RESUMEN
Considering the role of maternal thyroid stimulating hormone [TSH] receptor blocking antibody [TRAb] in the etiology of congenital hypothyroidism [CH], this study aimed to determine TRAb among patients with CH in Isfahan, Iran. In this case-control study, patients with CH and their mothers were compared with a group of healthy neonates and their mothers. Venous blood samples were obtained for measurement of TRAb using enzyme-linked immunosorbent assay [ELISA] method among mothers and their neonates. TSH of mothers was also determined. The case group consisted of 65 patients with CH and their mothers; controls were 148 healthy neonates and their mothers. The prevalence of positive TRAb in patients with CH and their mothers was higher than in the control group [81.5% vs. 1.3% in mothers and 80% vs. 0% in neonates, respectively, P<0.05]. The relationship between the TRAb and occurrence of CH was significant [P<0.05], whereas the corresponding figure was not significant for TRAb and the level of maternal and neonatal TSH in case and control groups [P>0.05]. It seems that autoimmunity has an important role in the etiology of CH. Further studies are necessary to determine other autoantibodies in CH patients