Abstract
A sensitive assay for thyroglobulin autoantibodies (Tg-ab) is described. The assay is based on prolonged incubation of [125I]Tg with serum followed by precipitation of antibody bound [125I]Tg by polyethylene glycol (PEG). The PEG concentration was chosen to give a low precipitation of free [125I]Tg while effectively precipitating Tg-ab-bound [125I]Tg. The lowest reference employed contained 19.5 MRC U/l Tg-ab. This was always different from an incubate without Tg-ab. Tg standard added to samples interfered in the assay giving spuriously low Tg-ab values as in other Tg-ab assays. Tg-ab added to samples was recovered quantitatively. The interassay coefficient of variation was 19.8% and the intra-assay coefficient of variation 11.3%. Only eight of 66 serum samples with various amounts of Tg-ab, measured with the new assay, had levels of Tg-ab detectable by the passive haemagglutination test.
| Original language | English |
|---|---|
| Journal | Scandinavian Journal of Clinical & Laboratory Investigation |
| Volume | 48 |
| Issue number | 2 |
| Pages (from-to) | 137-40 |
| Number of pages | 4 |
| ISSN | 0036-5513 |
| Publication status | Published - Apr 1988 |
| Externally published | Yes |
Keywords
- Autoantibodies
- Chemical Precipitation
- Hemagglutination Tests
- Humans
- Immunoassay
- Polyethylene Glycols
- Thyroglobulin
- Thyroiditis, Autoimmune