Bootcongres

Background In recent years, ABOincompatible kidney donor protocols have been developed, allowing more patients access to kidneys from a living donor, which is considered superior to transplantation with a kidney from a deceased donor. However, it is still unclear what the long-term outcomes of ABOincompatible kidney transplantation are. Methods We conducted a single-centre case control study comparing 10 ABOincompatible (ABO-i) kidney transplantations to 40 ABOcompatible (ABOc) 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 they started triple immunosuppressive treatment (prednisone, mycophenolate mofetil and tacrolimus) two weeks before transplantation. 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. Additionally, all ABOincompatible recipients received IVIG preoperatively. Results ABOi and ABOc 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. ABOi patients did however have more biopsy-proven rejection episodes (50% in ABOi patients vs. 15% in ABOc patients, p = 0,018) for which they received additional immunosuppressive treatment. This resulted in significantly more infections (1,7 infections per ABOi patient vs. 0,9 infections per ABOc patient (p = 0,045). The number of days in the hospital in the first year post-transplantation was also higher in the ABOi 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 ABOi transplantations can be performed safely and 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 ABOi kidney transplantation.