Sirolimus for Refractory Autoimmune Hemolytic Anemia after Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report and Literature Review of the Treatment of Post-Transplant Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) may occur after any type of allogeneic hematopoietic stem cell transplantation (HCT), even ABO-matched transplantation. It tends to be refractory to standard corticosteroid treatment and requires multiple transfusions. Though, there is no consensus regarding the optimal treatment for post-transplant severe AIHA. We present a pediatric patient with refractory AIHA after umbilical cord blood transplantation. She developed severe AIHA at 3 months after transplantation and was unresponsive to multiple treatment modalities, including corticosteroids, intravenous immunoglobulin, plasma exchange and rituximab, resulting in persistent transfusion dependency. Sirolimus, a mammalian target of rapamycin inhibitor, was started on day 67 after the onset of AIHA, and this patient was successfully rescued without any complications. Sirolimus induces apoptosis in autoreactive lymphocytes, increases regulatory T cells and has been reported to have a positive effect on AIHA following solid organ transplantation (SOT). We reviewed the literature regarding post-transplant AIHA in the PubMed database and evaluated the treatment outcome of sirolimus in AIHA after SOT.