RESEARCH ARTICLE The active form of MMP-3

Full list of author information is available at the end of the articleBackground Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease, which primarily affects the spine and sacroiliac joints [1]. Rheumatoid arthritis (RA) is another chronic autoimmune disease with progressive synovial joint destruction. Increased turnover of extracellular matrix (ECM) proteins has been found in both AS and RA, and the MMPs are known to be important proteases respon-sible for ECM protein degradation [2]. Previous studies have indicated MMP-3 as a pathological mediator in AS, as well as RA [3,4]. The pathology of RA includes different cells of the joint such as chondrocytes, T cells, fibroblast-like synovio-cytes and macrophages, features which also are seen in AS. Among them, fibroblast-like synoviocytes are though