Rheumatoid arthritis (RA) presents an extremely complex disease which is manifested in a number of autoimmune phenomena. Susceptibility genes (DR-β) and environmental factors play an important role as initiating agents. The early stage of the disease involves activation of the immune system via TCR complex. Stimulated T and B lymphocytes express upregulation of genes, followed by high cytokine production and intensive signal transduction. The same mechanism operates in other cells (macrophages, fibroblasts, endothelial cells).
In consequence regulatory abnormalities present some kind of “biological unformed state”. The therapy is directed towards pleiotropic (modification) or selective (target) methods. In the former (pre-biological treatment) MTX alone or in combination with other modifiers and low doses of prednisone are in general use. In case of unresponsiveness anti-TNF-α; or other biologicals are recommended.