Patients undergoing ABO-incompatible kidney transplantation must have their anti-donor blood-type antibody titer (ADBT) reduced to below 1:16 by using either plasma-exchange (PEX) or double filtration plasma exchange (DFPP) before they can safely undergo a transplantation. The ADBT can be reduced to under 1:16 in most cases; however, some cases (non-responders) do not respond to PEX or DFPP treatment. To enable kidney transplantations to be performed in non-responders, we developed a new preconditioning regimen consisting of anti-CD20 monoclonal antibody (rituximab) infusions, a splenectomy, and DFPP. Four non-responders were infused with rituximab at a dose of 375 mg/m(2) weekly for 3-4 wk and splenectomized 1 or 2 wk before transplantation. Four to five DFPP-sessions were then performed after the splenectomy. Using this preconditioning regimen, the ADBT was reduced to below 1:16, enabling kidney transplantations to be successfully performed in all patients. After the kidney transplantation, no episodes of humoral rejection were observed, and only one episode of cellular rejection was encountered. The cellular rejection was associated with a reduction in immunosuppressant administration because of CMV infection that occurred 80 d after the kidney transplantation. The renal allografts were functioning well in all patients after a mean follow-up period of 390 d. No serious complications or side effects were encountered. We have developed a new preconditioning regimen that enables PEX and DFPP non-responders to undergo ABO-incompatible kidney transplantations.