PubMed1984
A new biocompatible collagen membrane, chemically activated in order to bind several antigens such as albumin or DNA, was successfully used to perform extracorporeal immunoadsorptions (IA) in vivo. First, immunoadsorbent devices composed of albumin-coated membranes, in a multilayer arrangement, were able to remove a large amount of anti-albumin antibodies from dogs actively immunized against heterologous albumin, during a single hemoperfusion. Second, DNA-coated membranes, in the same disposition, were used in 5 SLE-patients for serial plasma perfusions, which resulted in a significant decrease of anti-DNA antibodies (DNA-Ab) and immune complexes in serum. As previously observed in dogs, IA were sometimes followed by a rebound of DNA-Ab levels, which occurred either between successive IA (fast rebound) or 2 weeks after the series of IA, only in patients receiving the lowest steroid dosages. The main factors involved in such a rebound are probably a reequilibration of the antibody pool between the intra- and extravascular spaces, for the "fast" component of this rebound, and a de novo antibody synthesis induced by antibody removal only. Indeed, the hypothesis of a direct stimulation by either antigen release or contact between lymphocytes and antigen linked on the membrane, were ruled out by the results of in vitro studies and of plasma perfusion alone. These results support the usefulness of antigen-coated collagen membranes for in vivo IA, which represent a new approach to the treatment of autoantibody mediated diseases and to the investigation of the factors governing antibody synthesis.