This article reviews our studies on evaluating the suitability of high-performance immunoaffinity chromatography (HPIAC), an immunoaffinity membrane (IAM) for removing unwanted plasma component, and the safety of the IAM. In an attempt to resolve the problem of amyloid deposition in dialysis patients, we used an HPIAC column, bearing anti-beta 2-microglobulin to remove specifically beta 2-MG from human plasma. The use of a membrane as an affinity ligand support was also studied. A specific antibody immobilized on the membrane was highly effective for the removal of rat immunoglobulin E and of a human serum amyloid P component passed through an extracorporeal circulation (EC) system. Biocompatibility of the specific antibody-bearing IAM was also examined. These techniques should prove useful for medical applications and may have broad applicability to the elimination of any unwanted plasma component. The IAM exerts two functions simultaneously, usual dialysis and elimination by immunoaffinity binding. The rat EC model has been applied as an evaluation system for the safety of medical devices in contact with the blood stream. Combining commonly used hemodialysis (HD) membranes with rat EC, we evaluated the elicitation of immunological responses, as well as the effect of repeated EC. The data suggest that this EC model can reproduce similar immunological responses in HD patients, and can be employed to evaluate medical devices and materials for their delayed, systemic, and repeated exposure effects. The EC system described here can reproduce human HD treatment, remove unwanted substances, and evaluate medical devices and materials for toxicological responses.