Induction of autoimmune hypothyroidism and subsequent hyperthyroidism by TSH receptor antibodies following subacute thyroiditis: A case report

Citation
M. Iitaka et al., Induction of autoimmune hypothyroidism and subsequent hyperthyroidism by TSH receptor antibodies following subacute thyroiditis: A case report, ENDOCR J, 48(2), 2001, pp. 139-142
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
ENDOCRINE JOURNAL
ISSN journal
0918-8959 → ACNP
Volume
48
Issue
2
Year of publication
2001
Pages
139 - 142
Database
ISI
SICI code
0918-8959(200104)48:2<139:IOAHAS>2.0.ZU;2-N
Abstract
A 45 year-old man had a typical episode of subacute thyroiditis with tender goiter, depressed radioiodine uptake (RAIU) and elevated erythrocyte sedim entation rate. The titer of TSH binding inhibitor immunoglobulin (TBII), wh ich had been 8.6% at initial presentation, rose to 14.9% in 2 weeks. TBII c onsisted of high titers (94%) of TSH stimulation-blocking antibodies (TBAb) and negative thyroid stimulating antibodies (TSAb). About 2 months after t he first visit, TBII titers had risen to 48.9% and were persistently elevat ed for 5 months with high TBAb activity. The patient developed hypothyroidi sm with a maximum serum TSH level of 53.5 muU/ml. TBII and TBAb titers then gradually decreased, and the patient spontaneously recovered from hypothyr oidism. Eighteen months after the episode of subacute thyroiditis, he becam e hyperthyroid with elevated TSAb and negative TBAb values. Doppler ultraso nography showed increased blood flow in the thyroid, and RAIU at 24 h was 5 3%. He was treated :vith antithyroid drugs, and soon became euthyroid. This case indicates that subacute thyroiditis can induce thyroid autoimmunity, and that the character of TSH receptor antibodies (TSHRAb) in these patient s can change thereby modifying their thyroid function.