FIGURE 3.

Serum D-COMP but not total COMP concentrations declined following replacement of OA joints. Sera were obtained before and 6 months after joint arthroplasty in the BAJA cohort. Total serum COMP, measured by sandwich ELISA, and serum D-COMP, measured by competition ELISA, were determined pre- and 6 months post-joint replacement for n = 14 patents (nine knee and five hip replacements). mAb 6-1A12 was used for D-COMP competition ELISA; for total COMP sandwich ELISA mAbs 16-F12 captured and biotinylated 17-C10 for detection. Significant differences were determined using the paired nonparametric Wilcoxon signed rank test. Total COMP was unchanged after joint replacement (a), and D-COMP declined significantly (p = 0.017) following joint replacement (b).