Identification of hyperthyroid patients by means of a sensitive assay for thyrotropin.
We evaluated a new assay (TSH3 MAIAclone) for thyrotropin (TSH) with improved sensitivity, testing a series of hospital inpatients with increased free thyroxin indices (thyroxin concentration X triiodothyronine uptake on resin). This assay involves use of three monoclonal antibodies and an antibody-magnetic particle conjugate that rapidly and completely separates bound and free tracer in a magnetic field. The assay turnaround time is 3 h. By the TSH3-MAIAclone assay, 65% of these patients with an increased free thyroxin index were identified on the basis of a TSH value less than or equal to 0.50 milli-int. unit/L. In contrast, another commercially available assay for TSH detected suppressed TSH concentrations in less than 5% of these patients. We conclude that the TSH3 MAIAclone assay markedly improves our ability to discriminate hyperthyroidism from euthyroidism.
D000911:Antibodies, Monoclonal; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000175:diagnosis*; D007118:Immunoassay / Q000379:methods; D008297:Male; D011933:Reagent Kits, Diagnostic; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood*
D000911:Antibodies, Monoclonal; D011933:Reagent Kits, Diagnostic; D013972:Thyrotropin