Clinical experience with a new apheresis filter that specifically depletes ABO blood group antibodies

Although living kidney donors are increasingly being used, in most centers, 30 to 40 percent of potential donors are being turned down due to ABO mismatch. A protocol for ABO-mismatched kidney transplantation without splenectomy and with antigen-specific adsorption of ABO antibodies instead of nonspecific plasmapheresis was therefore designed.

The immunosuppressive protocol used at the Department of Transplantation Surgery, Karolinska University Hospital, Stockholm, Sweden, together with relevant clinical data for 11 of the studied patients, have been described previously. The protocol called for immunoadsorption of ABO antibodies on Days -6, -5, -2, and -1 and on Days +2, +5, and +8. Patient plasma was recirculated through a new apheresis filter, the Glycosorb ABO column (Glycorex Transplantation AB), containing synthetic terminal trisaccharide A or B blood group antigen linked to a Sepharose matrix.

Since 2001, 15 patients, including 2 infants, have been successfully transplanted with ABO-mismatched kidneys from living donors. The donor-recipient blood groups were A1-O (n = 5), A2-O (n = 2), B-O (n = 4), B-A (n = 2), and A1B-B (n = 2). ABO antibody titers at transplantation did not exceed immunoglobulin G 4 or immunoglobulin M 4 levels. No humoral rejections and no late rebound of ABO antibodies were observed. No adverse effects related to immunoadsorption treatment have been recorded.

It is concluded that ABO-mismatched kidney transplantations can be successfully performed without splenectomy and that ABO antibodies can be effectively and safely depleted with the Glycosorb ABO column.