The Role of Thyrotrophin Receptor Antibody Assays in Graves’ Disease
Table 1
A comparison of TBII and biological assays.
TBII assays
Biological assays
Advantages
Freely available commercially
Differentiate between stimulating and blocking activities of TRAb
Relatively cheap
Easy to perform
Sensitive 2nd-3rd generation assays available
Disadvantages
Do not differentiate between stimulating and blocking activities of TRAb
Most are technically complex and time consuming
Lack absolute correlation with clinical phenotype
Relatively expensive
No correlation with severity of illness
Lack predictive value for GD outcome
TBII are easy to perform, cheap and are highly sensitive. They remain the preferred assay method of choice in clinical practice. Bioassays have the ability to differentiate between stimulating and blocking TRAb, but the utility of this property in day-to-day clinical practice is unclear. Furthermore, they require greater technical expertise to perform and currently are more expensive.