Essential role of neutrophils in initiation of arthritis

Excerpt

Although elevated numbers of neutrophils are present in the rheumatoid joint, their specific contribution to the onset of arthritis has not been determined. Neutrophils secrete a number of bioactive molecules, including destructive enzymes and proinflammatory cytokines. Also released are oxidative species such as nitric oxide (NO) and hydrogen peroxide that may lead to metalloproteinase activation or cartilage damage. During the acute onset of disease in animal models there is an immediate influx of these cells. As inflammation develops into a chronic condition, however, populations of infiltrating neutrophils are largely replaced by macrophages and lymphocytes. In the K/BxN transgenic mouse model of arthritis, affected mice spontaneously generate autoantibodies to a ubiquitous antigen, glucose-6-phosphate isomerase (GPI). Intraperitoneal transfer of serum or purified immunoglobulin from K/BxN mice will induce joint-specific inflammatory disease in recipient mice similar to that found in rheumatoid arthritis (RA). This K/BxN serum transfer model was used to evaluate the role of neutrophils in the onset of arthritis. …