Journal of Clinical Endocrinology & Metabolism, Vol 81, 641-645, Copyright © 1996 by Endocrine Society

ARTICLES

Relationship of antibodies to thyrotropin receptors and to thyroid ultrasonographic volume in euthyroid and hypothyroid patients with autoimmune thyroiditis

M Rieu, C Portos, B Lissak, S Laplanche, B Sambor, JL Berrod and JP Fombeur
Department of Endocrinology, Saint-Michel Hospital, Paris, France.

It has been reported in hypothyroid patients with Hashimoto's thyroiditis and in patients with primary myxoedema that antibodies (Ab) to the TSH-receptor (R), which inhibit the thyroid gland, decrease both thyroid hormonogenesis and cell growth in vitro. We investigated, in 169 newly diagnosed patients with euthyroid (n = 83) or hypothyroid (n = 86) autoimmune thyroiditis, the relationship between thyroid autoimmunity expression and thyroid ultrasonographic volume or thyroid hormonal status. In patients positive for TSH-receptor (R) antibodies (Ab), negative correlations (P < 0.01) were found between TSH-R Ab levels and free T4 (FT4) values in a euthyroid (r = -0.63), as well as in a hypothyroid (r = -0.54) state, and between TSH-R Ab and total thyroid volume (TTV) values in an euthyroid (r = -0.62) as well as in a hypothyroid (r = -0.53) state. In contrast, no positive correlations were found between TSH levels and FT4 values or TTV levels in patients positive as well as negative for TSH-R Ab in an euthyroid or in a hypothyroid state. These data demonstrate in vivo, that, in contrast to TSH, TSH-R Abs are related to both thyroid hormonal production and volume in euthyroid or hypothyroid patients with autoimmune thyroiditis.