ABO-Incompatible Kidney Transplantation Outcomes: A Single Center Experience.

Abstract

Background In recent years, ABO-incompatible kidney donor protocols have been developed, allowing more patients access to kidneys from a living donor. However, it is still unclear what the long-term outcomes of ABO-incompatible kidney transplantation are. Methods We conducted a single center case control study comparing 10 ABO-incompatible (ABO-i) kidney transplantations to 40 ABO-compatible (ABO-c) kidney transplantations. Controls were matched by gender, age and follow-up period. ABO-i recipients were treated with a single dose of rituximab four weeks before transplantation and started triple immunosuppressive treatment (prednisone, mycophenolate mofetil and tacrolimus) two weeks before transplantation. All ABO-incompatible recipients received IVIG preoperatively. Immunoadsorption was conducted at least four times preoperatively, with additional sessions being performed if the target anti donor blood type IgG ≤ 1:8 had not been reached. Postoperatively, 3 immunoadsorptions were conducted. Results ABO-i and ABO-c patients were followed for a median period of 2,25 vs. 2,5 years respectively. There was no significant difference in patient and graft survival. Kidney function (as measured by creatinin clearance, MDRD and proteinuria) was also not significantly different, although there was a trend toward a lower kidney function in ABO-i patients. ABO-i patients had more biopsy-proven rejection episodes (50% in ABO-i vs. 15% in ABO-c, p=0,018) for which they received additional immunosuppressive treatment. This resulted in significantly more infections (1,7 infections per ABO-i patient vs. 0,9 infections per ABO-c patient, p=0,045). The number of days in the hospital in the first year post-transplantation was also higher in the ABO-i group (24 vs. 15,5 median days). In linear regression analysis, higher baseline anti donor blood type IgG were predictive of a lower kidney function during follow-up. Conclusion ABO-i transplantations can be performed successfully, without a significant difference in patient and graft survival after a median follow-up of 2,25 years. However, patients are at increased risk of rejections and infections. Patients with high anti donor blood type IgG are not suitable candidates for ABO-i kidney transplantation.