Immunoadsorption in myasthenia gravis based on specific ligands mimicking the immunogenic sites of the acetylcholine receptor.

A specific system for antibody removal from blood circulation in myasthenia gravis (MG) patients was devised by use of the immunoadsorbent bound to an acetylcholine receptor (AChR) peptide that was synthesized corresponding to the sequence of residues 183-200 of the AChR alpha-subunit (alpha 183-200), antibodies which prevent the binding of ACh to AChR. The alpha 183-200 peptide was confirmed to be immunogenic for induction of an animal model of the disease and for reactivity with MG autoantibodies. We then made use of these results for immunoadsorption therapy through the antigen-antibody reaction on the molecular level, having given patients relief from myasthenic weakness. The greatest care was taken for the selection of an antigenic region in the molecular structure among various myasthenogenic domains of AChR and for the antigenic conformation of synthetic peptide as the adsorbent to react with antibodies raised against the native protein.