Belatacept-based immunosuppression in heart transplant recipients: A single center experience

We aim to describe the effect of belatacept on de novo donor-specific antibodies (DSA) formation, rejection, and renal function in heart transplant recipients.

The cohort comprises 60 adult heart or heart-kidney recipients transplanted between 2005 and 2022. Twelve recipients initialized at ∼90 days post-transplantation on a belatacept-based immunosuppression regimen with tapered tacrolimus trough levels were matched to 48 standard tacrolimus-based regimen controls. Differences in the distribution of recipients with emergent de novo DSA and rejection were assessed over the first 85 days baseline period, the average duration pre-belatacept. Survival analysis assessed regimen group differences in the probability of remaining de novo DSA and rejection free over the follow-up period spanning 86 to 540 days. Renal function and cytomegalovirus viremia were examined as secondary outcomes.

There were no statistically significant regimen group differences in the distribution of recipients with de novo DSA or rejection during the baseline period. Furthermore, differences in the probability of remaining de novo DSA and rejection free during the follow-up period remained insignificant (log-rank test, p = 0.12). Belatacept-treated recipients, at follow-up, had no incidence of developing de novo DSA, unlike 19% of the controls. Additionally, there were no statistically significant differences in acute cellular and antibody mediated rejection events, renal function, and CMV viremia by regimen group.

Recipients treated with belatacept-based regimen exhibited a trend of reduced de novo DSA development compared to standard tacrolimus-based regimen controls. Larger studies are needed to evaluate the benefit of belatacept use in heart transplant populations.