Belatacept has been introduced as a promising novel immunosuppressant to the field of transplantation, especially for patients suffering from adverse effects of conventional immunosuppression such as nephrotoxicity. Analysis of rejection episodes under costimulation-based regimen in kidney transplants suggested that high percentages of circulating CD4+CD57+PD1− cells pre-transplantation may be predictive markers for belatacept-resistant acute rejection (BRR)(1). We investigated this particular subset in one of our face transplant recipients who experienced complications of CNI-based immunosuppression.

Our patient received a face transplant in March 2014. On triple immunosuppression regimen–tacrolimus (target trough level of 6 ng/ml), mycophenolate mofetil (MMF) 1 g twice daily and prednisone 5 mg daily, he experienced progressive nephrotoxicity, neurotoxicity and refractory CMV viremia. He was continued on MMF/steroids but then switched to rapamycin 11 months after transplantation, which temporarily improved his renal function (Fig. 1A) and reduced CMV viremia (Fig. 1B) but led to significant lower extremity swelling, worsening renal function with proteinuria and two episodes of cellular rejection (grade II and III, respectively). Because of these complications, he was then converted to belatacept 14 months post-transplant. This improved and stabilized his kidney function (serum creatinine reduction from 2.2 to 1.5 mg/dL with resolution of proteinuria)(Fig. 1A), and in combination with antiviral therapy since month 9 led to a remission of CMV viremia (Fig. 1B). However, 4 months after conversion, our patient developed an episode of rejection