THYROID IODINE CONTENT AND SERUM THYROID-HORMONE LEVELS IN AUTOIMMUNE-THYROIDITIS - EFFECT OF IODIDE SUPPLEMENTATION

  • 1 January 1985
    • journal article
    • research article
    • Vol. 26  (2) , 133-139
Abstract
The relationship between thryoid iodine content (TIC) measured by x-ray fluorescence and serum TSH, T4 [thryoxine] and T3 levels was investigated under iodide supplementation (0.5 mg/day for 1-9 mo.). In 5 euthyroid control patients, whose TIC ranged from 2.5- 14 mg, the TIC increased from 1.5 to 4 mg after 4 wk of treatment and had a tendency to plateau when the treatment was pursued. No significant changes in serum T4, T3 and TSH levels have been observed in these control subjects. Patients (14) with autoimmune thyroiditis with low TIC (0-5 mg) were also studied. In six patients, the TIC increased significantly (3-10 mg over initial value after 3-7 m. of treatment). In parallel, there was a significant increase in serum T4 levels (35-150% over initial value) while T3 levels were modified in only 2 patients. In 5 patients serum TSH level decreased and was 2-7-fold lower than before treatment whatever was its initial value; however, the spectrum of changes varied among patients from slight increase to a complete normalization in hormonosynthesis. In the 8 other patients, iodide supplementation aggravated the thyroid disorders during the 1st months of treatment. The thyroid hormone blood levels dropped significantly in 6 patients (percent decrease below initial value: 20-100%) and was unchanged in the 2 others. An increase in the TSH blood level (.times. 2-6) was observed in all patients except one. Concomitantly, the iodine stores were progressively depleted in 3 patients, unchanged in 3 and increased in 2. When iodide treatment was pursued, an escape from this organification block was observed in 2 patients.