Radioimmunoassay of type I collagen that mainly detects degradation products in serum: application to patients with liver diseases

Abstract

This radioimmunoassay for type I collagen mainly detects degradation products of the molecule in human serum samples. Type I collagen antigenicity in serum can be separated into two peaks by gel-filtration chromatography. The larger form represents collagen molecules (as shown by immunoblotting experiments), and (or) type I collagen with aminoterminal propeptide or intact procollagen molecules. The smaller form, the exact nature of which is not known, is quantitatively the principal antigenic form and is derived from degradation of type I collagen. The concentration of type I collagen in serum is increased mainly in cirrhotic patients, with or without active liver disease, but also somewhat in alcoholic patients without cirrhosis.

Collagen-Related Markers of Bone Turnover Reflect the Severity of Liver Fibrosis in Patients with Primary Biliary Cirrhosis

“…Although, this hypothesis cannot be excluded, it seems unlikely, since other collagen‐related markers cleared by the kidney are also increased in PBC. Previous studies have found that PICP levels are elevated in patients with liver disease (23,24) …”

Monitoring of extracellular matrix metabolism and cross‐linking in tissue, serum and urine of patients with chromoblastomycosis, a chronic skin fibrosis

“…Two radioimmunoassays, developed in the laboratory, were used for type I (CI) and type III (CIII) collagens. The CI assay detected mostly degradation products of type I collagen [20], whereas the CIII assay accounted for type III collagen synthesis [21]. The upper values for the CI and CIII assays were respectively 200 and 40 mg L ¹1 in healthy adults.…”

Measuring collagen degradation

“…It also seems to detect increased osteolysis in myeloma and in bone metastases. A third radioimmunoassay for the main triple-helical region of Type I collagen molecule detects antigens of small molecular size, obvious breakdown products, in human serum [8]. Their concentration increases in liver cirrhosis; they have not been studied in bone disease.…”