الفهرس 
PLASMAPHERESISOnly 14 pages are availabe for public view
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Abstract
A
imed at eliminating circulating immunecomplexes (IC), plasmapheresis was one of the first pathophysiologically based concepts. Numerous studies have been published documenting the benefit of plasmapheresis in acute situations of systemic autoimmune diseases and a number of other diseases. With more than 20 years experience, plasmapheresis and other extracorporeal therapies, e.g. immunoadsorption and leukapheresis, are now fairly old therapeutic options, but the discussion about their value is still ongoing. The reasons are multiple; one major obstacle is that important pathogens and therapeutic targets have been defined in only a small number of disorders. Also, the general therapeutic options of autoimmune diseases have improved and only few indications seem to be open for extracorporeal treatments.
In SLE, previous studies found no clinical efficacy of plasmapheresis in mild SLE, while others reported little benefit in the first two years of observation.
The conclusion of these studies denoted there was no need to treat SLE patients with plasmapheresis, since it provides no significant effect and is a rather high-risk, and expensive method. The long list of case reports and uncontrolled trials with good responses fails to give convincing evidence of the value of plasmapheresis, although the approximately 70% responder rate in lupus nephritis and acute flares suggests quite a good overall effect.
Although controlled trials in other autoimmune diseases came to similar conclusions, extracorporeal treatments offer some major advantages that should be used at the proper time and for appropriate indications. The rationale for use of plasmapheresis and immunoadsorption is given by the basic principles of extracorporeal treatments, which are most intensively investigated in SLE, the prototype of human diseases mediated principally by IC.
The benefit of plasmapheresis is also influenced by the substitution fluid. Plasmapheresis is unselective removal of all plasma proteins. Only very few of the removed substances are pathogenic, and something beneficial that counteracts the process of immunologically mediated tissue injury, e.g. complement, may also be removed.
It is obvious that plasmapheresis is most effective in diseases with more intravascular circulating IC and with a limited amount of continuously synthesized antibodies. However, there are examples suggesting that the efficacy of plasmapheresis is not restricted to the intravascular space. The best results are obtained in diseases with a temporally limited antibody production.
It may also be concluded from better results obtained with plasmapheresis using fresh frozen plasma instead of albumin as substitution. Also, clinical responses lasted longer when fresh frozen plasma was used.
Thus, there are at least two effects of plasmapheresis; but how can antibody removal and enhanced RES clearance be used to help patients? To answer this question, one has to look at the regulatory events induced by plasmapheresis, at the indications of extracorporal methods and, at side effects.
The list of possible side effects is long. They may be related to the substitution fluid, e.g. the risk of virus infections from fresh frozen plasma; to technical problems, e.g. venous access; and to intercurrent diseases. Only 3% of patients treated with plasmapheresis will develop serious complications.
Most of the retrospectively evaluated negative effects in patients treated with plasmapheresis are not time-related to the treatment and may only document the severe illness of those patients. In general, plasmapheresis is safe, especially in comparison with immunosuppressive drugs used in systemic autoimmune diseases.