Thyrotropin Receptor Antibody, Serum

Thyrotropin Receptor Antibody, Serum

Number
	010314
CPT
	83519
Related Information
	Thyroid-Stimulating Immunoglobulin (TSI)
Synonyms
	LATS ; Long-Acting Thyroid Stimulator ; TBII ; Thyrotropin-Binding Inhibitory Immunoglobulin ; TRAb ; TSH Receptor Antibody ; TSH Receptor Binding Inhibitory Immunoglobulin
Specimen
	Serum
Volume
	1 mL
Minimum Volume
	0.4 mL (Note: This volume does not allow for repeat testing.)
Container
	Red-top tube or gel-barrier tube
Collection
	If tube other than a gel-barrier tube is used, transfer separated serum to a plastic transport tube.
Storage Instructions
	Refrigerate at 2°C to 8°C.
Patient Preparation
	No radioisotopes administered 24 hours prior to venipuncture
Causes for Rejection
	Recently administered isotopes; plasma specimen
Reference Interval
	TSH binding inhibition index: negative: <1.0 units/L, borderline: 1.0-1.5 units/L, positive: >1.5 units/L
Use
	Diagnosis of hyperthyroidism and Graves' disease
Methodology
	Enzyme-linked immunosorbent assay (ELISA)
Additional Information
	Thyrotropin-receptor antibody is an autoantibody to the thyroid cell receptor for thyroid-stimulating hormone. It can be demonstrated in 90% of patients with Graves' disease, and is the cause of the hyperthyroidism of that condition. The characterization of TRA resolved much confusion about long-acting thyroid stimulator (LATS) and LATS protector, which are both, in fact, thyroid-stimulating autoantibodies which simply behaved differently in animal test systems. These antibodies are present in 50% of euthyroid Graves' disease as well as hyperthyroid patients. They play a major role in the pathogenesis of Graves' disease. Detection of these antibodies is useful in prediction of neonatal hyperthyroidism and prediction of relapse of hyperthyroidism.
References
	Colvin RB, Bhan AK, and McCluskey RT, eds, Diagnostic Immunopathology, New York, NY: Raven Press, 1988. Gupta MK, “Recent Advances in Laboratory Tests for Autoantibodies to Thyrotropin Receptor Protein in Graves' Disease,” Clin Lab Med, 1988, 8(2):303-23 (review). Gupta MK, “Thyrotropin Receptor Antibodies: Advances and Importance of Detection Techniques in Thyroid Disease,” Clin Biochem, 1992, 25(3):193-9. McKenzie JM and Zakarija M, “Clinical Review 3: The Clinical Use of Thyrotropin Receptor Antibody,” J Clin Endocrinol Metab, 1989, 69(6):1093-6. Morris JC III, Hay ID, Nelson RE, et al, “Clinical Utility of Thyrotropin-Receptor Antibody Assays: Comparison of Radioreceptor and Bioassay Methods,” Mayo Clin Proc, 1988, 63(7):707-17. Nakamura RM and Binder WL, “Current Concepts and Diagnostic Evaluation of Autoimmune Disease,” Arch Pathol Lab Med, 1988, 112(9):869-77 (review).