Receptor binding assay for detecting auto-antibodies to thyroid stimulating hormone receptor

摘要

Receptor-binding assay for detecting autoantibodies (AAb) to thyroid stimulating hormone receptor (TSHR) comprises reacting, simultaneously or sequentially, the sample with a TSRH preparation (A) and /- 1 of: (i) competitor, and (ii) agent for separation of TSHR and any material bound to it from the liquid phase, with one of (i) and (ii) being marked or selectively markable. The complex formed by binding of AAb and/or competitor to (A) is separated and the amount of label in it used to detect the presence and/or amount of AAb. (A) is a recombinant TSH-fusion receptor (I) which, compared with functional TSHR, is extended by a peptide (II) that: (i) is marked or selectively markable, and/or (ii) is immobilised or immobilisable, by binding to a selective binding partner, without significant effect on the function of TSHR in the assay. Also claimed are: (1) (I); (2) vaccinia virus having inserted in its genome, at the site of the thymidine kinase gene, a DNA sequence encoding (I), and (3) a similar but more general receptor binding assay for a hormone or autoantibody (able under physiological conditions to interact with cell-membrane localised G-protein coupled glycoprotein receptor to induce or block hormone activity) in which the receptor preparation used is a recombinant fusion extended by (II).