Thyroid axis and COVID 19

Introduction: Non-thyroidal illness syndrome (NTIS) is also known as low T3 syndrome NTIS is characterized by low plasma T3, low or normal T4, or elevated reverse T3 (rT3), with normal or slightly decreased TSH NTIS is a strong predictor of poor prognosis in critically ill hospitalized patients Different thyroid hormone profiles were defined during critical illness High fT4 with a low fT3 level in patients with coronary heart disease were significantly related to mortality If NTIS is a physiologic response to a systemic inflammation or a maladaptation status is controversial NTIS with low fT3 and a lower fT3/fT4 ratio was referred in patients with COVID-19 Furthermore, angiotensin-converting enzyme (ACE) 2, an receptor in the pathogenesis of COVID-19, was demonstrated to be expressed in the thyroid gland SARS-CoV-2- related thyroiditis is recognized The effects of COVID-19 on the thyroid axis remain uncertain Objectives: We aimed to study the characteristics of thyroid hormone levels in inpatients with COVID-19 Methods: Prospective study: 57 covid-19 patients (29/57 ♂) with criteria for admission to a medical clinic from August to November 2020 Median age was 56 years (range(R) : 21-89) 3,6% was asymptomatic, 14,3% mild, 28,6% moderate and 53,6% severe fT4, TT3, TSH, TgAb and TPOAb were analysed in addition to studies due to their underlying pathology Data are expressed as median and R or mean ± SD and % Results: The median of TSH was 1 77 uUI/ml (R: 0 02-64 9), the X ± SD of fT4 and TT3 was 1 22 ± 0 3 ng/ml and 72 3 ± 23 04 ng/dl respectively Forty two/ 57 patients presented low T3 The profiles observed in this group are described in table 1 Two patients with positive TPOAb had high TSH, low T3 and normal fT4 and 3 only low T3 Image: Conclusion: 1-In this population of COVID-19 patients upon admission to hospitalization and excluding one clinical hypothyroid patient 73, 7% presented low T3 2- In the patient with clinical hypothyroidism and negative antibodies as well as those with altered TSH, low TT3 and normal or high fT4 we cannot exclude destructive or autoinmune thyroiditis until the evolution is known 3-Classic NTI with low T3, low o normal fT4 and nomal TSH was observed in 42, 1% patients 4- It should be noted the high prevalence of patients with low TT3, high fT4 and normal TSH We consider that is another face of NTI in COVID-19 as it was referred in patients with coronary disease To our knowledge, this is the first descriptive report of different faces of NTI in COVID 19 patients