Kronus®, Boise Idaho, has received FDA 510(k) clearance for its improved, non-isotopic ELISA test kit for the detection and measurement of antibodies to the TSH receptor (TRAb). 

The assay uses the proprietary thyroid-stimulating human monoclonal autoantibody M22 (directly coupled to the peroxidase reagent), which increases sensitivity while reducing assay time. 

Antibodies to TRAb are detectable in approximately 85% of untreated Graves’ disease patients. Their presence indicates the patient’s thyrotoxicosis is of autoimmune etiology rather than due to toxic nodular goiter.