Development of a DNA-adsorbent for the specific removal of anti-DNA autoantibodies in systemic lupus erythematosus (SLE).

Autoantibodies against DNA are of primary importance for the diagnosis and pathogenesis of systemic lupus erythematousus (SLE). The level of anti-DNA antibodies correlates well with the disease activity and renal involvement. In such patients the removal of anti-DNA antibodies from plasma may lead to a clinical improvement. For this reason an adsorbent was made by covalent coupling of calf thymus DNA to a solid support based on ethylene dimethacrylate cross-linked hydroxethyl methacrylate. Up to 2.5 mg of DNA were immobolized to 1 ml of the support activated chemically by aminosilane and glutaraldehyde. The incubation of 40 ml of SLE plasma with 1 ml of the adsorbent resulted in a 50% decline in anti-DNA activity. There was no release of immobilized P-32-DNA into the plasma. Biocompatibility, sterilisation, and reapplication (without loss of binding capacity) of the adsorbent could be demonstrated. We concluded that the adsorbent may be suitable for treatment.