Biomarker Portfolio

We developed a novel assay, PRO-C10, for measurement of chondrocyte hypertrophy and found its levels significantly elevated in OA patients with KL score of 2, and also in OA patients with above normal hsCRP levels. Concentration of PRO-C10 strongly correlated with levels of C2M, a marker of cartilage destruction. The data suggest that chondrocyte hypertrophy and subsequent collagen X fragmentation seem to be increased in a subset of patients with inflammatory OA.

A competitive ELISA, PRO-C10, applying a well-characterized monoclonal antibody was developed as a biomarker of chondrocyte hypertrophy through measurement of type X collagen (ColX). The levels of PRO-C10, C2M (matrix metalloproteinase-derived fragments of type II collagen) and hsCRP (high sensitive C-reactive protein) were quantified by ELISAs in serum of 271 OA patients stratified by Kellgren-Lawrence (KL) score 0-4. Associations between serum levels of the three biomarkers (log transformed) were analyzed by Pearson's correlation and differences in PRO-C10 levels between patients with high and low levels of inflammation measured by hsCRP were analyzed by ANOVA.

Age and BMI adjustment didn't change the results. Immuno-staining revealed that ColX was predominately located around the hypertrophic chondrocytes and the clustered chondrocytes indicating that PRO-C10measures may be linked to cartilage hypertrophic changes.

• Chondrocyte activity is increased in psoriatic arthritis and axial spondyloarthritis
• Potential diagnostic value of a type X collagen neo-epitope biomarker for knee osteoarthritis
• Type X collagen levels are elevated in serum from human osteoarthritis patients and associated with biomarkers of cartilage degradation and inflammation