COMP (Cartilage Oligomeric Matrix Protein)

Cartilage Oligomeric Matrix Protein (COMP) is a non-collagen protein in the matrix of articular cartilage (1). COMP has a molecular mass of 434 kDa consisting of five identical disulfide linked subunits. It is most abundant in cartilage, but has been detected in tendons, meniscus and synovial membrane. The function of COMP seems to be to stabilize the collagen network. When cartilage is broken down by a disease process, fragments (matrix proteins), such as COMP, are release into the synovial fluid. The matrix proteins are later found in the circulation, and can be used to monitor the cartilage deterioration in rheumatoid arthritis  and osteoarthritis.

The COMP assay is a solid-phase ELISA designed to measure human Cartilage Oligomeric Matrix Protein in cell supernates, cell lysates, serum or plasma. It employs the quantitative sandwich enzyme immunoassay principle.