Congenital Hypothyroidism due to a Low Level of Maternal Thyrotropin Receptor-Blocking Antibodies. Issue 2 (5th April 2021)

• Record Type: Journal Article
• Authors: Castellnou, Solène; Bretones, Patricia; Abeillon, Juliette; Moret, Myriam; Perrin, Pauline; Chikh, Karim; Raverot, Véronique
• Is Part Of: European thyroid journal. Volume 10:Issue 2(2021)
• Page Start: 174
• Page End: 178
• Publication Date: 2021-04-05
• Subjects: Congenital hypothyroidism -- Thyrotropin receptor-blocking antibodies -- TRAb -- TBAb -- TSHR Ab; Thyroid gland -- Diseases -- Periodicals; Thyroid Diseases -- Periodicals; 612.44
• DOI: 10.1159/000509015
• Languages: English
• ISSNs: 2235-0640

Abstract

Abstract : Introduction: Maternal TSH receptor antibodies (TRAbs) can cross the placenta and affect fetal and neonatal thyroid function. Maternal TSH receptor-blocking antibodies (TBAbs) are a rare cause of congenital hypothyroidism. Case Report: Following the discovery of a highly elevated TSH on her neonatal screening test, a 10-day-old girl with no familial history of thyroid disorder was referred to the pediatric endocrinology unit. Hypothyroidism was confirmed with a highly elevated TSH (817 mIU/L, reference range 0.4–3.1) and very low levels of FT4 (1.8 pmol/L, reference range 12–22). Anti-TPO antibodies were at 81 IU/mL (reference range <34), TRAbs at 1.7 IU/L (reference range <1.75), and thyroglobulin at 9.4 µg/L (reference range 3.5–77). The thyroid appeared normal on ultrasonography, and no radioiodine uptake was seen on the scintigraphy after the perchlorate discharge test. Concomitantly, a severe maternal hypothyroidism was discovered (TSH 224 mIU/L). The maternal ultrasound appeared normal, anti-TPO antibodies were moderately elevated, and TRAbs were at 3.2 IU/L. TBAbs activity was measured in the mother and her daughter, and a very high and similar blocking activity was observed in both patients (TBAbs 89%, reference range <10%). L-thyroxine treatment was introduced in the newborn and was successfully discontinued at 6.5 months of age, as the TBAbs activity decreased. Conclusion: We report herein a case of transient congenital hypothyroidism with a normal neonatal TRAbs level. In case of maternal TBAbs, similar activity of maternal TBAbs must be expected in the neonate, independently of the neonatal level of TRAbs.