TSH Receptor Antibody ELISA Kit (TRAb)

INTENDED USE

Human TSH receptor antibody ELISA kit is a reliable quantitative procedure for measuring TSH receptor autoantibodies (TRAb) in human serum. The minimum sensitivity limit of this assay is 0.55 U/L.

BACKGROUND

TSH receptor auotoantibodies (TSH receptor antibody, TRAb) are found to be predominantly located on the surfaces of thyroid epithelial cells, these are essentially autoantibodies that are directed against TSH receptors. They are particularly useful in helping to distinguish between Graves’ disease and postpartum thyroiditis. In many cases they can also be used to determine the likely risk of neonatal/foetal thyrotoxicosis.

During pregnancy TRAb are able cross the placenta and in many instances affect the foetal thyroid. A positive test can be used to alert the obstetrician of potential risks associated to the baby during the neonatal period, such as thyroid dysfunction in the offspring.

The measurement of maternal TRAb between gestation periods of 20 to 24 weeks is found to be an important tool in the prediction of the likelihood of neonatal Graves’ disease. Furthermore, the presence of maternal TRAb can result in stimulating the TSH receptor, also present are inhibitory/blocking immunoglobulins which can result in transient hypothyroidism for the infant.

CONTENT

All reagents supplied with need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• Coated Microwells 12 break-apart strips of 8 wells (96 in total): Bound with anti-TRAb antibody.
• Start Buffer.
• Calibrators 1-4: Concentration 1, 2, 8, 40 u/L (units are NIBSC 08/204).
• Control (Negative) And Control (Postive).
• TSH-Biotin Conjugate.
• Reconstitution Buffer for human TSH-biotin.
• Streptavidin Peroxidase (SA-POD)(20x Concentrated).
• Diluent for SA-POD.
• TMB Peroxidase Substrate.
• Concentrated Wash Solution (10x Concentrated).
• Stop Solution.

SENSITIVITY

The minimum sensitivity detection limit of TSH receptor antibody (human TRAb) using the current TRAb ELISA kit is 0.55 U/L. The dynamic range for this assay is 1.0 – 40.0 U/L (WHO).

ASSAY CHARACTERISTICS

– Assay Cut Off: Negative (<1 u/L), Positive (>1.5 u/L), Equivocal (1.1 – 1.5 u/L).
– Clinical Specificity: 99% were identified as being negative when sera from healty blood donors was assayed.
– Function Sensitivity: A plot of inter assay CV against u/L indicates a 20% CV occurring at 0.60 u/L.
– Intra-Assay Variation: 10.9 – 12.9%
– Inter-Assay Variation: 2.2 – 7.1%
– Lower Detection Level: 0.21 u/L
– Interfering Substances: None

REFERENCES

1. Autoimmune response to the thyroid in humans: thyroid peroxidase–the common autoantigenic denominator. Int. Rev. Immunol. (2000). 19 (6): 587–618. McLachlan SM, Rapoport B.
2. Anti-TSH receptor antibodies in clinical practice. Endocrinology and metabolism clinics of North America. (2000) 29 (2): 339–55. Orgiazzi, J.
3. The human anti-thyroid peroxidase autoantibody repertoire in Graves’ and Hashimoto’s autoimmune thyroid diseases. Immunogenetics. (2002) 54 (3): 141–57. Chardès T, et al.

ADDITIONAL INFORMATION

• Full Name: TSH Receptor Antibody ELISA Kit (TRAb)
• Reactivity: Human
• Sample Type: Serum
• Sensitivity: 0.55 U/L

OTHER RELATED ELISA KITS

• TSH ELISA Kit
• Thyroglobulin Ab ELISA Kit
• Thyroglobulin (hTG) ELISA Kit