Attenuation of Canine Nephrotoxic Glomer-ulonephritis with an Extracorporeal Immuno-adsorbent

Abstract

A novel immunoadsorbent is described in which soluble canine glomerular basement membrane (GBM) antigen was immobilized in collodion membranes adherent to small charcoal particles. As much as 80% of the added GBM antigen was retained in the collodion-charcoal. The binding of anti-GBM antibody to immobilized GBM antigen in vitro and in vivo was demonstrated. For in vivo studies, an extracorporeal circulation system was established, and mongrel dogs were then injected i.v. with anti-GBM antibodies. Whole blood was circulated at 100 ml/min over GBM collodion-charcoal for 4 h. Renal tissue was examined by fluorescence and light microscopy for the deposition of heterologous .gamma.-globulin and glomerular inflammation before and after the extracorporeal procedure. Results showed less deposition of heterologous Ig[immunoglobulin]G and less inflammation in experimental dog kidneys than in control kidneys. There was no evidence of release of 131I-labeled GBM from the immunoadsorbent at the conclusion of perfusion experiments and no significant biochemical or hematologic alterations. Etracorporeal immunoadsorbent treatment was capable of attenuating the early heterologous phase of passive canine nephrotoxic nephritis and may have a potential role in the therapy of anti-GBM antibody mediated nephropathy.