Pregnancy-associated changes in the thyroid-stimulating antibody of Graves' disease and the relationship to neonatal hyperthyroidism.
Assays for the thyroid-stimulating antibody (TSAb) of Graves' disease were performed with serum obtained from 17 women with 20 pregnancies who either had or had had Graves' disease, or who had delivered a child with neonatal hyperthyroidism. Ten of the children, of eight women, were diagnosed as being hyperthyroid; all eight mothers had high concentrations of TSAb, as measured by adenylate cyclase stimulation. In the infants with neonatal hyperthyroidism, a minimum 500% increase in cAMP was found on assay of maternal immunoglobulin G, and no such high values were associated with a euthyroid infant. Blood samples for TSAb assay were available from 11 mothers on both the day of delivery and at least 1 other time in the pre- or postpartum period. In 7 mothers, the lowest value (negative in 4) was obtained coincident with delivery, and in the remaining 4, there was no pregnancy-associated change. Thus, a pattern, related to pregnancy, of a decline in TSAb concentration or a subsequent postpartum increase was observed in the majority of subjects. Apparently, neonatal hyperthyroidism due to transplacental passage of TSAb occurred only when this decline did not reduce the concentration to a low value.
D000906:Antibodies / Q000032:analysis* / Q000502:physiology; D005260:Female; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D006980:Hyperthyroidism / Q000276:immunology*; D018828:Immunoglobulins, Thyroid-Stimulating; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*
D000906:Antibodies; D018828:Immunoglobulins, Thyroid-Stimulating