Specific removal of antibodies with an immunoadsorption system.

A continuous flow immunoadsorption system consisting of a cell separator, protein A-sepharose columns, and a semi-automatic elution component was developed to specifically remove circulating IgG. This system provides extensive absorption with an essentially unlimited column bed volume. Six dogs were treated a total of 19 times. In no case did fever, sepsis, or respiratory distress result from the treatment. Serial blood counts and tests of liver and renal function remained in the normal range. Ex vivo perfusion of one plasma volume caused an acute drop in IgG levels of approximately 50 percent. This was reflected in a similar decrease in specific antibody levels to sheep erythrocytes, bovine serum albumin, and canine parvovirus. Antibody kinetics following immunoadsorption were variable, but in several cases, antibody levels remained lowered. This immunoadsorptive system appears to be a safe and effective alternative to plasma exchange for removal of IgG antibodies.