Stable graft function on low-dose steroid monotherapy in spite of donor-specific antibodies in renal transplantation combined with stem cell infusion.

Transplantation using immunosuppression/induction therapies has controlled acute rejections; however, there is no answer for chronic graft attrition. Donor-specific antibodies (DSA) are believed to cause antibody mediated rejections eventually causing chronic graft loss. Regulatory T cells (T-regs) are believed to protect the graft from immune injury. We report a 53-year-old woman transplanted with her son's kidney using donor-specific transfusion and stem cells (SC) under non-myeloablative conditioning of cyclophosphamide, anti-T and anti-B-cell antibodies and Bortezomib. The patient was on low-dose steroid monotherapy under immune monitoring of DSA and serum creatine. Graft biopsy at 1 and 3.5 years post-transplant was unremarkable in spite of the presence of DSA. Peripheral T-regs (pTregs) at 3.5 years post-transplant were 3.54%. This case shows that DSA are not necessarily detrimental to the renal allograft. We further hypothesise that pTregs were induced from SC and sustained to protect this graft from cytotoxic T cells and DSA.