunction before and after vaccination with BNT162b2 mRNA vaccine (Comirnaty, Pfizer/BioNTech). Methods: The entire study consisted of two sub-studies. In the first sub-study, NAbs levels after BNT162b2 mRNA vaccination were compared between 56 patients with autoimmune thyroiditis and 56 age and gender-matched healthy controls from the day of the first dose until a period of up to three months after the second dose. In the second sub-study, thyroid hormones (T3, T4, TSH) and thyroid auto-antibodies levels (anti-TG, anti-TPO) of 72 healthy subjects with no history of thyroid disease were examined before (D1) and one month after completion of the second dose (D50). Results: Among patients with autoimmune thyroiditis, the median neutralizing inhibition on D22, immediately before second dose, was 62.5%. One month later (D50), values increased to 96.7%, while three months after the second dose NAbs titers remained almost the same (94.5%). In the healthy group, median NAbs levels at D22 were 53.6%. On D50 the median inhibition values increased to 95.1%, while after three months they were 89.2%. The statistical analysis did not show significant differences between two groups (p-values 0.164, 0.390, 0.105 for D22, D50 and three months). Regarding changes in thyroid function, the mean value for T4 before vaccination was 89.797 nmol/L and one month after the second dose was 89.11 nmol/L (p-value=0.649). On D1 the mean T3 value was 1.464 nmol/L, which dropped to 1.389 nmol/L on D50 (p-value = 0.004). For TSH, mean levels were 2.064 mIU/ml on D1 and fell to 1.840 mIU/ml one month after the second dose (p-value=0.037). Despite decrease, all thyroid hormone levels remained within the normal range. No changes were found for anti-TPO or anti-TG. Conclusions: This study provided evidence that patients with autoimmune thyroiditis present similar immunological response to COVID-19 BNT162b2 mRNA vaccine (Comirnaty, Pfizer/BioNTech) with healthy subjects, while vaccination may affect thyroid function.

A Prospective Observational Study of 42 Patients with COVID-19 infection and a History of Hepatitis C Virus Infection and Thyroid Disease with Follow-Up Thyroid Function and Autoantibody Testing.

BACKGROUND Thyroiditis is an important extrahepatic association in chronic hepatitis C virus (HCV) infection. There have been reports of an association between SARS-CoV-2 infection and the onset or re-activation of autoimmune hypothyroidism. Therefore, we performed this prospective observational study of 42 patients with COVID-19 infection and a history of hepatitis C virus infection and thyroid disease with follow-up thyroid function and autoantibody testing. MATERIAL AND METHODS From April 2020 to October 2020, we performed a prospective observational study of patients with cured hepatitis C virus (HCV) infection and documented thyroid disease who became infected with SARS-CoV-2 (confirmed by SARS-CoV-2 RNA detection via reverse-transcription polymerase chain reaction [RT-PCT] from the upper respiratory tract, both nasal and pharyngeal swabs). Evaluation at 1 and 3 months after SARS-CoV-2 infection included serum determination of antithyroid antibodies (anti-thyroglobulin [anti-Tg] and antithyroid peroxidase [ATPO]), thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and evaluation of thyroid medication, with dose adjustment if required. RESULTS One-month follow-up showed that both patients with autoimmune thyroiditis as well as patients without antibodies had increased ATPO levels. Also, levels of TSH, fT3, and fT4 were significantly decreased. At 3-month follow-up, levels of ATPO were decreased in all patient groups and the levels of thyroid hormones increased to normal values. CONCLUSIONS This study supports previous reports of an association between SARS-CoV-2 infection and thyroid dysfunction associated with thyroid autoantibodies. Thyroid function tests may be considered as part of the laboratory work-up in patients with COVID-19.