Impact of positive PRA on the results of ABO-incompatible kidney transplantation

Abstract

Introduction Due to the continuing shortage of cadaveric donors in Japan, ABO-incompatible living kidney transplantation (LKT) is being performed. It is well known that highly sensitized patients with positive panel reactive antibodies (PRA) often present with acute rejection. Therefore, we examined the impact of a positive PRA on the results of ABO-incompatible LKT. Materials and methods One hundred seventy-seven recipients underwent ABO-incompatible LKT between January 1989 and March 2003. Of these patients, 37 who had been examined for PRA before transplantation were included in this study. There were 25 men and 12 women of mean age 37.3 years. Plasmapheresis was performed to remove anti-ABO antibodies before transplantation. During the induction phase, methylprednisolone, azathioprine, or mycophenolate mofetil and cyclosporine or tacrolimus were used for immunosuppression. Splenectomy was performed at the time of kidney transplantation in all patients. PRA was measured using FlowPRA by flow cytometer. Results Eight of the 37 patients had a positive PRA before transplantation (class I, 5; class II, 1; class I and class II, 2). The incidence of acute rejection was 37.9% in the patients with a negative PRA and 37.5% in patients with a positive PRA. One patient with a negative PRA and one patient with a positive PRA lost grafts due to acute rejection. Conclusions Positive PRA may not increase the incidence of acute rejection in ABO-incompatible LKT because plasmapheresis and splenectomy are performed to eliminate anti-ABO antibody.