Competitive idiotype--anti-idiotype immunoassay for adenosine deaminase binding protein in urine

This competitive immunoassay, based on inhibition by antigen of the idiotype-anti-idiotype interaction, detects adenosine deaminase binding protein (ABP), and involves use of monoclonal anti-idiotype antibodies prepared to a monoclonal antibody specific for ABP. The conditions for this new type of competitive immunoassay are investigated. This competitive immunoassay is as sensitive and reproducible as an earlier described "sandwich"-type immunoassay for ABP (Clin Chem 31: 679-683, 1985). Evaluation of urine samples from normal subjects and from patients showed increased concentrations of ABP in patients with renal disease.