Here, we will review and comment on some recent work, involving both in vitro studies of human OA synovium and studies of OA pathology in animal models, which have strongly suggested that the inflamed synovium and activated syno- vial macrophages are important in promoting OA pa- thology. In particular, we will provide an overview of the role of synovial macrophages in promoting inflamma- tory and destructive responses in OA and the potential role of therapeutic strategies directed against macro- phages or macrophage-produced cytokines as remission- inducing agents in this disease.
Although it remains most likely that the fundamental difference between OA and RA is found at the level of cartilage and bone rather than in the synovium, the above findings would certainly stimu- late interest from academia and industry to investigate intracellular signaling and cytokine biology in OA syno- vium, in the search for potential therapeutic targets.
