A method for reducing the number of selected antibodies in a subject's blood, the method comprising removing blood from the subject, passing the blood along an enclosed pathway, wherein the pathway comprises one or more semi-permeable hollow fibers with one or more membranes having surfaces positioned substantially perpendicular to the length of the one or more hollow fiber and antigens specific for the antibodies immobilized on the one or more membranes, returning the treated blood to the internal circulation of the subject, wherein the returned treated blood has a reduced number of selected antibodies compared to before treatment.
