The Role of Mesenchymal Stem Cell Transplantation in Adjuvant Induced Arthritis in Rats: A Pilot Study

Abstract

R heumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that leads to chronic inflammation in the joints with subsequent cartilage destruction and bone erosion in addition to extra-articular manifestations leading to severe disability. It causes a great load on health services worldwide. Many efforts to discover new target therapies had achieved considerable success. The synovium is the central area of pathology in RA. Activation of both innate and adaptive immune systems leads to a specific mesenchymal tissue response with subsequent structural damage to cartilage and bone. Infiltration of the synovium with mononuclear cells, especially T cells and macrophages, vascular changes with synovial intimal lining hyperplasia are hallmarks of RA. Angiogenesis is a dynamic process which occurs early in the development of synovitis in RA. It is now generally accepted that angiogenesis is central to maintaining and promoting RA because of the need for blood vessels either to recruit leukocytes or to provide nutrients and oxygen to the starved expanding synovium. Although many pro-angiogenic factors have been identified (as hypoxia, growth factors, cytokines and chemokines), vascular endothelial growth factor (VEGF) has a central role in the angiogenic process. Bevacizumab (Avastin®) is a recombinant humanized monoclonal antibody that prevents binding of VEGF to receptors on vascular endothelial cells, leading to inhibition of angiogenesis.