Fludarabine-based nonmyeloablative stem cell transplantation for sickle cell disease with and without renal failure: clinical outcome and pharmacokinetics.

End-organ damage is common in patients with sickle cell disease (SCD) thereby limiting the use of allogeneic stem cell transplantation (SCT). We report the outcome of 2 adult SCD patients, 1 with end-stage renal disease (ESRD), who underwent fludarabine-based nonmyeloablative SCT from HLA-identical matched siblings. To prevent fludarabine toxicity, the patient with ESRD underwent aggressive dialysis following adjusted fludarabine dosing. Pharmacokinetics of the fludarabine metabolite F-Ara-A was studied on the patient with ESRD and 2 additional patients with normal renal function. Both patients with SCD achieved full donor erythroid chimerism, have normal blood counts, and are on no immunosuppressive medications. With a 20% dose reduction followed by daily dialysis, we achieved fludarabine drug exposure that is nearly identical to that achieved in patients with normal renal function. We conclude that fludarabine-based nonmyeloablative allogeneic SCT for adult patients with SCD is feasible, even in the setting of ESRD.