Monoclonal antibodies specific for 18-hydroxycortisol and their use in an enzyme immunoassay for human urinary 18-hydroxycortisol for diagnosis of primary aldosteronism
✍ Scribed by Hiroaki Kohno; Seiji Sato; Hitoshi Chiba; Kunihiko Kobayashi; Shigeo Ikegawa; Takao Kurosawa; Masahiko Tohma
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 642 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0009-9120
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✦ Synopsis
We report the development of a monoclonal antibody-based enzyme immunoassay (EIA) specific for human urinary 18hydroxycortisol, a biological marker of primary aldosteronism. Hybrid cell lines (hybridomas) were isolated after fusion between myeloma cells and spleen cells prepared from mice immunized with 18-hydroxycortisol conjugate. A competitive EIA suitable for the measurement of urinary 18-hydroxycortisol was developed using the mouse monoclonal antibody, KTM-41, which showed no practical cross-reaction with related endogeneous steroids and synthetic steroids. This EIA meets all the requirements of routine clinical assay in terms of sensitivity (detection limit: 20 nmol/L), reproducibility (total CV: S-15%), accuracy (recovery: 88-115%) simplicity and rapidity (~3 h). Urinary 18-hydroxycortisol measured by the present assay was 153 & 119 nmol/L (mean + SD, range, 28485) and 1787 rt 1180 (range, 810-4284) in normal subjects (n = 20) and in patients with primary aldosteronism (n = 7) respectively. Clinical validation of the assay was confirmed by an appropriate decrease in urinary 18-hydroxycortisol level in patients with primary aldosteronism subsequent to adrenalectomy: 171 * 141 nmol/L (range, 41+88).