[Thyroid stimulators other than TSH. Classification. Immunoglobulins of Basedow's disease: history, methodology,...

Two families of thyroid stimulators can be described besides TSH: a) hormonal factors, b) Graves' IgGs. Hormonal factors include: biogenic amines (catecholamines, histamine, serotonine), prostaglandins E and LH and hCG. The stimulating effect of the latters is expressed only at very high concentration. Thyroid stimulating effect of GH, insulin, cortisol, NGF and FGF is probably ancillary. Thyroid stimulating IgG were first represented by the LATS. Graves' IgGs are currently detected by their interaction with human thyroid tissue in vitro: one either detects thyroid stimulation (cAMP or hormone production) or binding inhibition of LATS or TSH. These various activities are denominated: thyroid-stimulating IgG (TSI) or antibodies (TSAb), or LATS-Protector (LATS-P) or thyrotropin binding inhibitory (TBIA). TBIA IgGs are not necessarily TSI. Thyroid growth stimulatory IgGs (TGI) have also been described as well as TSAb or TGI blocking IgG, that also block TSH effects. Graves' IgGs probably include a mosaic of specificities directed against different parts of thyroid cell surface antigens constituting, or near, the TSH receptor complex. TSI represent only one or a few types of these specificities.