hrp0094p2-477 | Thyroid | ESPE2021

L-T4 absorption test in 14-year-old patient with severe refractory hypothyroidism after total thyroidectomy

Vincenzi Gaia , Di Stefano Marina , Abbate Marco , Tarantola Giulia , Barera Graziano , Vigone Maria Cristina

Hypothyroid patients post-thyroidectomy require 1.6-1.8 mg/kg/die of Levothyroxine (L-T4). A persistent TSH level above the upper limit despite a daily dose >1.9 mg/kg/die is defined as “refractory” hypothyroidism in adults. Malabsorption and “pseudo-malabsorption” need to be investigated in case of therapeutic failure. L-T4 absorption test (LT4AT) is useful in distinguishing these two conditions but it has only been described in adult age. We ...