Double-filtration plasmapheresis

It is well known that anti-ABO antibodies in the recipient's serum cause hyperacute rejection in ABO-incompatible kidney transplantation. To perform successful ABO-incompatible kidney transplantation, temporary elimination of the anti-ABO antibodies from the recipient's serum is mandatory. Several methods of removing anti-ABO antibodies have been reported: plasmapheresis or immunoadsorption is widely employed in ABO-incompatible kidney transplantation. Two plasmapheresis methods are available, namely, regular plasma exchange by centrifugation or a plasma separator, and double-filtration plasmapheresis (DFPP). DFPP was designed to selectively remove the immunoglobulin fraction from the serum and, as a result, to minimize the volume of substitution fluid required. In this procedure, we usually use 0.5-1.0 L of an 8% albumin solution as the replacement fluid. This is equivalent to 2.5-5.0 L of fresh plasma used in regular plasma exchange. For pretransplant preconditioning, we usually perform DFPP. Three immunosuppressive drugs, such as tacrolimus, mycophenolate mofetil, and methylprednisolone, are administered 7 days before renal transplantation. To remove anti-A and/or anti-B antibodies, the recipients receive 3 or 4 DFPP sessions before the transplantation until the anti-ABO antibody titers have decreased to < or =1:32. A low dose of rituximab (total dosage 200 mg) is given 7 days before renal transplantation and basiliximab is administered at the time of renal transplantation. Between 2005 and 2006, 39 patients were enrolled in this protocol, and only 1 patient could not undergo renal transplantation because their anti-ABO antibody titer was not reduced to the acceptance criterion of ABO-incompatible living-related kidney transplantation (ABO-ILKT), which is 32x dilution. The desensitization success rate using our pretransplant conditioning regimen was 97%. DFPP effectively and safely eliminated anti-ABO antibodies from ABO-incompatible kidney transplantation recipients and contributed to successful ABO-ILKT.