Prevention of acute rejection after rescue with Belatacept by association of low-dose Tacrolimus maintenance in medically complex kidney transplant recipients with early or late graft dysfunction

BACKGROUND: Increased acute rejection risk in rescue protocols with Belatacept may limit its use particularly in medically complex patients where preexisting increased risk of rejection couples with CNI toxicity. METHODS: Retrospective analysis was performed in 19 KTs shifted to a Belatacept-based immunosuppression with low-dose Tacrolimus (2–3 ng/mL) after evidence of allograft disfunction, including patients with primary non-function (PNF), chronic-active antibody-mediated rejection (cAMR), history of previous KTs and/or other concomitant transplants (liver, pancreas). Evaluation of CD28(+) CD4(+) effector memory T cell (T(EM)) before conversion was performed in 10/19. RESULTS: Kidney function significantly improved (median eGFR 16.5 ml/min/1.73m(2) before vs 25 ml/min after; p = 0.001) at a median time after conversion of 12.5 months (9.1–17.8). Overall graft and patient survival were 89.5% and 100% respectively. Definitive weaning from dialysis in 5/5 KTs with PNF was observed, whereas 7/8 patients lost their graft within first year in a control group. eGFR significantly ameliorated in re-trasplants (p = 0.001) and stabilized in KTs with other organ transplants or cAMR. No acute rejection episodes occurred, despite the significant risk suggested by high frequency of CD28(+) CD4(+) T(EM) in most patients. Opportunistic infections were limited and most common in early vs late-converted. CONCLUSIONS: Rescue association of Belatacept with low-dose Tacrolimus in medically complex KTs is a feasible option that allows prevention of acute rejection and amelioration of graft function.