3. Discussion
Several reports have described a relationship between COVID-19 and
thyroid disorders such as subacute thyroiditis, autoimmune thyroiditis
and Graves’ disease [4–6]. In a retrospective single-center study
by Lania[7], 20.2% in their cohort were found to have
thyrotoxicosis. Serum TSH levels were inversely correlated with age and
IL-6 levels.
Autoimmune thyroiditis is one of the most common thyroid disorders in
South East Asia [8,9]. In this condition, detectable anti-thyroid
antibodies such as anti-thyroid peroxidase (anti -TPO) and
anti-thyroglobulin antibodies (anti -Tg) are present in the seraof
most patients. Anti -Tg antibodies were undetectable in our
patient pre-COVID-19 infection, but were found after the infection had
resolved, as in a number of similar cases in other countries [10].
Graves’ disease is the most common cause of hyperthyroidism in South
East Asia [8,9]. It is also an autoimmune thyroid disease in which
the presence of thyroid receptor antibody (TRAb) and a low or
undetectable TSH level are typical. Most reported case series of
hyperthyroidism during active COVID-19 infection suggest that a
destructive viral thyroiditis contributes to the clinical presenation of
subacute thyroiditis [4–7,11–13]. An autopsy study in COVID-19
patients showed destruction of the follicular and parafollicular cells
of the thyroid [14]. Our literature search revealed reports of
thyroid disorders occurring after COVID-19 infection are sparse and as
far as we are aware, this is the first case of new-onset Graves’ disease
post COVID-19 in Vietnam. However, several cases reported recently have
shown new-onset of Graves’ disease as the cause of hyperthyroidism in
patients after COVID-19 infection [15–17]. Reelevant demographic
and clinical characteristics of each included patient are summarized in
Table 2
Table 2
Description of the demographic characteristics and clinical presentation
of COVID-19 triggered Graves’ disease