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 ≤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.
|Original language||English (US)|
|Number of pages||3|
|State||Published - Dec 1 1985|
ASJC Scopus subject areas
- Clinical Biochemistry
- Biochemistry, medical