Selective plasma component removal: alternatives to plasma exchange

Plasma exchange, the unselective removal of all plasma constituents, has been applied, with varying degrees of success, to an increasing number of disorders. Because of the high cost of plasma exchange, largely the result of expensive homologous replacement solution, and other reasons, alternatives have been sought. Selective removal of plasma components permits the use of autologous plasma as replacement which is less costly, more physiologic, and in some cases, a more efficient alternative to plasma exchange. The selective removal of plasma components whose presence is associated with a disease process can be accomplished presently by physical or chemical means with either on-line of off-line systems. A state-of-the-art review of currently available alternatives to plasma exchange is described. This includes hemoperfusion and plasmaperfusion over affinity columns or filters with immobilized sorbents. On-line separation of macromolecules by membrane filtration and cryoprecipitation as well as off-line chemical precipitation and cryoprecipitation are also described. The potential and limitations of the techniques are emphasized.