[The development of Graves' disease after long-term hypothyroidism due to Hashimoto's disease]

The main autoimmune thyroid diseases are Hashimoto's thyroiditis (HT) and Graves' disease (GD). Despite the significant differences in a pathogenesis and a clinical picture between HT and GD, the literature describes the cases of the conversion of one autoimmune disease to another, which, according to one version, is associated with a change in the balance between the levels of a stimulating and blocking antibodies to the thyroid-stimulating hormone receptor. At the same time, there are more frequent observations of the transition of GD to HT, and much less often describe, on the contrary, the development of GD against the background of HT. The article presents a clinical case of the conversion of HT to GD. A detailed algorithm of the conservative management according to the «block-replace» scheme is described, indicating the results of laboratory and instrumental examination. At the time of describing the clinical case, the result of the treatment can be considered successful. The predictors such as a low level of the thyroid-stimulating hormone receptor and thyroid volume before discontinuation of the thyrostatic therapy suggest a low risk of the recrudescence of GD.According to the authors, the phenomenon of the conversion of one autoimmune thyroid disease to another, in addition to the scientific interest, is important for the practitioners, since a timely change in the diagnostic paradigm can significantly change the treatment strategy and the favorably affect the prognosis of disease, preventing the development of complications.