Specific removal of DNA antibodies in vivo by extracorporeal circulation over DNA immobilized in collodion charcoal

A novel immunoadsorbent is described in which significant quantities of DNA were immobilized in collodion membranes adherent to activated charcoal particles. DNA-collodion-charcoal particles were placed in an extracorporeal circulation system and arterial blood was circulated through a continuous-flow celltrifuge in which plasma was separated from formed elements. Rabbit anti-BSA and human anti-DNA antibodies were infused into mongrel dogs and only plasma was pumped through the DNA-collodion-charcoal immunoadsorbent. A sharp reduction in DNA binding activity was observed over the ensuing 15 to 30 min with only slight change in BSA binding during the same time period. There were no significant changes in [¹²⁵I] DNA on the charcoal before and after the perfusion experiments and there was no recovery of [¹²⁵I] DNA in serum, urine, or vital organs at the conclusion of the studies. In addition, there were no demonstrable hematologic or biochemical alterations in the dogs. These findings suggest that this extracorporeal immunoadsorbent system may rapidly and specifically withdraw DNA antibodies in vivo with minimal host toxicity. As such, it would appear to offer a specific approach to therapy of systemic lupus erythematosus when it is desirable to remove circulating DNA antibodies.