Acquired aplastic anemia:Is bystander insult to autologous hematopoiesis driven by immune surveillance against malignant cells?

We previously reported a serendipitous finding from a patient with refractory severe aplastic anemia who had gotten an unexpected hematological response to treatment with gut-cleansing preparations(GCPs).This patient experienced three recurrences over the ensuing one year of intermittent GCP treatments,with each recurrence occurring 7-8 wk from a GCP.After his third recurrence,he was prescribed successive treatment with rifampicin,berberine,and monthly administered GCP for 4 mo,and he developed an erythroid proliferative neoplasma and an overwhelming enteropathy,and eventually died of septic shock.Laboratory investigations had validated the resolution of myelosuppression and the appearance of malignant clonal hematopoiesis.From the treatment process and laboratory investigations,it is reasonably inferred that the engagement of gut inflammation is critically required in sustaining the overall pathophysiology of acquired aplastic anemia probably by creating a chronic inflammatory state.Incorporation of rifampicin,berberine,and monthly GCP into cyclosporine can enhance the immunosuppressive effect.In a subgroup of acquired aplastic anemia patients whose pathogenesis is associated with genotoxic exposure,the suppressed normal hematopoiesis may result from the bystander insult that is mediated by the soluble inflammatory cytokines generated in response to the immunogenic products of damaged hematopoietic cells in the context of chronic inflammatory state and may offer a protective antineoplastic mechanism against malignant proliferation.

Haploidentical hematopoietic cell transplantation for severe acquired aplastic anemia: a case-control study of post-transplant cyclophosphamide included regimen vs. anti-thymocyte globulin & colony-stimulating factor-based regimen

Dear Editor,Haploidentical allogeneic hematopoietic stem cell transplantation(haplo-HSCT),a curative therapy for severe aplastic anemia(SAA)patients,has been used clinically for decades.Two models,not involving ex vitro T-cell depletion,have been adopted for haplo-HSCT in patients with SAA.The first is referred to as the"Beijing protocol"(Xu et al.,2017),and comprises a conditioning regimen using busulfex(BU),cyclophosphamide(CY).

Outcomes of haploidentical bone marrow transplantation in patients with severe aplastic anemia-II that progressed from non-severe acquired aplastic anemia

Severe aplastic anemia II(SAA-II)progresses from non-severe aplastic anemia(NSAA).The unavailability of efficacious treatment has prompted the need for haploidentical bone marrow transplantation(haplo-BMT)in patients lacking a human leukocyte antigen(HLA)-matched donor.This study aimed to investigate the efficacy of haplo-BMT for patients with SAA-II.Twenty-two patients were included and followed up,and FLU/BU/CY/ATG was used as conditioning regimen.Among these patients,21 were successfully engrafted,19 of whom survived after haplo-BMT.Four patients experienced grade II–IV aGvHD,including two with grade III–IV aGvHD.Six patients experienced chronic GvHD,among whom four were mild and two were moderate.Twelve patients experienced infections during BMT.One was diagnosed with post-transplant lymphoproliferative disorder and one with probable EBV disease,and both recovered after rituximab infusion.Haplo-BMT achieved 3-year overall survival and disease-free survival rate of 86.4%±0.73%after a median follow-up of 42 months,indicating its effectiveness as a salvage therapy.These promising outcomes may support haplo-BMT as an alternative treatment strategy for patients with SAA-II lacking HLA-matched donors.

A comparative study of unrelated donor and matched-sibling donor allogeneic hematopoietic stem cell transplantation in children and adolescents with acquired severe aplastic anemia

Objective To evaluate the efficacy of unrelated do-nor allogeneic hematopoietic stem cell transplantation(URD allo-HSCT).for children and adolescents with severe aplastic anemia(SAA).Methods Clinical data of34 SAA children and adolescents undergoing allo-HSCT were retrospectively analyzed from October 2001 to October 2015.According to the source of donor,the