Severe aplastic anemia: allogeneic bone marrow transplantation as first-line treatment

The Role of Pre-existing Anti-HLA Antibodies in Severe Aplastic Anemia Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation

The objective is to underscore the significance of pre-existing anti-HLA Abs in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for SAA. A retrospective analysis was conducted using data from 244 SAA patients who underwent allo-HSCT between January 2016 and October 2022. The patient cohort was divided into 2 groups based on the presence of pre-existing anti-HLA Abs. Out of 244 SAA patients, 82 were tested positive for anti-HLA Abs. Seventeen patients were tested with DSA in haplo-HSCT. We found that the presence of pre-existing anti-HLA Abs did not influence neutrophil engraftment (P = .600); however, it resulted in delayed platelet recovery (P = .006). Comparatively, patients with anti-HLA Abs demonstrated lower overall survival (OS) compared to their counter parts without anti-HLA Abs (P = .001), with a correspondingly elevated transplant-related mortality (TRM) in the former group (P = .002). Multivariate analysis established pre-existing anti-HLA Abs as an independent risk factor for impaired platelet recovery (HR 1.67, 95% CI 1.16 to 2.44, P = .006) and OS (HR 2.19, 95% CI 1.03 to 4.67, P = .043). However, there were no differences between DSA and non-DSA patients after desensitization in haplo-HSCT. In summary, the presence of pre-existing anti-HLA Abs in SAA patients undergoing allo-HSCT appears to detrimentally affect platelet recovery and overall prognosis.

Comparison of efficacy of eltrombopag combined with immunosuppression in the treatment of severe aplastic anemia and very severe aplastic anemia: real-world data and evidence

Eltrombopag combined with immunosuppressive therapy (IST) was superior to IST alone for severe aplastic anemia (SAA) in the previous studies. But in China, horse antithymocyte globulin (hATG) is not available, instead, we use rabbit ATG (rATG). Here, we compared the efficacy and safety of IST (rATG combined with cyclosporine) combined with or without eltrombopag for the first-line treatment of SAA and very severe aplastic anemia (VSAA). A total of 371 patients in ten institutions in China from April 1, 2017 to December 1, 2022 were enrolled. The overall response (OR) rate at 3 months (54.2% vs. 41%; P = 0.046), the complete response (CR) (31.3% vs. 19.4%; P = 0.041) and OR (78.3% vs. 51.1%; P < 0.0001) rates at 6 months were significantly higher with IST combined with eltrombopag than with IST alone in SAA patients. While in VSAA patients, the addition of eltrombopag to IST only increased the CR rate at 6 months (29.8% vs. 9.43%; P = 0.010). Liver injury increased significantly in groups treated with IST combined with eltrombopag (P < 0.05). Serious treatment-related toxicities were similar (P > 0.05). In patients with SAA, 3-year failure-free survival (FFS) of eltrombopag combined with IST group was significantly higher than that of IST group (70.7 ± 5.3% vs. 50.3 ± 3.9%; P = 0.007). In patients with VSAA, the addition of eltrombopag significantly improved 3-year overall survival (OS) (82.2 ± 5.7% vs. 57.3 ± 7.2%; P = 0.020). Our findings suggested that IST combined with eltrombopag could improve the hematological recovery of newly diagnosed SAA without increasing severe toxicities. But in VSAA, the addition of eltrombopag seemed to show no other improvement to efficacy except the CR rate at 6 months.

Exploring the potential mechanism of Chinese herbal medicine Fuzi on aplastic anemia based on UHPLC-MS/MS method combined with network pharmacology and molecular docking

To reveal the potential mechanism of the effect of Chinese Herbal Medicine Fuzi on Aplastic anaemia (AA) according to the network pharmacology approach and molecular docking. According to Ultra High Performance Liquid Chromatography Mass Spectrometry (UHPLC-MS/MS), 146 chemical ingredients of Fuzi were obtained. By SwissADME online system analysis, a total of 55 compounds such as Magnoflorine, Scutellarein, Luteolin and Gingerol may be the main active components of Fuzi and 145 common targets related to AA were predicted. 17 targets such as MAPK1, AKT1 and GRB2 were considered as hub targets. KEGG and GO enrichment analysis obtained 122 signalling pathways and 950 remarkable results. These results suggested that Fuzi exerted pharmacological effects on AA mainly by regulating PI3K-Akt, MAPK and JAK-STAT signalling pathways and epithelial cell proliferation, cell differentiation, regulate energy production and other biological processes. Meanwhile, molecular docking results showed that the hub targets had good binding ability with the main active ingredients.

Co-transplantation of umbilical cord mesenchymal stem cells and peripheral blood stem cells in children and adolescents with refractory or relapsed severe aplastic anemia

To evaluate the co-transplantation efficacy of umbilical cord mesenchymal stem cells (UC-MSCs) and peripheral blood stem cells (PBSCs) as a novel approach for refractory or relapsed severe aplastic anemia (R/R SAA) in children and adolescents, thirty-two children and adolescents diagnosed with R/R SAA underwent a retrospective chart review. The patients were categorized into two groups based on the source of PBSCs: the matched sibling donor (MSD) group and the unrelated donor (UD) group. No adverse events related to UC-MSC infusion occurred in any of the patients. The median time for neutrophil engraftment was 13 days (range: 10-23 days), and for platelets, it was 15 days (range: 11-28 days). Acute GVHD of Grade I-II and moderate chronic GVHD were observed in 21.8 and 12.5% of cases, respectively. No statistically significant differences were found between the MSD and UD groups in terms of engraftment, GVHD, and complications, including infection and hemorrhagic cystitis. The median follow-up time was 38.6 months (range: 1.4-140.8 months). As of October 31, 2021, five patients had succumbed, while 27 (84.4%) survived. The 5-year OS rate showed no statistically significant difference between the MSD and UD groups (84.8 ± 10.0 vs. 82.4 ± 9.2%, p = 0.674). In conclusion, the application of UC-MSCs in the treatment of R/R SAA in PBSC transplantation is reliable and safe, they had no graft rejection, low incidence of severe GVHD which may have been contributed by the co-infusion of MSC.

Addition of ruxolitinib to standard graft-versus-host disease prophylaxis for allogeneic stem cell transplantation in aplastic anemia patients

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers rapid hematopoietic and immune reconstitution for aplastic anemia (AA). As a non-malignant disorder, attenuation of GVHD remains a clinical priority in AA patients. Our study sought to investigate the safety and efficacy of the prophylactic use of ruxolitinib in allogeneic HSCT. A total of 35 AA patients were retrospectively consecutively treated with allo-HSCT whereby ruxolitinib was added to the standard GVHD prophylaxis regimen (rux group). The addition of peri-transplant ruxolitinib did not impact the engraftment and graft function, while better recovery of CD4+ Tregs in the rux group was observed. Interestingly, the rux group demonstrated significantly lower incidence of bacterial/fungal infections (17.14% vs 45.71%). Compared to the control group, the rux group exhibited significantly lower incidence of moderate to severe aGVHD (17.1% vs 48.6%) with a trend toward lower severe aGVHD (8.6% vs 20%) and cGVHD (26.2 vs 38.3). The rux group also demonstrated a trend toward higher GVHD and failure-free survival (GFFS: 85.7% vs 68.6%) and lower TRM (2.9% vs 14.3%). Addition of ruxolitinib to standard GVHD prophylaxis regimen, thus, represents a safe and highly efficient method for the attenuation of GVHD with better outcome of allo-HSCT.

Quality of life after immune suppressive therapy in aplastic anemia

Acquired aplastic anemia (AA) is a rare form of immune-mediated bone marrow failure, which can result in life-threatening infections or bleeding if left untreated. Treatment consists of either immune suppressive therapy (IST) or allogeneic stem cell transplantation (alloHSCT). While considerable research has been published regarding survival, response rate and toxicity of both treatments, knowledge on the impact on quality of life (QoL) is scarce. We used the recently developed AA-specific QoL questionnaire (QLQ-AA/PNH-54) to evaluate QoL in a single center cohort of AA patients who were successfully treated with IST. The 54 questions represent 12 different QoL domains. Results were analyzed for all patients and grouped based on hematologic response (complete response (CR) or partial response (PR)). Thirty-six successfully treated adult patients (15 in CR, 21 in PR) completed the questionnaire (median age 54 years, range 21-71; median time since last IST 5 years, range 0-41). Fatigue was experienced by 83% of patients. Even though total QoL scores did not significantly differ between patients with PR and CR (105 vs 92, p-value 0,17) there appeared to be a trend towards higher scores in patients with PR, especially in domains concerning psychological wellbeing. This trend was most clear in the domains fear of progression (2,12 in PR patients vs 1,73 in CR patients; p-value 0,08) and role functioning (2,22 vs 1,88; p-value 0,07). In conclusion, patients with AA continue to experience psychological and physical effects despite successful IST.

The evolution and impact of sarcopenia in severe aplastic anaemia survivors following allogeneic haematopoietic cell transplantation

BACKGROUND

Sarcopenia is a potential risk factor for adverse outcomes in haematopoietic cell transplantation (HSCT) recipients. We aimed to explore longitudinal body changes in muscle and adipose mass and their prognostic value in allogeneic HSCT-treated severe aplastic anaemia (SAA) patients.

METHODS

We retrospectively analysed consecutive SAA patients who underwent allogeneic HSCT between January 2017 and March 2022. Measurements of pectoral muscle and corresponding subcutaneous fat mass were obtained via chest computed tomography at baseline and at 1 month, 3 months, 6 months, and 12 months following HSCT. Sarcopenia was defined as pectoral muscle index (PMI) lower than the sex-specific median at baseline. Changes in body composition over time were evaluated by generalized estimating equations. Cox regression models were used to investigate prognostic factors affecting overall survival (OS) and failure-free survival (FFS). A nomogram was constructed from the Cox regression model for OS.

RESULTS

We included 298 adult SAA patients (including 129 females and 169 males) with a median age of 31 years [interquartile range (IQR), 24-39 years] at baseline. Sarcopenia was present in 148 (148/298, 50%) patients at baseline, 218 (218/285, 76%) patients post-1 month, 209 (209/262, 80%) patients post-3 month, 169 (169/218, 78%) patients post-6 month, and 129 (129/181, 71%) patients post-12 month. A significant decrease in pectoral muscle mass was observed in SAA patients from the time of transplant to 1 year after HSCT, and the greatest reduction occurred in post 1-3 months (P < 0.001). The sarcopenia group exhibited significantly lower 5-year OS (90.6% vs. 100%, log-rank P = 0.039) and 5-year FFS (89.2% vs. 100%, log-rank P = 0.021) than the nonsarcopenia group at baseline. Sarcopenia at baseline (hazard ratio, HR, 6.344; 95% confidence interval, CI: 1.570-25.538; P = 0.01; and HR, 3.275; 95% CI: 1.159-9.252; P = 0.025, respectively) and the delta value of the PMI at 6 months post-transplantation (ΔPMI6) (HR, 0.531; 95% CI: 0.374-0.756; P < 0.001; and HR, 0.666; 95% CI: 0.505-0.879; P = 0.004, respectively) were demonstrated to be independent prognostic factors for OS and FFS in SAA patients undergoing HSCT, and were used to construct the nomogram. The C-index of the nomogram was 0.75, and the calibration plot showed good agreement between the predictions made by the nomogram and actual observations.

CONCLUSIONS

Sarcopenia persists in SAA patients from the time of transplant to the 1-year follow-up after HSCT. Both sarcopenia at baseline and at 6 months following HSCT are associated with poor clinical outcomes, especially in patients with persistent muscle mass loss up to 6 months after transplantation.

The outcome of allogeneic hematopoietic stem cell transplantation among elderly patients with severe aplastic anemia and a predictive model from the Chinese Blood and Marrow Transplant Registry group

Not available.

ABO incompatibility haploidentical peripheral blood stem cell transplantation combined with a single cord blood unit for severe aplastic anemia patients

Objective

To observe the efficacy of haploidentcial peripheral blood stem cell transplantation combined with a single unrelated cord blood unit for severe aplastic anemia patients with donor-recipient ABO incompatibility.

Methods

This was a retrospective cohort study and data of 57 severe aplastic anemia patients underwent haploidentical stem cell transplantation from August 1, 2018 to February 28, 2022 in the First Affiliated Hospital of Xi'an Jiaotong University was retrospectively analyzed. All patients were divided into two groups, the donor-recipient ABO matched group (bone marrow+peripheral blood group) using haploidentical bone marrow and peripheral blood stem cells as grafts, and donor-recipient ABO mismatched group (cord blood+peripheral blood group), using unrelated cord blood and haploidentical peripheral blood stem cells as grafts. The differences of hematopoietic reconstitution, acute and chronic graft-versus-host disease, Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infection, and overall survival between the two groups were compared.

Results

There were 30 cases in cord blood+peripheral blood group and 27 cases in bone marrow+peripheral blood group. One patient in bone marrow+peripheral blood group had primary graft failure, while other patients were successfully implanted. There were no significant differences of neutrophil and platelet recovery rates between two groups. The erythrocyte recovery time of cord blood+peripheral blood group was slower than that of bone marrow+peripheral blood group (p < 0.05). There was no significant difference of the incidence of graft-versus-host disease, CMV, EB virus infection and post-transplant lymphoproliferative disorders between two groups (p > 0.05). The incidence of grade III-IV acute graft-versus-host disease in cord blood+peripheral blood group was higher than that of bone marrow+peripheral blood group (p < 0.05). The incidence of intestinal graft-versus-host disease was higher in minor ABO-mismatched transplantation than that in major ABO-mismatched transplantation (p < 0.05). There was no significant difference of overall survival between two groups (p > 0.05).

Conclusion

These findings suggest that haploidentical peripheral blood stem cell transplantation combined with a single cord blood unit may be an alternative option for severe aplastic anemia patients with donor-recipient ABO incompatibility.

A Review of Key Regulators of Steady-State and Ineffective Erythropoiesis

Erythropoiesis is initiated with the transformation of multipotent hematopoietic stem cells into committed erythroid progenitor cells in the erythroblastic islands of the bone marrow in adults. These cells undergo several stages of differentiation, including erythroblast formation, normoblast formation, and finally, the expulsion of the nucleus to form mature red blood cells. The erythropoietin (EPO) pathway, which is activated by hypoxia, induces stimulation of the erythroid progenitor cells and the promotion of their proliferation and survival as well as maturation and hemoglobin synthesis. The regulation of erythropoiesis is a complex and dynamic interaction of a myriad of factors, such as transcription factors (GATA-1, STAT5), cytokines (IL-3, IL-6, IL-11), iron metabolism and cell cycle regulators. Multiple microRNAs are involved in erythropoiesis, mediating cell growth and development, regulating oxidative stress, erythrocyte maturation and differentiation, hemoglobin synthesis, transferrin function and iron homeostasis. This review aims to explore the physiology of steady-state erythropoiesis and to outline key mechanisms involved in ineffective erythropoiesis linked to anemia, chronic inflammation, stress, and hematological malignancies. Studying aberrations in erythropoiesis in various diseases allows a more in-depth understanding of the heterogeneity within erythroid populations and the development of gene therapies to treat hematological disorders.

The state of the art in the treatment of severe aplastic anemia: immunotherapy and hematopoietic cell transplantation in children and adults

Acquired aplastic anemia (AA) is an immune-mediated bone marrow (BM) failure where marrow disruption is driven by a cytotoxic T-cell-mediated autoimmune attack against hematopoietic stem cells. The key diagnostic challenge in children, but also in adults, is to exclude the possible underlying congenital condition and myelodysplasia. The choice of treatment options, either allogeneic hematopoietic cell transplantation (alloHCT) or immunosuppressive therapy (IST), depends on the patient's age, comorbidities, and access to a suitable donor and effective therapeutic agents. Since 2022, horse antithymocyte globulin (hATG) has been available again in Europe and is recommended for IST as a more effective option than rabbit ATG. Therefore, an update on immunosuppressive strategies is warranted. Despite an improved response to the new immunosuppression protocols with hATG and eltrombopag, some patients are not cured or remain at risk of aplasia relapse or clonal evolution and require postponed alloHCT. The transplantation field has evolved, becoming safer and more accessible. Upfront alloHCT from unrelated donors is becoming a tempting option. With the use of posttransplant cyclophosphamide, haploidentical HCT offers promising outcomes also in AA. In this paper, we present the state of the art in the management of severe AA for pediatric and adult patients based on the available guidelines and recently published studies.

The crucial role of NRF2 in erythropoiesis and anemia: Mechanisms and therapeutic opportunities

The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor crucial in cellular defense against oxidative and electrophilic stresses. Recent research has highlighted the significance of NRF2 in normal erythropoiesis and anemia. NRF2 regulates genes involved in vital aspects of erythroid development, including hemoglobin catabolism, inflammation, and iron homeostasis in erythrocytes. Disrupted NRF2 activity has been implicated in various pathologies involving abnormal erythropoiesis. In this review, we summarize the progress made in understanding the mechanisms of NRF2 activation in erythropoiesis and explore the roles of NRF2 in various types of anemia. This review also discusses the potential of targeting NRF2 as a new therapeutic approach to treat anemia.

Guidelines for the diagnosis and management of adult aplastic anaemia: A British Society for Haematology Guideline

Pancytopenia with hypocellular bone marrow is the hallmark of aplastic anaemia (AA) and the diagnosis is confirmed after careful evaluation, following exclusion of alternate diagnosis including hypoplastic myelodysplastic syndromes. Emerging use of molecular cyto-genomics is helpful in delineating immune mediated AA from inherited bone marrow failures (IBMF). Camitta criteria is used to assess disease severity, which along with age and availability of human leucocyte antigen compatible donor are determinants for therapeutic decisions. Supportive care with blood and platelet transfusion support, along with anti-microbial prophylaxis and prompt management of opportunistic infections remain key throughout the disease course. The standard first-line treatment for newly diagnosed acquired severe/very severe AA patients is horse anti-thymocyte globulin and ciclosporin-based immunosuppressive therapy (IST) with eltrombopag or allogeneic haemopoietic stem cell transplant (HSCT) from a matched sibling donor. Unrelated donor HSCT in adults should be considered after lack of response to IST, and up front for young adults with severe infections and a readily available matched unrelated donor. Management of IBMF, AA in pregnancy and in elderly require special attention. In view of the rarity of AA and complexity of management, appropriate discussion in multidisciplinary meetings and involvement of expert centres is strongly recommended to improve patient outcomes.

Comparable outcomes with low-dose and standard-dose horse anti-thymocyte globulin in the treatment of severe aplastic anemia

BACKGROUND

The standard dose (SD) of horse anti-thymocyte globulin (hATG) ATGAM (Pfizer, USA) or its biosimilar thymogam (Bharat Serum, India) for the treatment of Aplastic Anemia (AA) is 40 mg/kg/day for 4 days in combination with cyclosporine. Data on the impact of hATG dose on long-term outcomes are limited. Here, we describe our comparative experience using 25 mg/kg/day (low-dose [LD]) hATG for 4 days with SD for the treatment of AA.

METHODS

We retrospectively studied patients with AA (age > 12 years) who received two doses of hATG combined with cyclosporine. Among 93 AA patients who received hATG, 62 (66.7%) and 31 (33.3%) patients received LD and SD hATG with cyclosporine, respectively. Among these,seventeen(18.2%) patients also received eltrombopag with hATG and cyclosporine. Overall response rates [complete response (CR) and partial response (PR)] of LD and SD hATG groups at 3 months (50% vs. 48.4%; p = 0.88), 6 months (63.8% vs. 71.4%; p = 0.67), and 12 months (69.6% vs. 79.2%; p = 0.167) were comparable. The mean (Standard Deviation) 5-year Kaplan-Meier estimate of overall survival and event-free survival was 82.1 (4.6)% and 70.9 (5.5)% for the study population. The mean (standard deviation) 5-year Kaplan-Meier estimate of overall survival and event-free survival of those who received LD hATG versus SD hATG dose was 82.9 (5·3)% versus 74.8 (10·3)% (P = 0·439), and 75.2 (6.2)% versus 61.4(11.2)% (P = 0·441).

CONCLUSION

Our study revealed that the response rates of patients with AA and LD were similar to those of patients with SD to hATG combined with cyclosporine in a real-world setting.

Haploidentical Hematopoietic Stem Cell Transplantation for Patients with Severe Aplastic Anemia-Single-Centre Experience

Severe aplastic anemia (SAA) is a life-threatening type of aplastic anemia for which allogeneic stem cell transplantation or immunosuppressive therapy are the principal treatment modalities. Only about 25-30% of patients have a matched sibling donor, and finding an unrelated donor in ethnic minorities is a challenge. The use of related haploidentical donor transplants in severe aplastic anemia is uncommon. We would like to report our experience with the first four patients who underwent haploidentical transplants for severe aplastic anemia. This is a retrospective study. We collected data from our transplant database of all haploidentical hematopoietic stem cell transplants for SAA from 1 January 2020 to 31 December 2021. The transplant protocol used was the Hopkins' protocol. There were three patients who underwent haploidentical transplants as primary therapy for SAA. A fourth patient received a haploidentical transplant after immunosuppressive therapy failure. The median age of the patients at transplant was 24 y (range 20-29). All patients were engrafted. Neutrophil engraftment occurred at a median of 21 days (range 17-22). Any active infections resolved with the recovery of blood counts. The median hospitalization time was 27 days (range 22-41). Only one patient had grade 2 acute GVHD involving the skin. There was no chronic GVHD. All patients had complete lymphoid and myeloid donor chimerism on day 60. Based on our experience and the emerging literature, haplo-identical transplantation should be considered for select young patients with SAA who have low chances of responding to immunosuppressive therapy.

Comparison of Stem Cell Transplantation Using Unrelated, Haploidentical, and Sibling Donors for Patients with Acquired Severe Aplastic Anemia: A Single-Center Retrospective Cohort Study

The preferred donor (haploidentical donor [HID] versus matched unrelated donor [URD]) choice in patients with acquired severe aplastic anemia (SAA) who lack an HLA-matched sibling donor (MSD) and fail upfront immunosuppressive treatment (IST) therapy is unknown. We retrospectively investigated SAA patients (n = 58) who underwent allogeneic stem cell transplantation (allo-SCT) between January 2012 and October 2022. The 5-year overall survival (OS) and 5-year failure-free survival (FFS) were comparable among the URD (n = 8), HID (n = 25), and MSD (n = 25) cohorts (OS: mean, 87.5 ± 11.7% versus 98.0 ± 6.5% versus 83.3 ± 7.6% [P = .926]; FFS: mean, 60.0 ± 18.2% versus 87.0 ± 7.0% versus 78.3 ± 8.6% [P = .222]). Multivariate analysis revealed that primary engraftment failure independently predicted OS and secondary graft failure predicted FFS among SAA patients who underwent allo-SCT, but donor type and age were not predictive of these outcomes. An urgent second SCT for patients with engraftment failure may be an effective salvage treatment. Our findings show that an alternative donor SCT is indicated for eligible SAA patients without an MSD even if age ≥40 years.

Conditional survival and standardized mortality ratios of patients with severe aplastic anemia surviving at least one year after hematopoietic cell transplantation or immunosuppressive therapy

Immunosuppressive treatment (IST) and hematopoietic cell transplant (HCT) are standard therapies for severe aplastic anemia (SAA). We report on conditional survival and standardized mortality ratios (SMR), which compare the mortality risk with the general population adjusted for age, gender, and race/ethnicity, in patients with SAA alive for at least 12 months after treatment with IST or HCT between 2000 and 2018. Given changes to treatment regimens and differences in length of follow-up, two treatment periods were defined a priori: 2000-2010 and 2011-2018. The SMR of patients treated during the period 2000-2010 and who survived one year were 3.50 (95% confidence interval [CI]: 2.62-4.58), 4.12 (95% CI: 3.20-5.21), and 8.62 (95% CI: 6.88-10.67) after IST, matched related donor HCT, and alternative donor HCT, respectively. For the period 2011-2018, the corresponding SMR were 2.89 (95% CI: 1.54-4.94), 3.12 (95% CI: 1.90-4.82), and 4.75 (95% CI: 3.45-6.38), respectively. For IST patients, their mortality risk decreased over time, and became comparable to the general population by five years. For patients who underwent HCT during 2000-2010 and 2011-2018, their mortality risk became comparable to the general population after ten years and after five years, respectively. Thus, 1-year survivors after IST or HCT can expect their longevity beyond five years to be comparable to that of the general US population.

Small volume bone marrow aspirates with high progenitor cell concentrations maximize cell therapy dose manufacture and substantially reduce donor hemoglobin loss

BACKGROUND

Bone marrow (BM) transplantation is a life-saving therapy for hematological diseases, and the BM harbors also highly useful (progenitor) cell types for novel cell therapies manufacture. Yet, the BM collection technique is not standardized.

METHODS

Benchmarking our collection efficiency to BM collections worldwide (N = 1248), we noted a great variability of total nucleated cell (TNC) yields in BM products (HPC-M) with superior performance of our center, where we have implemented a small volume aspirate policy. Thus, we next prospectively aimed to assess the impact of BM collection technique on HPC-M quality. For each BM collection (N = 20 donors), small volume (3 mL) and large volume (10 mL) BM aspirates were sampled at 3 time points and analyzed for cell composition.

RESULTS

Compared to large volume aspirates, small volume aspirates concentrated more TNCs, immune cells, platelets, hematopoietic stem/progenitor cells, mesenchymal stromal cells (MSCs), and endothelial progenitors. Inversely, the hemoglobin concentration was higher in large volume aspirates indicating more hemoglobin loss. Manufacturing and dosing scenarios showed that small volume aspirates save up to 42% BM volume and 44% hemoglobin for HPC-M donors. Moreover, MSC production efficiency can be increased by more than 150%.

CONCLUSIONS

We propose to consider small volume BM aspiration as standard technique for BM collection.

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.

Graft-versus-host disease and relapse/rejection-free survival after allogeneic transplantation for idiopathic severe aplastic anemia: a comprehensive analysis from the SAAWP of the EBMT

Survival after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe idiopathic aplastic anemia (SAA) has improved in recent years, approaching 75% at 5 years. However, an SAA-adapted composite endpoint, graft-versus-host disease (GvHD) and relapse/rejection-free survival (GRFS), may more accurately assess patient outcomes beyond survival. We analyzed GRFS to identify risk factors and specific causes of GRFS failure. Our retrospective analysis from the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation included 479 patients with idiopathic SAA who underwent allo-HSCT in two conventional situations: i) upfront allo-HSCT from a matched related donor (MRD) (upfront cohort), and ii) allo-HSCT for relapsed or refractory SAA (rel/ref cohort). Relevant events for GRFS calculation included graft failure, grade 3-4 acute GvHD, extensive chronic GvHD, and death. In the upfront cohort (n=209), 5-year GRFS was 77%. Late allo-HSCT (i.e., >6 months after SAA diagnosis) was the main poor prognostic factor, specifically increasing the risk of death as the cause of GRFS failure (hazard ratio [HR]=4.08; 95% confidence interval [CI]: 1.41-11.83; P=0.010). In the rel/ref cohort (n=270), 5-year GRFS was 61%. Age was the main factor significantly increasing the risk of death (HR=1.04; 95% CI: 1.02-1.06; P<0.001), acute GvHD (HR=1.03; 95% CI: 1.00-1.07; P=0.041), and chronic GvHD (HR=1.04; 95% CI: 1.01-1.08; P=0.032) as the cause of GRFS failure. GRFS after upfront MRD allo-HSCT was very good, notably with early allo-HSCT, confirming that younger patients with an MRD should be transplanted immediately. GRFS was worse in cases of salvage allo-HSCT, most notably in older patients, questioning the utility of allo-HSCT earlier in the disease course.

Prognostic Impact of Quantifying Sarcopenia and Adipopenia by Chest CT in Severe Aplastic Anemia Patients Treated With Allogeneic Hematopoietic Stem Cell Transplantation

RATIONALE AND OBJECTIVES

To investigate the prognostic role of chest CT-defined sarcopenia and adipopenia in severe aplastic anemia (SAA) patients treated with hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

This was a retrospective study of 123 consecutive SAA patients treated with HSCT. CT imaging was performed to quantify the pectoralis muscle (including major and minor) index (PMI) and the corresponding subcutaneous adipose tissue index (SAI). Sarcopenia and adipopenia were defined as PMI and SAI lower than the respective sex-specific medians. Correlations of the PMI and SAI with anthropometric indexes were calculated. Transplant-related outcomes were compared between the sarcopenia and adipopenia groups. Prognostic factors for overall survival (OS) and fail-free survival (FFS) were identified by Cox regression and were used to create a nomogram. The accuracy of the nomogram was evaluated by ROC curves.

RESULTS

PMI showed good correlation with BMI and fat-free mass index (p < 0.001). SAI correlated with BMI and fat mass index (p < 0.001). The sarcopenia group (47.2%) had a significantly worse 3-year OS (90.8% vs. 77.6%, p = 0.045) and 3-year FFS (89.2% vs. 74.1%, p = 0.035) than the nonsarcopenia group. Sarcopenia status and diagnostic category were used to construct the nomogram of OS, as these were independent prognostic factors in the multivariate analysis for OS and FFS (p < 0.05). The area under the curve of the nomogram at one year and three years was 0.801 and 0.721, respectively.

CONCLUSION

Sarcopenia indicates a poor prognosis in SAA patients undergoing HSCT. Intensive supportive care is suggested for SAA patients with sarcopenia before transplantation.

Busulfan for Allogeneic Hematopoietic Stem Cell Transplantation in Children with Severe Aplastic Anemia: A Retrospective Study

INTRODUCTION

This retrospective study aimed to compare a range of conditioning regimens in children with severe aplastic anemia (SAA) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the Seventh Medical Center of PLA General Hospital between January 2008 and June 2017.

METHODS

Patients were categorized into the Bu (Bu + Flu + Cy + ATG-F regimen) and control (Flu + Cy + ATG-F) groups, with a median follow-up time after HSCT of 3.5 (range, 3.1-6.2) and 3.7 (3.2-5.9) years in the Bu and control groups, respectively.

RESULTS

No differences were observed between the two groups regarding the median time of peripheral blood neutrophil and platelet engraftment (p = 0.538 and p = 0.491); the 28-day engraftment rates of neutrophils were similar (p = 0.199), although higher for platelets with Bu (p = 0.044). Additionally, graft failure was 0% and 20.0% in the Bu and control groups, respectively (p = 0.004). In both groups, the incidence of grades III-IV (or grades II-IV) acute graft-versus-host disease (GVHD) and chronic GVHD was not significantly different (p > 0.05). Moreover, the 3-year overall survival and failure-free survival did not show significant differences (p = 0.670 and p = 0.908).

DISCUSSION

In children with SAA undergoing allo-HSCT, conditioning regimen with Bu + Flu + Cy + ATG-F is capable of enhancing the myeloablation effect, promoting donor hematopoietic stem cell engraftment, and reducing the graft failure rate. Furthermore, it does not increase the incidence of complications, including GVHD.

Transfusion-dependent non-severe aplastic anemia: characteristics and outcomes in the clinic

Transfusion-dependent non-severe aplastic anemia (TD-NSAA) is a rare condition of bone marrow failure that can persist for a long time or develop into severe aplastic anemia (SAA). Little is known about the clinical and laboratory characteristics, and disease prognosis and outcomes in TD-NSAA patients. The clinical and laboratory data of 124 consecutive TD-NSAA patients in the Chinese Eastern Collaboration Group of Anemia from December 2013 and January 2017 were analyzed retrospectively. In 124 TD-NSAA patients, the median age was 32 years (range: 3-80) and the median disease course was 38 months (range: 3-363). Common complications were iron overload (53/101, 52.5%), liver and kidney dysfunction (42/124, 33.9%), diabetes mellitus/impaired glucose tolerance (24/124, 19.4%), and severe infection (29 cases, 23.4%). 58% of patients (57/124) developed severe aplastic anemia with a median progression time of 24 months (range: 3-216). Patients with absolute neutrophil count (ANC) <0.5×10⁹/L, severe infection, or iron overload had a higher probability of progression to SAA (P=0.022, P=0.025, P=0.001). Patients receiving antithymocyte globulin (ATG) plus Cyclosporin A (CsA) had a higher overall response rate compared to those receiving CsA alone (56.7% vs 19.3%, P < 0.001). The addition of ATG was the favorable factor for efficacy (P=0.003). Fourteen patients developed secondary clonal hematologic disease: eleven patients with paroxysmal nocturnal hemoglobinuria, two patients with myelodysplastic syndromes, and one patient with acute myeloid leukemia, respectively. Ten patients (8.1%) died with a median follow-up of 12 months (range: 3- 36 months). Patients with TD-NSAA usually have a prolonged course of disease, and are prone to be complicated with important organ damage and disease progression to SAA. Intensive immunosuppressive therapy based on ATG might be an appropriate approach for TD-NSAA. Clinical trial registration: http://www.chictr.org.cn/edit.aspx?pid=125480&htm=4, identifier ChiCTR2100045895.

Optimizing a fully automated and closed system process for red blood cell reduction of human bone marrow products

BACKGROUND AIMS

Hematopoietic stem cell transplantation using bone marrow as the graft source is a common treatment for hematopoietic malignancies and disorders. For allogeneic transplants, processing of bone marrow requires the depletion of ABO-mismatched red blood cells (RBCs) to avoid transfusion reactions. Here the authors tested the use of an automated closed system for depleting RBCs from bone marrow and compared the results to a semi-automated platform that is more commonly used in transplant centers today. The authors found that fully automated processing using the Sepax instrument (Cytiva, Marlborough, MA, USA) resulted in depletion of RBCs and total mononuclear cell recovery that were comparable to that achieved with the COBE 2991 (Terumo BCT, Lakewood, CO, USA) semi-automated process.

METHODS

The authors optimized the fully automated and closed Sepax SmartRedux (Cytiva) protocol. Three reduction folds (10×, 12× and 15×) were tested on the Sepax. Each run was compared with the standard processing performed in the authors' center on the COBE 2991. Given that bone marrow is difficult to acquire for these purposes, the authors opted to create a surrogate that is more easily obtainable, which consisted of cryopreserved peripheral blood stem cells that were thawed and mixed with RBCs and supplemented with Plasma-Lyte A (Baxter, Deerfield, IL, USA) and 4% human serum albumin (Baxalta, Westlake Village, CA, USA). This "bone marrow-like" product was split into two starting products of approximately 600 mL, and these were loaded onto the COBE and Sepax for direct comparison testing. Samples were taken from the final products for cell counts and flow cytometry. The authors also tested a 10× Sepax reduction using human bone marrow supplemented with human liquid plasma and RBCs.

RESULTS

RBC reduction increased as the Sepax reduction rate increased, with an average of 86.06% (range of 70.85-96.39%) in the 10×, 98.80% (range of 98.1-99.5%) in the 12× and 98.89% (range of 98.80-98.89%) in the 15×. The reduction rate on the COBE ranged an average of 69.0-93.15%. However, white blood cell (WBC) recovery decreased as the Sepax reduction rate increased, with an average of 47.65% (range of 38.9-62.35%) in the 10×, 14.56% (range of 14.34-14.78%) in the 12× and 27.97% (range of 24.7-31.23%) in the 15×. COBE WBC recovery ranged an average of 53.17-76.12%. Testing a supplemented human bone marrow sample using a 10× Sepax reduction resulted in an average RBC reduction of 84.22% (range of 84.0-84.36%) and WBC recovery of 43.37% (range of 37.48-49.26%). Flow cytometry analysis also showed that 10× Sepax reduction resulted in higher purity and better recovery of CD34+, CD3+ and CD19+ cells compared with 12× and 15× reduction. Therefore, a 10× reduction rate was selected for the Sepax process.

CONCLUSIONS

The fully automated and closed SmartRedux program on the Sepax was shown to be effective at reducing RBCs from "bone marrow-like" products and a supplemented bone marrow product using a 10× reduction rate.

How I diagnose and treat acute graft-versus-host disease after solid organ transplantation

Acute graft-versus-host disease (GVHD) is a rare complication after solid organ transplantation (SOT) that carries high mortality. Caused by immunocompetent donor leukocytes within the transplanted organ, which become activated against recipient tissues, GVHD typically develops 2 to 12 weeks after SOT and can affect the skin, gastrointestinal tract, liver, and bone marrow. Signs and symptoms are nonspecific and include a rash, nausea, appetite loss, diarrhea, and cytopenias. Pancytopenia from marrow-directed GVHD is the primary driver of mortality. The diagnosis of GVHD is often delayed but should be confirmed by biopsy of an affected organ. Evidence of donor chimerism in blood or marrow supports the diagnosis. When GVHD is diagnosed we initiate treatment with systemic corticosteroids. At that time, if GVHD only involves skin or oral mucosa we also decrease maintenance immunosuppression levels to allow the recipient to reject the donor immune cells. For GVHD involving the marrow we initiate an allogeneic hematopoietic cell donor search early. In this article, we describe 3 cases of GVHD after SOT, outline our approach to diagnosis and management, and then provide analysis of the 3 instructive cases.

Feasibility of thoracic CT in assessing anemia for aplastic anemia patients undergoing allogeneic hematopoietic stem cell transplantation

BACKGROUND

Anemia is an important clinical symptom for aplastic anemia (AA) patients who are suffered with peripheral pancytopenia.

OBJECTIVE

To evaluate the accuracy of diagnosing anemia with non-invasive chest computed tomography (CT) for AA patients.

METHODS

The CT attenuation of left ventricular (LV) cavity and interventricular septum (IVS) on unenhanced thoracic CT images of AA patients are retrospectively analyzed, including 84 AA patients in pre-transplant and 1-month (n = 82), 2-month (n = 72), 3-month (n = 75), 6-month (n = 74) and 12-month (n = 70) followed patients in post-transplant. The difference (IVS-LV) and ratio (LV/IVS) of the CT attenuation between LV cavity and interventricular septum are calculated. Serum hemoglobin is estimated within 24 hours of CT imaging. The CT attenuations of IVS-LV and LV/IVS are correlated with hemoglobin, and their variation tendency is analyzed during the treatment of a-HSCT. A receiver operating characteristic (ROC) curve analysis is then performed for the diagnosis of anemia.

RESULTS

The CT attenuations of IVS-LV and LV/IVS well correlate with hemoglobin (r = -0.618 and 0.628, respectively, P <  0.001). The variation tendency of IVS-LV and LV/IVS is similar to that of hemoglobin with opposite directions during one-year follow-up of a-HSCT. When a threshold of CT attenuation of IVS-LV and LV/IVS is set at 11.5HU and 0.77, respectively, both the sensitivity and specificity in diagnosing anemia are good (74.7% and 73.8% in CT attenuation of IVS-LV; 77.4% and 70.4% in LV/LVS, respectively).

CONCLUSIONS

Both CT attenuation of LV/IVS and IVS-LV had similar accuracy in diagnosing anemia for AA patients. The non-invasive chest CT can offer a new possibility to complementarily evaluate anemia for AA patients in the diagnostic radiology reports.

Whole-exome sequencing identifies FANC heterozygous germline mutation as an adverse factor for immunosuppressive therapy in Chinese aplastic anemia patients aged 40 or younger: a single-center retrospective study

Acquired aplastic anemia (AA) is a bone marrow failure disorder characterized by pancytopenia, and immunosuppressive therapy (IST) is the optional first-line management. Several studies identified the influencing factors on IST response; however, there are still a considerable number of patients suffering from poor prognoses. In this study, we enrolled 61 AA patients aged ≤ 40 years old, and whole-exome sequencing (WES) found unexpected high FANC heterozygous germline mutations (28/61, 45.9%). Patients with FANC mutations have a significantly lower absolute reticulocyte count and CD34⁺ % in the bone marrow and also lower 3-, 6-, and 9-month IST response than that without mutation, which were 0% vs. 25% (P = 0.017), 26.3% vs. 42.1% (P = 0.495), and 29.4% vs. 72.2% (P = 0.011), especially in anti-thymocyte globulin combined with the cyclosporin A (ATG + CsA) group, which were 0% vs.33.4% (P = 0.143), 25% vs.83.3% (P = 0.103), and 25% vs. 100% (P = 0.003), respectively. The event-free survival in the FANC^wt group was also better than that in the FANC^mut group (P = 0.016) and also showed in patients who received ATG + CsA treatment (P = 0.045). In addition, all the adverse effects of FANC germline mutation were not significant in stem cell-transplanted group. Our result indicated that the WES-based detection of FANC heterozygous germline mutations may have a great meaning in predicting IST response of acquired AA. This study was registered at chictr.org.cn (# ChiCTR2100054992).

Avatrombopag is effective in patients with chemoradiotherapy-induced aplastic anemia: a single-center, retrospective study

Aplastic anemia (AA) secondary to radiotherapy presents a difficult situation in the treatment of both the malignant tumor and AA itself. We aimed to evaluate the efficacy of avatrombopag (AVA), a thrombopoietin receptor agonist, in patients with AA secondary to chemoradiotherapy. In this retrospective study, patients with malignant tumors who were diagnosed with AA after radiotherapy and chemotherapy and accepted AVA between September 2020 and October 2021 at Peking Union Medical College Hospital were selected. A total of 34 patients were enrolled, including 13 (38.2%) men, with a median age of 60 (20-71) years. At a median of 8 (6-18) months of follow-up, the overall response rates (ORRs) at 1, 3, and 6 months were 32.4%, 55.9%, and 58.8%, respectively, and the complete response rates (CRRs) were 5.9%, 14.7%, and 23.5%, respectively. The median time to respond was 3 (1-6) months. In total, 15.0% of patients relapsed during follow-up, but no clonal evolution was noticed. Mild side effects were observed in 17.6% of patients without drug withdrawal. At the end of follow-up, 17.6% of patients had tumors relapsed. Four patients died, three from tumor relapse and one from cerebral hemorrhage. The ORR and CRR did not correlate with eltrombopag before AVA (p > 0.05) but increased when the total exposure of AVA increased (p = 0.011), and the threshold for AVA response was a cumulative dose > 3,000 mg (p = 0.013). AVA yielded good response and tolerance in patients treated for AA secondary to chemoradiotherapy, and a higher dose may correlate with better response.

Comparable long-term outcomes between upfront haploidentical and identical sibling donor transplant in aplastic anemia: a national registry-based study

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a curative option for severe aplastic anemia (SAA), and transplantation from identical sibling donors (ISD) has been recommended as a first-line treatment. Haploidentical donor (HID) transplantation for SAA has made great advances; thus, an increased role of HID-SCT in SAA should be considered. We performed a national registry-based analysis comparing long-term outcomes in the upfront HID or upfront ISD SCT setting. A total of 342 SAA patients were enrolled, with 183 patients receiving HID SCT and 159 receiving ISD SCT. The estimated 9-year overall survival and failure-free survival were 87.1±2.5% and 89.3±3.7% (P=0.173) and 86.5±2.6% versus 88.1±3.8% (P=0.257) for patients in the HID and ISD SCT groups, respectively. Transplantation from HID or ISD SCT has greatly improved quality of life (QoL) levels post-HSCT compared to pre-HSCT. The occurrence of chronic graft-versus-host disease was the only identified adverse factor affecting each subscale of QoL. Physical and mental component summaries in adults as well as physical, mental, social, and role well-being in children were all similar between HID and ISD SCT at 5-year time points. At the last follow-up, the proportion of returning to society was comparable between the HID and ISD groups, showing 78.0% versus 84.6% among children and 74.6% versus 81.2% among adults. These data suggest that haploidentical transplant can be considered a potential therapeutic option in the upfront setting for SAA patients in the absence of an HLA-identical related or unrelated donor.

Aplastic anemia and paroxysmal nocturnal hemoglobinuria in children and adults in two centers of Northern Greece

Bone marrow failure (BMF) syndromes are a group of various hematological diseases with cytopenia as a main common characteristic. Given their rarity and continuous progress in the field, we aim to provide data considering the efficiency and safety of the therapeutic methods, focusing on the treatment of aplastic anemia(AA) and paroxysmal nocturnal hemoglobinuria (PNH). We enrolled consecutive patients diagnosed with BMF in two referral centers of Northern Greece from 2008 to 2020. We studied 43 patients with AA (37 adults and 6 children/adolescents) and 6 with classical PNH. Regarding classical PNH, 4 patients have received eculizumab treatment with 1/4 presenting extravascular hemolysis. Among 43 patients with aplastic anemia, PNH clones were detected in 11. Regarding patients that did not receive alloHCT (n=15), 14/15 were treated with ATG and cyclosporine as first line, with the addition of eltrombopag in patients treated after its approval (n=9). With a median follow-up of 16.7 (1.8-56.2) months from diagnosis, 12/14 (85.7%) are alive (4-year OS: 85.1%). AlloHCT was performed in 28 patients. Five patients developed TA-TMA which did not resolve in 3/5 (all with a pre-transplant PNH clone). With the follow-up among survivors reaching 86.3 (6.3-262.4) months, 10-year OS was 56.9%, independently associated with PNH clones after adjusting for age (p=0.024). In conclusion, our real-world experience confirms that novel treatments are changing the field of BMF syndromes. Nevertheless, there is still an unmet need to personalize algorithms in this field.

Unrelated umbilical cord blood can improve the prognosis of haploidentical hematopoietic stem cell transplantation

Background

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is widely used as a curative treatment strategy for most types of hematological diseases. However, strategies for enhancing the graft versus leukemia (GVL) effect without aggravating the graft versus host disease (GVHD) effect are still being pursued.

Methods

A retrospective cohort study was performed to compare the outcomes between combined unrelated umbilical cord blood (UCB-haplo HSCT) and haplo HSCT.

Results

The results showed that neither acute GVHD (aGVHD) nor chronic GVHD (cGVHD) was increased in the UCB-haplo HSCT group, and the engraftment and infection rates were similar between the two groups. However, overall survival and progression-free survival were significantly improved, while transplantation-related mortality and relapse were significantly decreased in the UCB-haplo HSCT group by both univariate and multivariate analyses.

Conclusion

Our results indicated that the addition of a UCB unit could improve the prognosis of haplo-HSCT and enhance the GVL effect without increasing the incidence of GVHD.

Trial registration

The cohort study was retrospectively registered at https://www.chictr.org.cn as ChiCTR2100046681.

Long-term follow-up of haploidentical transplantation in relapsed/refractory severe aplastic anemia: a multicenter prospective study

In recent decades, haploidentical stem cell transplantation (haplo-SCT) to treat severe aplastic anemia (SAA) has achieved remarkable progress. However, long-term results are still lacking. We conducted a multicenter prospective study involving SAA patients who underwent haplo-SCT as salvage therapy. Long-term outcomes were assessed, mainly focusing on survival and quality of life (QoL). Longitudinal QoL was prospectively evaluated during pretransplantation and at 3 and 5 years posttransplantation using the SF-36 scale in adults and the PedsQL 4.0 scale in children. A total of 287 SAA patients were enrolled, and the median follow-up was 4.56 years (range, 3.01-9.05 years) among surviving patients. During the long-term follow-up, 268 of 275 evaluable patients (97.5%) obtained sustained full donor chimerism, and 93.4% had complete hematopoietic recovery. The estimated overall survival and failure-free survival for the whole cohort at 9 years were 85.4% ± 2.1% and 84.0% ± 2.2%, respectively. Age (≥18 years) and a poorer performance status (ECOG >1) were identified as risk factors for survival outcomes. For QoL recovery after haplo-SCT, we found that QoL progressively improved from pretransplantation to the 3-year and 5-year time points with statistical significance. The occurrence of chronic graft versus host disease was a risk factor predicting poorer QoL scores in both the child and adult cohorts. At the last follow-up, 74.0% of children and 72.9% of adults returned to normal school or work. These inspiring long-term outcomes suggest that salvage transplantation with haploidentical donors can be routine practice for SAA patients without human leukocyte antigen (HLA)-matched donors.

Comparisons Between modified PTCY and G-CSF/ATG Regimens for Haploidentical Transplantation in Patients with Aplastic Anemia

BACKGROUND

Haploidentical transplantation has become an alternative treatment option for aplastic anemia patients without matched sibling donors or matched unrelated donors. Recently, the post-transplantation cyclophosphamide (PTCY) regimen and granulocyte colony-stimulating factor (G-CSF)/antithymocyte globulin (ATG) regimen have become the most common protocols used worldwide.

OBJECTIVE

We designed this retrospective study to compare the outcomes of patients receiving a modified post-transplantation cyclophosphamide (mPTCY) regimen versus the G-CSF/ATG regimen.

STUDY DESIGN

We retrospectively reviewed and analyzed the clinical data of 130 aplastic anemia patients who underwent haplo-HSCT and received the mPTCY regimen (n=55) or G-CSF/ATG regimen (n=75) between Jan 2013 and Jun 2021 across seven transplant centers.

RESULTS

Neutrophil engraftment was successful in all patients within 30 days in the G-CSF/ATG group. The cumulative neutrophil engraftment rate in the mPTCY group was 96.36% (95% CI, 94.57-97.57, P=0.010). The median time of neutrophil engraftment in the G-CSF/ATG group was 10 (7-28) days, which was more rapid than that observed in the mPTCY group (P <0.001). There were no significant differences in the incidence of graft versus host disease (GVHD) between the two groups. The cumulative incidence of II-IV acute GVHD was 18.40% (95% CI, 4.27-40.31) in the mPTCY group and 19.32% (95% CI, 5.86-38.58) in the G-CSF/ATG group, while the cumulative incidence of III-IV acute GVHD was 7.31% (95% CI, 0.09-37.48) in the mPTCY group and 7.57% (95% CI, 0.20-34.19) in the G-CSF/ATG group. Similarly, no significant difference was observed between the two groups in terms of overall survival (OS), failure-free survival (FFS), and GVHD relapse-free survival (GRFS). The 2-year OS, FFS and GRFS rates were 95.91% (95% CI, 84.59-98.96), 92.25% (95% CI, 80.59-97.03) and 86.68% (95% CI, 73.98-93.44), respectively, in the mPTCY group and 86.67% (95% CI, 76.64-92.59), 81.28% (95% CI, 70.45-88.46) and 77.20% (95% CI, 65.89-85.16), respectively, in the G-CSF/ATG group. The transplantation-related mortality (TRM) rate was significantly higher in the G-CSG/ATG group than in the mPTCY group (13.33% in the G-CSG/ATG group versus 1.96% in the mPTCY group, P=0.022). In multivariate analysis, female donors, a higher hematopoietic cell transplantation comorbidity index (HCT-CI) and III-IV aGVHD were associated with worse survival outcomes.

CONCLUSIONS

In conclusion, the mPTCY and G-CSF/ATG regimens led to similar outcomes in AA patients, but quicker engraftment was observed with the ATG/G-CSF regimen, and a lower incidence of TRM was observed with the mPTCY regimen.

Comparison of Hematopoietic Stem Cell Transplantation Outcomes Using Matched Sibling Donors, Haploidentical Donors, and Immunosuppressive Therapy for Patients With Acquired Aplastic Anemia

We retrospectively compared the outcomes of 387 consecutive patients with acquired aplastic anemia (AA) who underwent hematopoietic stem cell transplantation (HSCT) with a fludarabine-based conditioning regimen from matched sibling donors (MSD) (n = 108) or haploidentical donors (HID) (n = 91) and immunosuppressive therapy (IST) (n = 188) from 2014 to 2020 at our hospital. Compared with HID-HSCT, MSD-HSCT had a lower incidence of graft failure (1% vs. 7%, p = 0.062), grade II–IV acute graft versus host disease (aGvHD) (16% vs. 35%, p = 0.001), and mild to severe chronic GvHD (cGvHD) (8% vs. 23%, p = 0.007), but an equivalent incidence of grade III–IV aGvHD (8% vs. 12%, p = 0.237) and moderate to severe cGvHD (3% vs. 9%, p = 0.076). HSCT had superior blood count recovery at 3, 6, and 12 months compared with IST (p < 0.001). The estimated 5-year overall survival (OS) of the MSD, HID, and IST groups were 86%, 72%, and 79% (p = 0.02), respectively; accordingly, the failure-free survival (FFS) rates were 85%, 68%, and 56%, respectively (p < 0.001). For patients aged ≤40 years, the OS rate was still significantly superior for MSD-HSCT receipients compared to HID-HSCT receipients (89% vs. 76%, p = 0.024) while the HID-HSCT recipients showed similar OS (76% vs. 78%, p = 0.166) but superior FFS (p = 0.047) when follow-up was longer than 14.5 months in contrast to IST. In a multivariate analysis, HID-HSCT and a conditioning regimen that included busulfan were adversely related to OS among patients who received allografts. In conclusion, MSD-HSCT was the frontline choice for patients with severe AA aged ≤40 years, while HID-HSCT was as effective as IST for patients without an MSD.

Comparable Outcomes in Acquired Severe Aplastic Anemia Patients With Haploidentical Donor or Matched Related Donor Transplantation: A Retrospective Single-Center Experience

Clinical data of patients with severe aplastic anemia (SAA) were retrospectively analyzed to evaluate the outcomes of haploidentical hematopoietic stem cell transplantation (HID-HSCT) with matched related sibling hematopoietic stem cell transplantation (MSD-HSCT) in complications and survivals. Thirty consecutive patients were enrolled in the study with a median follow-up of 50 months (range 4, 141), and the median age of the patients was 21 years (range 3, 49). All the patients achieved myeloid engraftment in the two cohorts. The cumulative incidences of platelet engraftment were 95.5 and 100% in HID cohort and MSD cohort, respectively. The median time for neutrophil and platelet recovery was 11 (range 9, 19) and 15 (range 10, 25) days in HID cohort, and 12 (range 10, 19) and 14 (range 8, 25) days in MSD cohort. The cumulative incidences of grade II–IV and grade III–IV acute graft vs. host disease (aGvHD) in HID cohort and in MSD cohort were 18.9 vs. 14.3% (p = 0.77) and 10.5 vs. 0% (p = 0.42), respectively. The cumulative incidences of chronic graft vs. host disease (cGvHD) was 22.7% in HID cohort and 25.5% in MSD cohort (p = 0.868). The 5-year overall survival (OS) rates and 5-year failure-free survival (FFS) rates in HID cohort and MSD cohort were 85.1 vs. 87.5% (p = 0.858), 80.3 vs. 87.5% (p = 0.635), respectively. The median time to achieve engraftment, cumulative incidence of aGvHD and cGvHD, and the 5-year OS and FFS rates were not significantly different between the two cohorts. We suggest that HID-HSCT might be a safety and effective option for SAA patients without a matched donor.

Development and validation of a mortality predicting scoring system for severe aplastic anaemia patients receiving haploidentical allogeneic transplantation

Haploidentical allogeneic haematopoietic stem cell transplantation (haplo-HSCT) is a significant alternative treatment for severe aplastic anaemia (SAA). To improve this process by modifying the risk stratification system, we conducted a retrospective study using our database. 432 SAA patients who received haplo-HSCT between 2006 and 2020 were enrolled. These patients were divided into a training (n = 288) and a validation (n = 144) subset randomly. In the training cohort, longer time from diagnosis to transplantation, poorer Eastern Cooperative Oncology Group (ECOG) status and higher haematopoietic cell transplantation-specific comorbidity index (HCT-CI) score were independent risk factors for worse treatment-related mortality (TRM) in the final multivariable model. The haplo-HSCT scoring system was developed by these three parameters. Three-year TRM after haplo-HSCT were 6% [95% confidence interval (CI), 1-21%], 21% (95% CI, 7-40%), and 47% (95% CI, 20-70%) for the low-, intermediate-, and high-risk group, respectively (P < 0·0001). In the validation cohort, the haplo-HSCT scoring system also separated patients into three risk groups with increasing risk of TRM: intermediate-risk [hazard ratio (HR) 2·45, 95% CI, 0·92-6·53] and high-risk (HR 11·74, 95% CI, 3·07-44·89) compared with the low-risk group (P = 0·001). In conclusion, the haplo-HSCT scoring system could effectively predict TRM after transplantation.

Diagnostic work-up for severe aplastic anemia in children: Consensus of the North American Pediatric Aplastic Anemia Consortium

The North American Pediatric Aplastic Anemia Consortium (NAPAAC) is a group of pediatric hematologist-oncologists, hematopathologists, and bone marrow transplant physicians from 46 institutions in North America with interest and expertise in aplastic anemia, inherited bone marrow failure syndromes, and myelodysplastic syndromes. The NAPAAC Bone Marrow Failure Diagnosis and Care Guidelines Working Group was established with the charge of harmonizing the approach to the diagnostic workup of aplastic anemia in an effort to standardize best practices in the field. This document outlines the rationale for initial evaluations in pediatric patients presenting with signs and symptoms concerning for severe aplastic anemia.

Allogeneic Hematopoietic Stem Cell Transplant Infusion During Venovenous Extracorporeal Membrane Oxygenation Support

Management of hematopoietic stem cell transplant complicated by respiratory failure has been facilitated by the use of extracorporeal membrane oxygenation as a bridge to curative chemotherapeutic options. This is the first report of hematopoietic stem cell transplantation on extracorporeal membrane oxygenation in the adult population.

Incorporating genetic counseling into the evaluation of pediatric bone marrow failure

The timely identification of germline genetic causes of pediatric bone marrow failure (BMF) impacts medical screening practices, family counseling, therapeutic decision-making, and risk of progression to myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). At diagnosis, treatment decisions need to be made quickly to mitigate risks associated with profound cytopenias. As genetic testing options are rapidly evolving, an efficient multi-disciplinary approach and algorithm, including early involvement of a genetics team, is needed to expedite diagnosis and therapeutic decision-making. This process aids in the identification of appropriate candidates for molecular genetic testing. We present our single center experience reviewing the implementation of genetic counseling and a diagnostic and therapeutic algorithm used to guide genetic evaluation of pediatric BMF. Disease-specific next-generation sequencing (NGS) panels were most often pursued in patients who presented with a clinical phenotype consistent with a known inherited BMF syndrome and when trying to reduce incidental or uninformative results. Broader BMF NGS panels were most often utilized when unable to narrow the suspected etiology to a single disorder. Whole exome sequencing helped with optimizing treatment decision-making in higher risk children with BMF who required expedited hematopoietic stem cell transplantation. The experience has led to improvements to our process for evaluating patients with BMF.

The clinical and functional effects of TERT variants in myelodysplastic syndrome

Germline pathogenic TERT variants are associated with short telomeres and an increased risk of developing myelodysplastic syndrome (MDS) among patients with a telomere biology disorder. We identified TERT rare variants in 41 of 1514 MDS patients (2.7%) without a clinical diagnosis of a telomere biology disorder who underwent allogeneic transplantation. Patients with a TERT rare variant had shorter telomere length (P < .001) and younger age at MDS diagnosis (52 vs 59 years, P = .03) than patients without a TERT rare variant. In multivariable models, TERT rare variants were associated with inferior overall survival (P = .034) driven by an increased incidence of nonrelapse mortality (NRM; P = .015). Death from a noninfectious pulmonary cause was more frequent among patients with a TERT rare variant. Most variants were missense substitutions and classified as variants of unknown significance. Therefore, we cloned all rare missense variants and quantified their impact on telomere elongation in a cell-based assay. We found that 90% of TERT rare variants had severe or intermediate impairment in their capacity to elongate telomeres. Using a homology model of human TERT bound to the shelterin protein TPP1, we inferred that TERT rare variants disrupt domain-specific functions, including catalysis, protein-RNA interactions, and recruitment to telomeres. Our results indicate that the contribution of TERT rare variants to MDS pathogenesis and NRM risk is underrecognized. Routine screening for TERT rare variants in MDS patients regardless of age or clinical suspicion may identify clinically inapparent telomere biology disorders and improve transplant outcomes through risk-adapted approaches.

Evolution of haematopoietic cell transplantation for canine blood disorders and a platform for solid organ transplantation

Pre-clinical haematopoietic cell transplantation (HCT) studies in canines have proven to be invaluable for establishing HCT as a highly successful clinical option for the treatment of malignant and non-malignant haematological diseases in humans. Additionally, studies in canines have shown that immune tolerance, established following HCT, enabled transplantation of solid organs without the need of lifelong immunosuppression. This progress has been possible due to multiple biological similarities between dog and mankind. In this review, the hurdles that were overcome and the methods that were developed in the dog HCT model which made HCT clinically possible are examined. The results of these studies justify the question whether HCT can be used in the veterinary clinical practice for more wide-spread successful treatment of canine haematologic and non-haematologic disorders and whether it is prudent to do so.

Transfusions in Aplastic Anemia Patients Cause HLA Alloimmunization: Comparisons of Current and Past Cohorts Demonstrate Progress

Transfusions are the mainstay of supportive therapy in patients with aplastic anemia (AA) and may lead to anti- HLA alloimmunization, thereby also increasing the risk for donor-specific antibodies in the setting of HLA-mismatched transplantation. Historically, AA patients were thought to be at particularly high risk for HLA alloimmunization. In past decades, blood product manufacturing (leukoreduction) and HLA antibody testing have improved significantly by single antigen bead (SAB) technology. It is currently unknown how those developments have impacted HLA alloimmunization and treatment outcome in patients with AA. We retrospectively investigated 54 AA patients treated by immunosuppressive therapy or allogeneic hematopoietic cell transplantation after the introduction of the SAB assay at our center. We compared the HLA antibody results to a historical AA cohort (n = 26), treated before introduction of leukoreduced blood products from 1975 to 1995. HLA alloimmunization was detected in 43 of 54 (80%) recently treated patients. Past pregnancy, female gender, disease severity, age, and a history of other transfusions were significantly associated with a larger number or higher intensity (mean fluorescence intensity) of HLA antibodies. Treatment outcome including bleeding episodes, response to treatment, engraftment, graft-versus-host disease, and overall survival was not associated with HLA alloimmunization. In the historical cohort a significantly higher number of HLA antibodies (P < .01) with a higher mean fluorescent intensity (P < .01) was observed. HLA alloimmunization remains frequent in AA tested by current techniques, but it has significantly decreased since prior decades and does not affect treatment outcome. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Hematopoietic Stem-Cell Transplantation versus Immunosuppressive Therapy in Patients with Adult Acquired Severe Aplastic Anemia: A Cost-Effectiveness Analysis

Objective

Controversy remains regarding which therapy to initially select for severe aplastic anemia (SAA) patients aged 35–50. This cost-effectiveness analysis aimed to use the Markov model to compare immunosuppressive therapy (IST) with hematopoietic stem-cell transplantation (HSCT) in age-stratified patients with SAA.

Methods

A cost-effectiveness analysis using a Markov model compared IST with HSCT in age-stratified patients with SAA. Baseline data were derived from a systematic literature review and collected from Huashan Hospital, Fudan University. The primary outcome was an incremental cost-effectiveness ratio (ICER).

Results

The HSCT strategy dominated in patients aged 18–35 even though it was $146,970 more expensive than IST, and the ICER of HSCT to IST was $14,054.19/quality-adjusted life-year (QALY), which was less than the willingness-to-pay value of $25,397.57/QALY. The IST strategy dominated in patients aged 35–50, because it was $72,009 less expensive than HSCT and yielded 3.24 QALYs more than HSCT. The model was vigorous in the sensitivity analyses of the key variables tested through the plausible ranges that were acquired from costing sources and previously published literature.

Conclusion

The preferred induction strategy for patients aged 18–35 with SAA appears to be HSCT, and the preferred strategy for patients aged 35–50 is IST, which minimizes costs while maximizing QALYs.

Allogeneic Hematopoietic Stem Cell Transplant Offer Good Outcomes in Pediatric Aplastic Anemia: Experience From Developing World

Between 2014 and 2020, 31 patients with severe aplastic anemia (SAA) underwent full match allogeneic hematopoietic stem cell transplantation at our center. Of the 31 patients with SAA, 19 had acquired aplastic anemia, 2 had Diamond Blackfan anemia and 10 had Fanconi anemia. Donors were either matched sibling (n=29), related donors (n=2), or unrelated donors (n=3). Peripheral blood stem cells were the graft source in all the cases except 1. Fludarabine-based reduced intensity conditioning was used in all except for patients with a diagnosis of Diamond Blackfan anemia. All patients except 1 achieved hematologic recovery in the form of neutrophil engraftment at 13 days (range, 9 to 17), whereas platelet engraftment occurred at 14 days (range, 10 to 18). Graft versus host disease (GvHD) prophylaxis consisted of cyclosporine and methotrexate ±antithymocyte globulin (horse/rabbit). Acute GvHD developed in 12.9% patients, whereas no patients developed chronic GvHD till the time of last follow-up. The 2-year overall survival for the entire cohort was 93.21±4.6%. In patients with SAA, allogeneic stem cell transplant using fludarabine-based conditioning regimens are very well tolerated and have excellent outcomes in a full match setting.

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.

Comparisons Between Frontline Therapy and a Combination of Eltrombopag Plus Immunosuppression Therapy and Human Leukocyte Antigen-Haploidentical Hematopoietic Stem Cell Transplantation in Patients With Severe Aplastic Anemia: A Systematic Review

Background and Aims: This study aimed at comparing the efficacy and safety of eltrombopag (EPAG) plus immunosuppressive therapies (ISTs) and haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in the frontline treatment for severe aplastic anemia (SAA) patients. Methods: Four electronic databases and Clinicaltrials.gov were comprehensively searched from January 2010 to August 2020. Studies that aimed at evaluating the efficacy and safety of EPAG+IST or haplo-HSCT in SAA patients were included. One-/2-year overall survival (OS), complete response (CR), and overall response rates (ORRs) were indirectly compared between EPAG+IST and haplo-HSCT. Results: A total of 447 patients involved in 10 cohort studies were found to be eligible for this study. A narrative synthesis was performed due to lack of data directly comparing the outcome of EPAG+IST and haplo-HSCT. Consistent with the analysis results in the whole population, subgroup analyses in the age-matched population showed that there was no significant difference in ORR between EPAG+IST and haplo-HSCT groups. However, the CR rate was lower in the EPAG+IST group when compared with the haplo-HSCT group. The incidence rate of clonal evolution/SAA relapse ranged at 8-14 and 19-31% in the EPAG+IST group but not reported in the haplo-HSCT group. The incidence rate for acute graft vs. host disease (aGVHD) and chronic graft vs. host disease (cGVHD) ranged at 52-57 and 12-67%, respectively, for the haplo-HSCT group. The main causes of deaths were infections in the EPAG+IST group, and GVHD and infections in the haplo-HSCT group. Conclusion: EPAG+IST has a comparable ORR and 1-/2-year OS but lower CR rate when indirectly compared with haplo-HSCT in the frontline treatment of patients with SAA. Patients treated with haplo-HSCT may exhibit a high incidence of GVHD, whereas patients treated with EPAG+IST may experience more relapses or clone evolution.