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Measurement of TSH receptor blocking immunoglobulins using 3 H‐adenine incorporation into FRTL‐5 and JPO9 cells: use in a child with neonatal hypothyroidism
Author(s) -
Michelangell Vaido P.,
Poon Cathy W.,
Arnus Emllia E.,
Frauman Albert G.,
Connelly John,
Colman Peter G.
Publication year - 1995
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1995.tb02596.x
Subject(s) - endocrinology , medicine , antibody , thyroid , congenital hypothyroidism , thyroid peroxidase , thyrotropin receptor , blocking antibody , receptor , graves' disease , immunology
Summary OBJECTIVE The aim of this study was to develop an assay for the measurement of thyroid blocking antibodies (TBAb), based on the ability of patient serum to inhibit TSH stimulated 3 H‐cAMP production following incubation of FRTL‐5 or JPOS cells with 3 H‐adenine. The assay was then used to evaluate a child born with neonatal hypothyroidism. DESIGN The levels of TBAb, TSAb (thyroid stimulating antibodies), TBII (TSH binding Inhibitory antibodies), and the thyroid antibodies anti‐thyroid peroxidase and thymoglobulin antibodies were measured in both mother and child over a 6‐month post‐natal period. PATIENT The assay for TBAb was used to evaluate a child born with neonatal hypothyroidism whose mother had a history of hypothyroidism due to Haehimoto's thyrolditis. A 99m Tc pertechnetate scan showed no evidence of functioning thyroid tissue. At 20 months of age an ultrasound verified a normally positioned thyroid. RESULTS Initially, high levels of TBII and antithyroid antibodies were present in the serum of both mother and child. In both, the levels of TSAb were undetectable but there were significant levels of TBAb. The levels of TBAb decreased to control levels in the child within 2 months of birth but remained elevated in the mother's serum. CONCLUSIONS This case of neonatal hypothyroidism associated with the passage of thyroid blocking antibodies demonstrates the utility of this new assay in the differential diagnosis of neonatal hypothyroidism.