Comparable Outcomes Between Unrelated and Haploidentical Stem Cell Transplantation in Adult Patients With Severe Aplastic Anemia

Alternative donor transplantation for severe aplastic anemia: a comparative study of the SAAWP EBMT

ABSTRACT

Selecting the most suitable alternative donor becomes challenging in severe aplastic anemia (SAA) when a matched sibling donor (MSD) is unavailable. We compared outcomes in patients with SAA undergoing stem cell transplantation (SCT) from matched unrelated donors (MUD) (n = 1106), mismatched unrelated donors (MMUD) (n = 340), and haploidentical donors (Haplo) (n = 206) registered in the European Society for Blood and Marrow Transplantation database (2012-2021). For Haplo SCT, only those receiving posttransplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis were included. Median age was 20 years, and the median time from diagnosis to transplantation 8.7 months. Compared with MUD, MMUD (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.52-5.6) and Haplo (HR, 5.15; 95% CI, 2.5-10.58) showed significantly higher risks of primary graft failure. MUD had lower rates of acute GVHD compared with MMUD and Haplo (grade 2-4: 13%, 22%, and 19%, respectively; P < .001; grade 3-4: 5%, 9%, and 7%, respectively; P = .028). The 3-year nonrelapse mortality rate was 14% for MUD, 19% for MMUD, and 27% for Haplo (P < .001), whereas overall survival and GVHD and relapse-free survival (GRFS) rates were 81% and 73% for MUD, 74% and 65% for MMUD, and 63% and 54% for Haplo, respectively (P < .001). In addition to donor type, multivariable analysis identified other factors associated with GRFS such as patient age, performance status, and interval between diagnosis and transplantation. For patients with SAA lacking an MSD, our findings support MUDs as the preferable alternative donor option. However, selecting between an MMUD and Haplo donor remains uncertain and requires further exploration.

Exploring strategies to optimise outcomes in hepatitis-associated aplastic anaemia patients following haematopoietic stem cell transplantation

This study aimed to assess haematopoietic stem cell transplantation (HSCT) safety and efficacy while exploring strategies for optimising outcomes in patients with hepatitis-associated aplastic anaemia (HAAA). We retrospectively reviewed 35 HAAA patients who underwent HSCT at a large Chinese blood disease hospital between 2008 and 2022. HAAA patients receiving HSCT typically presented with severe (28.6%) and very severe (65.7%) AA. Male patients predominated (68.6%), with a median onset age of 23 years (range, 9-44). Haploidentical donor-HSCT and matched sibling donor-HSCT were in comparable proportions. The 5-year overall survival (OS) rate was 74.0%, with cumulative incidences of grade II-IV acute and chronic graft-versus-host disease (GVHD) at 37.1% and 22.4%, respectively. A diagnosis-to-HSCT interval ≥ 75 days, acute GVHD, and post-HSCT liver events (e.g., hepatic GVHD and a three-fold increase in aminotransferase or bilirubin) significantly worsened 5-year OS. In the multivariate models, recipients with sex-matched grafts had better OS, and those with younger male donors had a lower incidence of II-IV aGVHD. Higher HLA matching degree (HLA > = 7/10) was an independent prognostic factor associated with better OS and GFFS. A diagnosis-to-HSCT interval ≥ 75 days was predictive of post-transplant liver events in HAAA patients. In conclusion, HSCT was a safe and effective treatment for HAAA. Early transplantation, careful donor selection and improving post-transplant liver events were crucial to optimise outcomes.

Meta-analysis of the results of haploidentical transplantation in the treatment of aplastic anemia

This meta-analysis was to evaluate the outcome of haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) for aplastic anemia (AA) compared with matched related donor (MRD)-HSCT, matched unrelated donor (MUD)-HSCT, and immunosuppressive therapy (IST). Pubmed, Embase, Cochrane Library, Web of Science, CNKI, WanFang, and VIP databases were searched for relevant studies from inception to 22 June 2022. Relative risk (RR) was used to indicate the effect indicator, with a 95% confidence interval (CI) being applied to express the effect size. A subgroup analysis based on the literature quality (low, fair, and high) was applied. Totally, 25 studies were included in this study, comprising 2252 patients. Our findings demonstrated no difference between Haplo-HSCT and MRD-HSCT in 1-, 2-, and 3-year overall survival (OS), failure-free survival (FFS), and engraftment. However, Haplo-HSCT had higher incidences of II-IV acute graft-versus-host disease (aGVHD), chronic GVHD (cGVHD), and cytomegalovirus infection. There were no differences in 3- and 5-year OS, 3-year FFS, platelet engraftment, graft failure (GF), II-IV grade of aGVHD, and complication between Haplo-HSCT and MUD-HSCT; however, Haplo-HSCT had a lower incidence of cGVHD. Compared with IST, Haplo-HSCT had a higher 3-year FFS and 3- and 6-month response rate. However, there were no differences in 3- and 5-year OS, and 12-month response rate between Haplo-HSCT and IST. This study suggests that Haplo-HSCT may be a realistic therapeutic option for AA, which may provide a reference for decision-making.

Acute arrest of hemopoiesis presenting as severe aplastic anemia: a retrospective analysis

OBJECTIVE

The clinical manifestations of acute arrest of hemopoiesis (AAH) are very similar with severe aplastic anemia (SAA). Currently there are no clear diagnostic criteria to distinguish AAH from SAA. Differentiation of AAH from SAA is challenging in the routine clinical practice. This study aimed to analyze the clinical and laboratory features between AAH and SAA patients.

PATIENTS AND METHODS

We performed a retrospective study with cohort of 425 suspected patients who were hospitalized to the First Affiliated Hospital of Zhengzhou University from 1 January 2019 to 31 December 2020. We identified 11 AAH patients and 49 SAA patients to investigate the differentiation diagnostic features.

RESULTS

Clinical and laboratory examinations of 11 patients with AAH met the diagnostic criteria of SAA, and hematopoietic recovery occurred within a median time of 12 (4-21) days. The median time for neutrophils to recover above 1 × 10⁹/L and platelet to recover above 50 × 10⁹/L in all patients with AAH was 5 (3-8) days and 8 (1-13) days, respectively. Compared with the control group SAA, the 11 AAH patients were older, with a median age of 53 (21-69) years old, and their first symptom is usually fever.

CONCLUSIONS

The spontaneous remission of AAH was rapid in most patients, and relapses were rarely observed. With supportive treatment, the AAH patients would show significant improvement on blood routine about a week, otherwise the patients should be treated as early as possible with the SAA regimen.

CMV Infection and CMV-Specific Immune Reconstitution Following Haploidentical Stem Cell Transplantation: An Update

Haploidentical stem cell transplantation (haploSCT) has advanced to a common procedure for treating patients with hematological malignancies and immunodeficiency diseases. However, cure is seriously hampered by cytomegalovirus (CMV) infections and delayed immune reconstitution for the majority of haploidentical transplant recipients compared to HLA-matched stem cell transplantation. Three major approaches, including in vivo T-cell depletion (TCD) using antithymocyte globulin for haploSCT (in vivo TCD-haploSCT), ex vivo TCD using CD34 + positive selection for haploSCT (ex vivo TCD-haploSCT), and T-cell replete haploSCT using posttransplant cyclophosphamide (PTCy-haploSCT), are currently used worldwide. We provide an update on CMV infection and CMV-specific immune recovery in this fast-evolving field. The progress made in cellular immunotherapy of CMV infection after haploSCT is also addressed. Groundwork has been prepared for the creation of personalized avenues to enhance immune reconstitution and decrease the incidence of CMV infection after haploSCT.