The IMMULITE® 2000/2000 XPi TSI assay is the first automated and quantitative TSI assay available today. TSH receptor antibody (TRAb) assays detect both thyroid blocking and stimulating antibodies. However, blocking antibodies inhibit TSH stimulation of thyroid cells and lead to hypothyroidism. The IMMULITE 2000/2000 XPi TSI assay detects thyroid stimulating antibodies, the specific cause of GD pathology, with a clinical sensitivity and specificity of 98.6% and 98.5% respectively. With a 65-minute total assay time and ready-to-use, stable reagents, the use of this assay can make the differential diagnosis of GD faster and easier, allowing patients to be diagnosed and treated sooner.
TSI measurements are also used to monitor the response to GD therapy and prediction of remission or relapse, confirming Graves’ ophthalmopathy, and for predicting neonatal thyroid hyperthyroidism.1,2 Incorporating the TSI assay into existing diagnostic algorithms has been shown to reduce overall direct costs of GD diagnosis by up to 43%, with the net cost of avoiding misdiagnosis reduced by up to 85%.3