Endocrine Abstracts

We report a falsely elevated blood spot thyrotrophin (TSH) concentration caused by a TSH-IgG complex. A routine blood spot screen returned a whole blood TSH of 213 mU/l from a one week-old neonate using the Wallac DELFIA method. Measurement in serum confirmed elevated TSH (826 mU/l, Roche Elecsys assay) but free thyroxine (17.2 pmol/l) was normal. The baby’s mother was clinically euthyroid but also showed discordant high serum TSH (287 mU/l) with normal free thyroxine (13...