ABO Incompatible Renal Transplantation without Augmented Immunosuppression or Antibody Removal - Report of 10 Cases

Abstract

Introduction: Many centres now perform renal transplants from live donors into ABO blood group incompatible (ABOi) recipients. Treatment protocols are varied but include some or all of pre-transplant rituximab, splenectomy, IVIG, T-cell depleting antibody induction, and antibody removal. The aim of such treatment is to reduce recipient ABO antibody titres to ‘safe’ levels (typically a titre of 1:8 or less) on the day of transplant. Here we report 10 successful ABOi transplants in patients with a baseline titre of 1:8 or less, none of whom received antibody removal or augmented immunosuppression. Methods: Between 2006 and 2011 20 patients have received an ABOi live donor transplant at our centre. In 10 of these the baseline IgG and IgM ABO antibody titres (measured using DiaMed gel-cards) were consistently 1:8 or less (1:8 for 3 patients, 1:4 for 3 and 1:2 for 4). Five of these patients were blood group O, with two A1, two A2 and one group B donor. The other 5 recipients were group A, with two AB and three B donors. Results: All patients received basiliximab induction followed by tacrolimus, MMF and prednisolone maintenance immunosuppression. All patients had primary graft function. There have been no episodes of either biopsy-proven or clinically determined rejection. 8 patients have stable graft function with a mean serum creatinine (SCr) of 111μmol/L (range 86-140) after 21 months follow up (2-74). One patient required ureteric reimplantation after a period of obstruction, and now has a stable SCr of 198μmol/L at 2 years follow up. The tenth patient has impaired graft function with SCr of 185μmol/L in the setting of very substantial weight gain. Conclusions: ABOi live donor renal transplantation can safely be performed without antibody removal or enhanced immunosuppression in patients with a baseline antibody titre of 1:8 or less. We suggest that ABO antibody titres should be measured in all patients with an ABOi live donor. We also believe that ABO antibody titres may usefully be measured in ABO group O patients on deceased donor waiting lists. ABOi kidneys could be offered to those with low titres, something that may be of particular benefit to HLA sensitized group O patients.