Endocrine Abstracts

Introduction: Autoimmune thyroid diseases are frequent and very polymorphic pathologies. The same person can successively present with different manifestations. Graves’ disease and Hashimoto’s thyroiditis seem to be able to coexist. The name "Hashitoxicosis" has been suggested in this case, characterized by the sequential association, whatever the order, of hyper- and hypothyroidism. We report in this work, the case of a patient treated for autoimmune hypothyroidism and who subsequently presented with Graves’ disease.

Observation: Aged 38, our patient presented at the age of 33 with autoimmune hypothyroidism and she was put on Levothyroxine for a period of 4 years. Considering her falling TSH levels at each quarterly check-up, we had to stop the replacement opotherapy, a few months later, another TSH level came back down to 0.001 µui/ml with an FT4 of 22 pmol/ml, and an FT3 at 8 pmol/l, with an autoimmunity assessment in favour of Graves’ disease with a TSI level > 40 ui/l and TPO antibodies >453 ui/l. The thyroid ultrasound revealed a thyroid of normal volume with heterogeneous echogenicity, without Doppler hyperaemia, completed by a thyroid scintigraphy that returned in favour of diffuse toxic goiter, suggesting Graves’ disease. The patient was put on Antithyroid drugs.

Conclusion: The close relationship of these two forms of autoimmune thyroid disease explains the possible transition from one to the other, with successive phases of hyper-, eu- and hypothyroidism, linked to alterations of the balance between the various classes of antibodies.