Joint destruction process, synovial hyperplasia, angiogenesis, edema, lymphocyte infiltration, treatments. In the upper left is a joint seen in section with articular destruction with abnormal secretion of synovial fluid, synovial hyperplasia with lymphocyte infiltration and angiogenesis. Below, zoom on the synovium and the process of synovial cell proliferation, the production of proteases and free radicals induced by cytokines TNFa and lymphokines IL1 causing joint destruction.