We evaluated the technical robustness of the new commercial TBII assay using human recombinant TSH-R, and describe its use for the clinician in the routine laboratory. The human recombinant TSH-R assay (DYNOtest TRAK human) was compared to a conventional TBII assay (TSH-REZAK). Specificity was adjusted at 99.1% for both assays by ROC plot analysis including 113 healthy individuals. Sensitivity in 115 patients with active Graves' Disease (GD) was 98.2% for the DYNOtest TRAK human compared to 68.4% for the TSH-REZAK (p<0.0001). Comparison of the ROC-calculated cut off confirmed the recommended cut-off for the DYNOtest TRAK human, since 11% inhibition of tracer equals 1 IU/L, which is recommended as the grey zone. At the recommended cut-off (2 IU/L, 22% inhibition), the sensitivity is still 93.9% with 100% specificity. The ROC plot-derived cut-off of the TSH-REZAK (4.4%, 2 to 10 U/L) is below the grey zone of 10-15 U/L. At the recommended cut off of 15 U/L, the sensitivity is 43.0% with a specificity of 100%. Both assays showed a good correlation (r = 0.82, p < 0.0001); however, assay comparison revealed a constant bias in favour of the DYNOtest TRAK human. Applying the ROC plot-derived cut-off of 11 % inhibition (1 IU/L) for the DYNOtest TRAK human, we found 15 of 50 patients with autoimmune thyroiditis (AIT) and 6 of 23 patients with goitre (all < 1.5 IU/L). These patients would have been missed using the recommended 2 IU/L. The difference in sensitivity between the DYNOtest TRAK human and the TSH-REZAK was highly significant in the GD group, but not in other groups, indicating that the DYNOtest TRAK human has a higher sensitivity for GD without compromising specificity. In summary, the proposed high sensitivity of the new TBII assay using human recombinant TSH-R could be confirmed with the commercial product. This method offers a clear advantage over conventional TBII assays to confirm or exclude the diagnosis of GD. The recommended cut-off is very stringent, and until we have more information on the clinical relevance of low-level TBII between 1 and 1.5 IU/L, those patients should be monitored for the development of autoimmune thyroid disease.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.