RESUMO
Tumor necrosis factor alpha(TNF-?) is one of the key proinflammatory factors in driving and attending chronic inflammatory process in rheumatoid arthritis(RA).TNF-? acts on different kinds of cell in synovial membrane,such as synoviocytes,macrophages,osteoclasts and chondrocytes,which can produce metalloproteinase,collagenase,stromelysin and so on,further induce pannus formation,joint inflammation,bone erosion and cartilage degradation. The TNF inhibitors have been proved by a lot of clinical trials to be an important new group of agents that significantly improve symptoms and signs,induce remission,reduce objectively measured damage in chronic inflammatory conditions,such as RA.There are three kinds of TNF inhibitors: Etanercept,Infliximab and Adalimumab.Etanercept is a fusion protein of human IgG and two p75 TNF receptors.Infliximab is an IgG1 monoclonal antibody(a chimera of human constant and mouse variable regions).Adalimumab is a humanized IgG1 monoclonal antibody with fully human constant and variable regions.The side effects include injection site infusion reactions,infection,lymphoproliferative disease,demyelinating disease,and SLE-like syndromes.