Specific extraction of antigen in vivo by extracorporeal circulation over antibody immobilized in collodion-charcoal.

A novel extracorporeal immunoadsorbent is described in which anti-bovine serum albumin (anti-BSA) was entrapped in collodion membranes adherent to activated charcoal particles. This immunoadsorbent was capable of specifically removing circulating BSA in vitro and in vivo in an extracorporeal system in dogs. In preparation of the immunoadsorbent, up to 81.2% of added anti-BSA was retained on collodion-charcoal. In vitro circulation studies demonstrated that anti-BSA collodion-charcoal removed 812% more 125I-BSA than control colloidon-charcoal. For in vivo studies, an extracorporeal circulation system was established and arterial blood was passaged through a continuous flow celltrifuge wherein plasma which was separated from formed elements of the blood was circulated over anti-BSA and control rabbit gamma-globulin collodion-charcoal. 125I-BSA was passively infused into mongrel dogs, and plasma was then circulated over extracorpeal immunoadsorbents for 2 hr. Results showed up to 896% greater uptake of circulating 125I-BSA on the charcoal containing immobilized anti-BSA compared to control charcoal. There was no evidence of release of anti-BSA from the immunoadsorbent since 125I-anti-BSA cpm on the charcoal before and after the experiments were unchanged. In addition, there were no significant alterations in hematocrit, leukocyte counts, serum sodium, potassium, calcium, magnesium, or creatinine levels before and after in vivo procedures. These data suggest that this immunoadsorbent consisting of anti-BSA immobilized in collodion membranes adherent to charcoal particles may specifically withdraw circulating antigens in vivo with minimal release of entrapped antibodies and no significant alteration in the host hematologic and biochemical status.