Tydén G et al. (2007) Implementation of a protocol for ABO-incompatible kidney transplantation—a three-center experience with 60 consecutive transplantations. Transplantation 83: 1153–1155

A new protocol for ABO-incompatible kidney transplantation was proposed in 2001 after preliminary success at a transplant center in Stockholm, Sweden. Now, Tydén and coauthors report on the successful implementation of the protocol at this center and at two other institutions, in Uppsala, Sweden, and Freiberg, Germany. No differences were found between the outcomes of 60 consecutive patients who received ABO-incompatible living-donor transplants under the new protocol and those of 274 patients who received ABO-compatible living-donor transplants during the same period.

The new protocol comprises the following: preoperative antigen-specific immunoadsorption to remove existing ABO antibodies; single-dose rituximab (375 mg/m2 4 weeks before immunoadsorption) and intravenous immunoglobulin (0.5 g/kg before transplantation) to prevent antibody rebound; and conventional immunosuppression with tacrolimus, mycophenolate mofetil and prednisolone, started about a week before immunoadsorption. After a mean follow-up of 17.5 months (range 2–61 months), ABO-incompatible graft survival was 97%, and the mean serum creatinine level of recipients was 127 µmol/l (1.44 mg/dl); corresponding figures for ABO-compatible grafts were 95% and 133 µmol/l (1.50 mg/dl). Of the two graft losses observed with the new protocol, one was attributed to noncompliance with the immunosuppressive regimen, and one was the result of patient death from Clostridium sp. infection at 4 months. Patient survival was 98% in each group.

No late rebound of antibodies or humoral rejection was observed under the new protocol. Substantial institutional variation in antibody titers led to a marked difference in the number of immunoadsorption sessions required, indicating a need for a standardized fluorescence-activated cell-sorting technique.