Cytokines in RA
Cytokines in rheumatoid arthritis
During the disease process, the role of the lymphocytes expands. Different cells respond upon stimulation by cytokines and a complex process of cell interactions, angiogenesis and bone destruction begins.
The lining of the synovium contains synoviocytes of type A and B. Type A shows similarity with macrophages. Synoviocyte B cells release the cytokines interleukin-8 (IL-8), IL-6, prostaglandins and metalloproteinases. IL-8 attracts lymphocytes in the capillaries in order to invade the sublining of the synovium. The metalloproteinases and prostaglandins are responsible for the destruction of cartilage and bone. The macrophages in the inflammatory tissue produce important mediators for all other cells involved.
Besides the inflammation, angiogenesis is an important process in rheumatoid arthritis. The newly formed capillaries provide oxygen and nutrients for the hypertrophic synovium and allow many lymphocytes to invade the tissue.
Inflammatory cytokines include all of the following EXCEPT