Successful ABO‐incompatible heart transplantation in a child despite blood‐group sensitization after ventricular assist device support

Abstract

In the first two yr of life blood-group incompatible (ABO-incompatible) heart transplantation can be performed leading to immune tolerance to donor blood group. Antibody titers should be below 1:4. VAD use is correlated with sensitization toward blood-group antigens. A boy was diagnosed with dilated cardiomyopathy at nine months of age and listed for 0-compatible transplantation. Progressive heart failure required implantation of a left VAD. His listing was extended for ABO-incompatible transplantation despite antibody titers of 1:32 anti-A and 1:8 anti-B. After 26 days on VAD, he was transplanted with a B donor heart. No hyperacute or acute rejection occurred in 12 months post-transplant. Anti-B antibodies rose to a maximum of 1:2. No use of rituximab or plasmapheresis was required. There are no signs of graft vasculopathy. This indicates that inclusion criteria for ABO-incompatible transplantation may be extended to immediate cases. This is the first case with a healthy immune system to show signs of tolerance development after ABO-incompatible heart transplantation with increased prior antibody titers and without specific treatment.

A current era analysis of ABO incompatible listing practice and impact on outcomes in young children requiring heart transplantation

“…3,5,6 In the PHTS database, 82 patients aged 2 years or older were reported listed for ABOi. The published literature on successful ABOi HTx in patients outside the currently assumed boundaries of age and antibody titers are currently limited to case reports 15,16 and small cohort studies. 17 In selected patients and with preventive immunologic intervention, ABOi HTx was successfully performed in adult patients 18 and is routine in some countries for adult kidney transplantation.…”

Pushing the boundaries: The current status of ABO-incompatible cardiac transplantation

“…66 Fortunately, immune up-regulation does not appear to have an effect on the development of tolerance to the donor blood group after transplantation. 67 There a few recent publications that have included outcomes after ABOi transplantation in patients with higher levels of pre-transplant isohemagglutinins, as outlined in Table 1.…”

ABO-incompatible hearts for infant transplantation

“…No cases of ABOrelated hyperacute rejection were reported, nor differences in survival or graft function when compared with ABO-compatible (ABOc) transplants. Included in these reports were instances of successful ABOi transplantation in complex situations including mechanical circulatory support with extracorporeal membrane oxygenation or ventricular assist devices in which passive administration of isohemagglutinin-containing blood products such as blood group O plasma and/or platelets could mask the degree of endogenous antibody production, thus making it difficult to gauge accurately the suitability of a patient for ABOi transplantation [17][18][19].…”