Extracorporeal immunoadsorption therapy on rats. In vivo depletion of specific antibodies.

A technique for extracorporeal immunoadsorption of circulating specific antibodies from the plasma of rats is described. Catheterization of rats was performed using the carotid and the jugular blood vessels. The rats were treated non-anaesthetized. Blood was pumped continuously through a hollow-fibre plasma filter at a rate of 1.5 ml/min and plasma was separated and passed through an adsorbent column at a flow of 0.2 ml/min. The treated plasma was mixed with the blood cells before being returned to the rat. The column contained the antigen covalently linked to agarose beads. About three plasma volumes were treated during a period of 3 h and 30 min, which resulted in an antibody depletion of about 90-95%. The antibody levels returned to pre-adsorption levels after 4-5 days, or in some cases even exceeded the titres before treatment.