The typical symptoms and structural changes that characterize osteoarthritis (OA) are related to alterations in the matrix metabolism in affected joints. These metabolic changes are presumably associated with an altered release of (fragments of) matrix molecules from joint tissues such as cartilage, bone, and synovial tissue. As such, circulating matrix molecules in synovial fluid, blood, and/or urine that do represent important metabolic pathways in the pathogenesis of OA may function as biochemical markers for this process. Such biochemical markers may aid researchers and clinicians in diagnosing and staging OA and in giving a prognosis.
Especially markers of articular cartilage degradation have attracted much attention as potential biochemical markers for OA. Among them, collagen type II degradation markers and particularly CTX-II (C-terminal telopeptide of collagen type II) are generally considered to be the most successful markers. Another relatively successful marker is COMP (cartilage oligomeric matrix protein), a non-collagenous protein that can be derived from both cartilage and synovial tissue. An ever growing number of other potential biochemical markers is being studied, although most markers are studied in only a limited number of small studies.
Although steps have certainly been made in the biochemical marker field, to date no marker or combination of markers has shown sufficiently strong and consistent associations with relevant clinical and structural OA parameters to justify wide introduction in OA research and practice. This overview will describe challenges that will need to be covered before biochemical markers can be more widely introduced in OA research and practice.
Disclosure of Interest None declared