Mixed chimerism after allogeneic hematopoietic stem cell transplantation for severe aplastic anemia

Background: Mixed chimerism (MC) frequently occurs in patients with severe aplastic anemia (SAA) after allogeneic hematological stem cell transplantation (allo-HSCT).Methods A retrospective study on 287 SAA who underwent allo-HSCT between October 2012 and January 2020 was conducted to explore the outcomes, risk factors treatment options for MC. Among AA excluded Fanconi (FA), Congenital dyskeratosis (DKC), Paroxysmal nocturnal hemoglobinuria (PNH), etc.112 matched sibling donor (MSD)-HSCT, 91 unrelated donor-HSCT 84 haploidentical-HSCT. Patients were divided into following 4 groups: group 1: Donor (DC); 2: MC without cytopenia; 3: 4: secondary graft failure (SGF).Results Compared other three groups, SGF predicted a poor prognosis of (P< 0.001). In addition, associated early (within 3 months transplantation) presence high levels Uni- multivariate logistic regression analysis showed that donor/recipient sex-mismatching CTX + ATG regimen high-risk Of note, cytopenia (group 3), effective response rate reached 55% (6/11) enhanced immunosuppression combined cellular therapy, while only one four received alone.Conclusion prognosis, increased recipient chimerism. The based MSD-HSCT Cellular therapy could improve progressive