Optimizing outcomes for haploidentical hematopoietic stem cell transplantation in severe aplastic anemia with intensive GVHD prophylaxis: a review of current findings.

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has resulted in increased levels of disease-free survival in severe aplastic anemia (SAA). Haploidentical transplantation (haplo-SCT) was previously not recommended due to unacceptable incidences of graft-versus-host disease (GvHD) and graft failures. With the advent of intensive GvHD prophylaxis strategies, the outcomes obtained with haplo-SCT for SAA have gradually improved.Areas covered: A comprehensive search considered PubMed reported articles before 1 February 2021, presented abstracts, and clinical trials pertaining to haplo-HSCT for SAA. This manuscript covers modern approaches with intensive GvHD prophylaxis in haplo-SCT for SAA. The representative methods consist of granulocyte colony stimulating factor (G-CSF) plus ATG-based and posttransplantation cyclophosphamide (PT-Cy)-based protocols.Expert opinion: Currently, haplo-SCT has become a feasible option for treating SAA. The G-CSF/ATG-based protocol included the largest sample size and reported comparable survival rates with identical siblings. The PT-Cy protocol resulted in a relatively lower incidence of GvHD and seemingly poorer but continuously improved engraftment with augmented conditioning. The optimized outcomes are constantly updated with the modification of the conditioning regimen, donor selection, graft source and GvHD prophylaxis. In the future, we should pay more attention to quality of life in addition to survival, and personalized haplo-SCT may improve outcomes.