The pathogenesis of most autoimmune diseases directly involves CD4(+) helper T cells. To remove CD4(+) T cells selectively from the circulation, we designed a new column in which an anti-CD4 monoclonal antibody was immobilized on the activated substance. Nearly 90% of CD4(+) T cells were selectively adsorbed from whole blood with a single passage through the column in vitro, resulting in depletion of the antigen-specific T cell responses. We conclude that this new column would be potentially useful for treatment of T cell-mediated autoimmune diseases.