Pathophysiology and pharmacology of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is the classical example of an immune complex (IC) associated systemic autoimmune disease. Although an important part of SLE etiopathogenesis has yet to be discovered, it is generally accepted that genetic factors, sex hormones, alternations in T- and B-lymphocyte activity and defects in RES-function contribute to the development of SLE. In an SLE patient, symptoms and severity of the disease are linked to the pattern of autoantibodies expressed, referring to some pathophysiological importance of antibodies found in SLE. In addition, the interindividually variable expression of antibodies to ds-DNA, Ro or anticardiolipin, for example, permit a subtyping of SLE and indicate SLE as collective concept of heterogeneous systemic connective tissue diseases with overlapping, e.g. to dermatomyositis, progressive systemic sclerosis or Sjögren's syndrome. In view of the variable, heterogeneous disease manifestations, it is obvious that the strategy in SLE therapy is to treat manifestations and not just SLE per se. Using this concept together with pathophysiologically related control parameters and standard clinical investigations, 90 to 95% of SLE patients are adequately treated with NSAID, steroids, antimalarials and immunosuppressiva. Only 5-10% need experimental therapy, and this kind of treatment should be strictly limited to this group.