Biocompatibility of extracorporeal immunoadsorption systems

Following the first publication of a technique aiming for clinical application in 1969, extracorporeal immunoadsorption is increasingly finding a place among haemapheresis techniques. The apparent advantages outweigh the technical difficulties and economical drawbacks still connected with this treatment modality. At present three different developments are under clinical investigation: Staphylococcus Protein-A based immunoadsorption (SpA) the antibody-mediated adsorption (therapeutic affinity chromotography) and hydrophobic interactionbased immunoglobulin adsorption. The exact binding capacity and mechanism has not been completely elucidated for SpA and amino acid-based techniques. The lack of knowledge about pathogenic substrates exclusively responsible for the pathogenicity of many diseases, appears to be the major drawback for the prospective development of affinity chromatography-based extracorporeal systems. The practical application of molecular-biologic diagnostic procedures with a high grade of detection specificity (monoclonal antibodies) appears to be promising for the development of extracorporeal immunoadsorption. The immunomodulatory effect that results from the interaction of blood and plasma with artificial surfaces is an interesting subject of investigation, derived mainly from biocompatibility studies. The careful clinical and laboratory investigation of the biocompatibility of extracorporeal immunoadsorption systems contribute considerably to the prevention of undesired side effects.