title: Equivalent discrimination among states of thyroid function by immunochemiluminimetric and immunoradiometric determination of thyrotropin.
abstract: New immunochemiluminometric assays (ICMA) of thyrotropin (TSH) have been reported to facilitate the diagnosis of hyperthyroidism. To compare the accuracy of ICMA-TSH with that of a conventional immunoradiometric assay (IRMA-TSH), we examined 115 consecutive patients of a thyroid outpatient clinic. On the basis of complete thyroid-function testing, including thyroliberin tests, the untreated patients (n = 89) were subclinically hyperthyroid (n = 21), subclinically hypothyroid (n = 13), or euthyroid (n = 55). The receiver-operating characteristic (ROC) curve, used for comparing the TSH values obtained by these two methods, was shifted to the left for the IRMA-TSH. The area under the curve was greater for IRMA-TSH than for ICMA-TSH (0.984 vs 0.869, respectively), which suggests equal or better clinical performance of IRMA-TSH vs ICMA-TSH in discriminating between hyperthyroidism and euthyroidism. Both assays displayed similar clinical sensitivity/specificity for evaluating thyroid function in hypothyroid and treated patients. We conclude that the ICMA-TSH tested is not more accurate than an IRMA in distinguishing between hyperthyroidism and euthyroidism.
authors.affiliation: Department of Medicine III, University of Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Roden
authors.forename: P
authors.initials: P
authors.lastname: Nowotny
authors.forename: U
authors.initials: U
authors.lastname: Hollenstein
authors.forename: B
authors.initials: B
authors.lastname: Schneider
authors.forename: H
authors.initials: H
authors.lastname: Vierhapper
authors.forename: W
authors.initials: W
authors.lastname: Waldhäusl
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood*; D007037:Hypothyroidism / Q000097:blood*; D015592:Immunoradiometric Assay; D008875:Middle Aged; D012372:ROC Curve; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin