Development of a monoclonal antibody to urinary degradation products from the C-terminal telopeptide α1 chain of type I collagen. Application in an enzyme immunoassay and comparison to CrossLaps™ ELISA

A monoclonal antibody MAbA7 was raised against a synthetic peptide having a sequence (EKAHDGGR) specific for a part of the C-telopeptide α1 chain of type I collagen. MAbA7 was labelled with horseradish peroxide and used in a competitive one-step enzyme-linked immunosorbent assay (ELISA) for measurement of urinary type I collagen degradation products. The assay was technically evaluated and preliminary clinical data are presented. The measuring range was 200–7000 µg 1−1 with a detection limit of 25 µg 1−1. Within-run and total CVs were 5.5 and 8.0%, respectively. Analytical recovery averaged 96.6%±M5.3 (mean±1SD). Values obtained in the ELISA were highly correlated (r=0.93) to values obtained by a commercially available assay (CrossLaps™ ELISA) known to measure urinary degradation products derived from the C-telopeptide of type I collagen reflecting the rate of bone resorption. Investigation of the urinary fragments responsible for the immunological response in the two assays revealed, however, that they a...