Immunoadsorption of human plasma with protein A‐sepharose columns

Four patients with refractory acute leukemia were treated a total of 31 times with an immunoadsorption system consisting of protein A-sepharose columns, a cell separator, and an elution monitor to test its safety and capacity to remove immunoglobulins. The procedure was tolerated well, and acutely reduced plasma IgG levels by approximately 18 percent. When the procedure was repeated two to three times per week for 3 weeks, IgG levels dropped by 30 to 40 percent, but they gradually returned to pretreatment levels after completion of the course of treatment. Single columns became saturated with IgG after approximately 1500 ml of plasma had passed through the columns. The use of multiple columns sequentially provided continuous extraction of immunoglobulin. One patient regained responsiveness to platelet transfusions after removal of platelet antibodies. These preliminary studies suggest that this immunoadsorption system is effective for specifically removing IgG and that it merits further clinical testing.