Guidelines for the diagnosis and management of aplastic anaemia

Indigenous antithymocyte globulin-equine to treat aplastic anaemia in adults: a case series from two centres in northeast India

BACKGROUND

Immunosuppressive therapy is the standard management of adults with aplastic anaemia. Antithymocyte globulin is used as first-line treatment of patients not eligible for bone marrow transplantation. This being a rare disease, available evidence in India is scarce. This study aimed to present experience in treating adult aplastic anaemia patients by immunosuppressive therapy using antithymocyte globulin-equine (Thymogam) in two tertiary care centres of northeast India.

METHODS

This case series was conducted at the Health city hospital, Guwahati, and Excel Care Hospital, Guwahati from 2018 to 2020. Eighteen adult aplastic anaemia patients who were treated by immunosuppressive therapy with antithymocyte globulin-equine (Thymogam) and followed up for two years were included. Treatment response and relapse are described.

RESULTS

All the 18 patients, (14 severe, four very severe) were uniformly treated with immunosuppressive therapy (Thymogam 40 mg/kg/d for four days with oral Cyclosporine from Day-1). Cyclosporin A was used as a concomitant drug in 94.44 % of the patients. At two years of follow up, 66.7 % showed a response and the mortality rate was 11.1 %.

CONCLUSION

The results of this case series substantiate the effectiveness of immunosuppressive therapy with a low-cost preparation of horse antithymocyte globulin (Thymogam) along with cyclosporin A in the management of aplastic anaemia patients not suitable for bone marrow transplantation.

The effect of hetrombopag combined with conventional treatment on immune function and quality of life in patients with severe aplastic anemia

This study aimed to investigate the effect of hetrombopag combined with conventional treatment on immune function in patients with severe aplastic anemia (SAA). Patients were categorized into the control group (n = 50, receiving conventional treatment only) and experimental group (n = 50, receiving hetrombopag combined with conventional treatment). Before treatment and at weeks 18, 24, and 52 after treatment, the two groups were compared in routine blood test indicators, natural killer (NK) cell activity, and peripheral blood inflammatory factor levels. The overall remission rate and incidence of adverse events were also compared between the two groups. Outpatient or telephone follow-up was performed before treatment and at weeks 18, 24, and 52 after treatment to observe patients' immune function, treatment outcome, quality of life, and adverse events. Hemoglobin (Hb), and platelet count (PLT) (P < 0.05), and a rise in NK cell activity (P < 0.05). Interleukin (IL-10) levels were significantly higher, while IL-6 levels were significantly lower in the experimental group compared to the control group (P < 0.05). After receiving the treatment, all scores of SF-36 domains in both groups were higher than before treatment, particularly with higher scores in the experimental group (P < 0.05). Hetrombopag combined with conventional treatment improved the immune function and hematopoiesis of patients with SAA.

[Acquired severe aplastic anemia in emerging countries: Management from allogeneic hematopoietic cell transplantation indication until post-transplant follow-up SFGM-TC]

Management of acquired aplastic anemia (AA) in emerging countries depends on the means of prognostic stratification, treatment and logistics available. During the 13th annual harmonization workshop of the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC), a designated working group reviewed the literature in order to elaborate unified guidelines for allogeneic hematopoietic cell transplantation (Allo-HCT) in this disease. In terms of practice, the conclusions are as follows; The use of anti-tymocyte globuline (ATG) is mainly from rabbit and very little from horse. Access to bone marrow graft, total body irradiation, and the international unrelated donor registries is limited, which justifies the use of peripheral blood stem cells, chemotherapy-based conditioning, and related alternative donor. The workshop recommends matched sibling allo-HCT in all patients aged less than 40 years with acquired severe or very severe AA. For patients aged over than 40 years, or who lack an HLA-identical donor, treatment with the combination of cyclosporin, horse ATG, eltrombopag or cyclosporine, eltrombopag is recommended. If horse ATG and eltrombopag are not available, matched sibling allo-HCT may be indicated as first-line therapy in patients aged between 40-60 years, and good performance status. Although, in patients who have failed immunosuppressive treatments and thrombopoietin agonists, and in the absence of HLA-matched donor, a haplo-identical allo-HCT with modified Baltimore conditioning is recommended.

Diagnosis and management of acquired aplastic anemia in childhood. Guidelines from the Marrow Failure Study Group of the Pediatric Haemato-Oncology Italian Association (AIEOP)

Acquired aplastic anemia (AA) is a rare heterogeneous disorder characterized by pancytopenia and hypoplastic bone marrow. The incidence is 2-3 per million population per year in the Western world, but 3 times higher in East Asia. Survival in severe aplastic anemia (SAA) has improved significantly due to advances in hematopoietic stem cell transplantation (HSCT), immunosuppressive therapy, biologic agents, and supportive care. In SAA, HSCT from a matched sibling donor (MSD) is the first-line treatment. If a MSD is not available, options include immunosuppressive therapy (IST), matched unrelated donor, or haploidentical HSCT. The purpose of this guideline is to provide health care professionals with clear guidance on the diagnosis and management of pediatric patients with AA. A preliminary evidence-based document prepared by a group of pediatric hematologists of the Bone Marrow Failure Study Group of the Italian Association of Pediatric Hemato-Oncology (AIEOP) was discussed, modified and approved during a series of consensus conferences that started online during COVID 19 and continued in the following years, according to procedures previously validated by the AIEOP Board of Directors.

Potential role of B- and NK-cells in the pathogenesis of pediatric aplastic anemia through deep phenotyping

Introduction

Pediatric patients with unexplained bone marrow failure (BMF) are often categorized as aplastic anemia (AA). Based on the accepted hypothesis of an auto-immune mechanism underlying AA, immune suppressive therapy (IST) might be effective. However, due to the lack of diagnostic tools to identify immune AA and prognostic markers to predict IST response together with the unequaled curative potential of hematopoietic stem cell transplantation (HSCT), most pediatric severe AA patients are momentarily treated by HSCT if available. Although several studies indicate oligoclonal T-cells with cytotoxic activities towards the hematopoietic stem cells, increasing evidence points towards defective inhibitory mechanisms failing to inhibit auto-reactive T-cells.

Methods

We aimed to investigate the role of NK- and B-cells in seven pediatric AA patients through a comprehensive analysis of paired bone marrow and peripheral blood samples with spectral flow cytometry in comparison to healthy age-matched bone marrow donors.

Results

We observed a reduced absolute number of NK-cells in peripheral blood of AA patients with a skewed distribution towards CD56bright NK-cells in a subgroup of patients. The enriched CD56bright NK-cells had a lower expression of CD45RA and TIGIT and a higher expression of CD16, compared to healthy donors. Functional analysis revealed no differences in degranulation. However, IFN-γ production and perforin expression of NK-cells were reduced in the CD56bright-enriched patient group. The diminished NK-cell function in this subgroup might underly the auto-immunity. Importantly, NK-function of AA patients with reduced CD56bright NK-cells was comparable to healthy donors. Also, B-cell counts were lower in AA patients. Subset analysis revealed a trend towards reduction of transitional B-cells in both absolute and relative numbers compared to healthy controls. As these cells were previously hypothesized as regulatory cells in AA, decreased numbers might be involved in defective inhibition of auto-reactive T-cells. Interestingly, even in patients with normal distribution of precursor B-cells, the transitional compartment was reduced, indicating partial differentiation failure from immature to transitional B-cells or a selective loss.

Discussion

Our findings provide a base for future studies to unravel the role of transitional B-cells and CD56bright NK-cells in larger cohorts of pediatric AA patients as diagnostic markers for immune AA and targets for therapeutic interventions.

Bone marrow CD8+ Trm cells induced by IL-15 and CD16+ monocytes contribute to HSPC destruction in human severe aplastic anemia

Idiopathic severe aplastic anemia (SAA) is a disease of bone marrow failure caused by T-cell-induced destruction of hematopoietic stem and progenitor cells (HSPCs), however the mechanism remains unclear. We performed single-cell RNA sequencing of PBMCs and BMMCs from SAA patients and healthy donors and identified a CD8+ T cell subset with a tissue residency phenotype (Trm) in bone marrow that exhibit high IFN-γ and FasL expression and have a higher ability to induce apoptosis in HSPCs in vitro through FasL expression. CD8+ Trm cells were induced by IL-15 presented by IL-15Rα on monocytes, especially CD16+ monocytes, which were increased in SAA patients. CD16+ monocytes contributed to IL-15-induced CD38+CXCR6+ pre-Trm differentiation into CD8+ Trm cells, which can be inhibited by the CD38 inhibitor 78c. Our results demonstrate that IL-15-induced CD8+ Trm cells are pathogenic cells that mediate HSPC destruction in SAA patients and are therapeutic targets for future treatments.

Successful haploidentical hematopoietic stem cell transplantation for paroxysmal nocturnal hemoglobinuria with severe pancytopenia developed after long-term aplastic anemia treatment

Haploidentical hematopoietic stem cell transplantation (HSCT) with posttransplant cyclophosphamide is an alternative treatment for aplastic anemia-paroxysmal nocturnal hemoglobinuria (PNH) syndrome with poor prognostic factors. Ravulizumab treatment for PNH before HSCT might have a beneficial effect.

Aplastic Anaemia in Pregnancy: A Case-Based Comprehensive Review of the Literature

Aplastic anaemia (AA) is a rare and life-threatening haematologic disorder characterised by pancytopenia and bone marrow failure. Its occurrence during pregnancy is exceedingly rare, posing significant risks and management challenges for both the mother and the foetus. We present here the case of a 23-year-old female, six months pregnant, diagnosed with severe aplastic anaemia (AA), aiming to highlight the diagnostic challenges and management considerations of AA in pregnancy. Our case underscores the critical nature of considering aplastic anaemia in differential diagnosis for pregnant patients presenting with unexplained pancytopenia. Based on that, we performed a comprehensive literature review of the past 20 years of papers published in the English language identified through searches in PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), Embase and the Cochrane Library, to provide an in-depth analysis of the current understanding of AA in pregnancy. We emphasise the necessity for cautious yet thorough investigation in such cases to avoid complications in both maternal and foetal health, focusing attention on the need for further research into safe and effective treatment protocols for managing AA in pregnancy, given the complexities introduced by the condition and its treatment on pregnancy outcomes.

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.

A multicentre ambispective observational study into the incidence and clinical management of aplastic anaemia in Spain (IMAS study)

Aplastic anemia (AA) is a rare, life-threatening hematological disease, with a poorly defined incidence. As the data available on AA varies substantially worldwide, a multicenter, ambispective, observational study was carried out between 2010 and 2019 to assess the incidence, clinical management and survival of AA at seven Spanish hospitals. The incidence of AA was 2.83 per million inhabitants per year, consistent with that reported previously in Europe, with a median age at diagnosis of 61 years-old (range 12-86), and a similar number of males and females. The initial diagnosis was severe or very severe AA in 55.8% of cases and 93.7% required transfusion. The most frequent first line therapy was anti-thymocyte globulin (ATG) plus cyclosporin A (CsA, 44.2%), followed by other CsA-based regimes (46.3%), with hematopoietic stem cell transplantation an infrequent 1st line therapy. The 6-month response rate was 68.2%, which then increased over a median follow-up of 3.9 years. The 5-year overall survival (5OS) was 73.6%, similar in severe (78.6%) and very severe AA patients (74.6%) but lower in moderate AA (MAA) patients (68.4%). The 5OS was 100% in 0-25 year-old patients but dropping to 58.3% in patients ≥ 60 years-old. At the last contact, 75.8% of the patients were alive. In conclusion, the incidence, characteristics and management of AA in our study are consistent with that reported previously. In terms of survival, although the global long-term OS rate was good, there is room for improvement, particularly in older patients. Finally, what appears to be a worse long-term survival of MAA patients, as reported previously, reinforces the importance of not underestimating this condition when diagnosed as MAA.

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.

Letermovir Effectively Prevents Cytomegalovirus Infection in Patients with Aplastic Anemia After Hematopoietic Stem Cell Transplantation: A Real-World Retrospective Cohort Study

INTRODUCTION

In this single-center retrospective cohort study, we investigated the efficacy of letermovir in preventing Cytomegalovirus (CMV) infection in patients with aplastic anemia (AA) who have undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

Based on whether or not letermovir was used for preventing CMV infection, the patients were categorized into two groups: letermovir and control groups. The overall survival (OS) rate and cumulative incidence of CMV infection during the first 100 days after allo-HSCT were evaluated. The study included 21 matched pairs of patients, identified through propensity score matching analysis, to compare CMV infection rates, treatment efficacy, and regression.

RESULTS

The incidence of CMV infection within 100 days after transplantation was significantly lower in the letermovir group than in the control group (26.5 vs. 77.4%, respectively; P < 0.001), among a total of 87 patients who underwent the transplant. In the matched cohort of 21 patients with AA, the letermovir group also showed a significantly reduced cumulative incidence of CMV infection (14.3 vs. 90.5% in the control group; P < 0.001). Compared to the control group, patients with CMV infection in the letermovir group had lower CMV-DNA load and a shorter clearance time. However, there was no significant difference in OS between both groups (P = 0.34).

CONCLUSIONS

Letermovir effectively prevents CMV infection in allo-HSCT recipients with AA and demonstrates a high safety profile.

Pediatric Bone Marrow Failure: A Broad Landscape in Need of Personalized Management

Irreversible severe bone marrow failure (BMF) is a life-threatening condition in pediatric patients. Most important causes are inherited bone marrow failure syndromes (IBMFSs) and (pre)malignant diseases, such as myelodysplastic syndrome (MDS) and (idiopathic) aplastic anemia (AA). Timely treatment is essential to prevent infections and bleeding complications and increase overall survival (OS). Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for most types of BMF but cannot restore non-hematological defects. When using a matched sibling donor (MSD) or a matched unrelated donor (MUD), the OS after HSCT ranges between 60 and 90%. Due to the introduction of post-transplantation cyclophosphamide (PT-Cy) to prevent graft versus host disease (GVHD), alternative donor HSCT can reach similar survival rates. Although HSCT can restore ineffective hematopoiesis, it is not always used as a first-line therapy due to the severe risks associated with HSCT. Therefore, depending on the underlying cause, other treatment options might be preferred. Finally, for IBMFSs with an identified genetic etiology, gene therapy might provide a novel treatment strategy as it could bypass certain limitations of HSCT. However, gene therapy for most IBMFSs is still in its infancy. This review summarizes current clinical practices for pediatric BMF, including HSCT as well as other disease-specific treatment options.

Alternative treatment modality for severe aplastic anemia in a resource-limited setting: a single-institution prospective cohort study from Upper Egypt

This study compared the efficacy and safety of CsA monotherapy with eltrombopag (E-PAG) + CsA combined treatment in children with severe aplastic anemia (SAA). The study including 30 children had SAA. Ten were a retrospective cohort treated with CsA monotherapy. The other 20 were prospective cohort received E-PAG + CsA. All patients were evaluated for partial (PR) and complete (CR) hematological response at 3, 6, and 12 months. overall response (OR), overall survival rates (OS), and treatment safety. OR for the E-PAG patients was 40% after 3 months of therapy. At 6 months, this had increased to 75% with significantly higher CR rate (40%) than in the CsA group (p = 0.0001). After a year of treatment, the CR for the E-PAG + CsA regimen had increased to 50% and the OR to 85%, compared to 20% in the CsA group (p = 0.0001). The OS at 12 months was 100% in the E-PAG+ CsA group compared to 80% in the CsA cohort. At 24 months, the OS in the E-PAG + CsA group was 90%. In conclusion, E-PAG+ CsA was found to be a safe and effective alternative treatment for children with SAA particularly in countries with limited resources.

Interleukin-6 and interleukin-8 levels in children with aplastic anemia and its correlation with disease severity and response to immunosuppressive therapy

Background

Aplastic anemia (AA) is an uncommon condition characterized by pancytopenia and hypocellular bone marrow. Interleukin (IL)-6 and IL-8 have been shown to inhibit myelopoiesis and are major mediators of tissue damage. The primary goal of this study was to determine the IL-6 and IL-8 levels in children with AA, as well as their relationship to illness severity and immunosuppressive medication response.

Materials and Methods

The IL-6 and IL-8 levels were tested in 50 children aged 3-18 years who had AA. As controls, 50 healthy age and sex matched individuals were used. A sandwich enzyme-linked immunosorbent assay kit (solid-phase) was used to measure IL-6 and IL-8 levels quantitatively. The concentrations of IL-6 and IL-8 in pg/mL were used to represent the results. Immunosuppressive medication was given to the patients in accordance with the British Committee for Standards in Haematology Guidelines 2009.

Results

The patients' average age was 11.3 ± 3.7 years. Patients with AA had significantly higher IL-6 and IL-8 levels than controls (278.88 ± 216.03 vs. 4.51 ± 3.26; P < 0.001) and (120.28 ± 94.98 vs. 1.79 ± 0.78; P < 0.001), respectively. The IL-6 and IL-8 levels were also investigated with respect to AA severity, with statistically significant differences (P < 0.01) between different grading strata. Patients with very severe AA (VSAA) had the highest IL-6 levels (499.52 ± 66.19), followed by severe AA (SAA) (201.28 ± 157.77) and non-SAA (NSAA) (22.62 ± 14.63). For IL-8 levels, a similar trend (P < 0.01) was detected, with values of 209.81 ± 38.85, 92.12 ± 78.0, and 9.29 ± 10.68 for VSAA, SAA, and NSAA, respectively. After 6 months of immunosuppressive treatment (IST), mean levels of IL-6 and IL-8 in responders and nonresponders were again assessed. The mean IL-6 level in the responders' group (46.50 ± 45.41) was significantly lower, when compared to the nonresponders' group (145.76 ± 116.32) (P < 0.001). Similarly, the mean IL-8 level in the responder's group (33.57 ± 27.14) was significantly lower, compared to the nonresponder's group (97.49 ± 69.00) (P < 0.001).

Conclusions

Children with AA had higher IL-6 and IL-8 levels than normal age- and sex-matched controls. Increased levels were linked to the severity of the condition, suggesting that IL may have a role in AA. IL levels can be monitored in AA patients during IST, which can assist in predicting response to IST.

Neonatal outcomes and related risk factors of 30 cases with aplastic anemia in pregnancy: A retrospective study

OBJECTIVE

To analyze the neonatal outcomes of pregnancies complicated by aplastic anemia (AA) and to investigate the underlying risk factors.

METHODS

A single-center retrospective study was performed. Thirty singleton gravidas with AA (AA group) and another thirty singleton gravidas (control group) without immune or blood system disorders who gave birth around the same time were selected. Neonatal outcomes were compared between the two groups. Meanwhile, multivariable analyses were utilized to investigate the association between underlying risk factors and adverse neonatal events.

RESULTS

No neonatal deaths occurred. Compared to the control group, the offspring of women with AA had a smaller gestational age (36 ± 1.9 vs. 39.1 ± 0.9 weeks; P < 0.001) and birth weight (2683.7 ± 479.9 vs. 3324.3 ± 394.1 g; P < 0.001). Newborns of women with AA had a higher risk of premature delivery (53.3 % vs. 3.3 %; P < 0.001), low birth weight (23.3 % vs. 0 %; P < 0.001) and NICU admission (53.3 % vs. 16.7 %; P = 0.003). Multivariate analysis showed neutropenia, anemia and thrombocytopenia as risk factors for premature delivery and admission to NICU. Anemia was independently associated with low birth weight (OR 0.94, 95 % CI 0.9-0.98, P = 0.01).

CONCLUSIONS

Neonatal complications such as premature delivery, low birth weight and NICU admission are more common in pregnant women with AA. Newborn babies' s hematopoietic system did not appear to have been affected. Maintaining a certain level of neutrophils, hemoglobin, and platelets in the mother can improve newborn outcomes.

Aplastic anemia from past to the present: A bibliometric analysis with research trends and global productivity during 1980 to 2022

There is no bibliometric study in the literature on Aplastic Anemia (AA). In the present study, the purpose was to summarize the intellectual structure of the subject, uncover the global productivity in this respect, and identify the latest research trends by performing a bibliometric analysis of the articles published on AA. For this purpose, outputs for different research components of scientific outputs (i.e., countries, institutions, journals, and authors) were analyzed. A total of 3221 articles on Aplastic Anemia published between 1980 and 2022 were analyzed by using various statistical methods and bibliometric approaches. The Spearman Correlation Coefficient was used for correlation analysis and bibliometric network visualization maps were used to identify trending topics, citation analysis, and international collaborations. The top 3 contributing countries to the literature were the USA in this respect (800, 24.8%), China (514, 15.9%), and Japan (442, 13.7%). The top 3 most active institutions were the National Institutes of Health USA (n = 177), National Heart Lung Blood Institute (n = 153), and Udice French Research Universities (n = 136). The top 3 most productive journals were the British Journal of Haematology (n = 239), Blood (n = 181), and Bone Marrow Transplantation (n = 137). The most prolific author was Neal Stuart Young (n = 130). Specific keywords that were most frequently used in articles were severe aplastic anemia, immunosuppressive therapy, pediatrics/children, anti-thymocyte globulin, cyclosporine, hematopoietic stem cell transplantation, myelodysplastic syndromes, Paroxysmal Nocturnal Hemoglobinuria, hepatitis-associated aplastic anemia, allogeneic stem cell transplantation, haploidentical hematopoietic stem cell transplantation, pancytopenia, eltrombopag, fludarabine, Graft-Versus-Host Disease, survival, apoptosis, cytokines, and cyclophosphamide. It was determined that the trend topics in recent years were eltrombopag, COVID-19, Treg, Th17, thrombopoietin receptor agonists, haploidentical hematopoietic stem cell transplantation, haploidentical donor/transplantation, and posttransplantation cyclophosphamide. In the formation of the AA literature, it was determined that the research leadership belonged to the USA, China, Japan, European countries (United Kingdom, Italy, Germany, France, Switzerland), India, and South Korea, which have large economies.

Profile and Predictors of Infection Following Anti-thymocyte Globulin or Anti-lymphocyte Globulin with Cyclosporine in Aplastic Anemia

Immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG) and Cyclosporine (CSA) in aplastic anaemia (AA) results in improvement of blood counts between 3 and 6 months for the majority of patients. Infection is the most lethal complication in aplastic anemia and may arise due to several factors. We performed this study to determine the prevalence and predictors of specific infection types before and after IST. Six hundred and seventy-seven (546 adults; 434 males) transplant ineligible patients received ATG and CSA between 1995 and 2017. All patients who were transplant ineligible and received IST in this period were included. Infections before IST was seen in 209 (30.9%) and in 430 (63.5%) patients post IST. There were 700 infective episodes in the six months post-IST, including 216 bacterial, 78 fungal, 33 viral, and 373 culture-negative febrile episodes. Infections were highest (98, 77.8%) in very severe aplastic anaemia as compared to Severe AA (SAA) and Non-Severe AA (NSAA) (p < 0.001). Infections were also significantly higher in those who did not respond to ATG (71.1% vs. 56.8%, p = 0.003). At six months post-IST were 545 (80.5%) alive, and there were 54 (7.9%) deaths due to infection. Significant predictors of mortality were paediatric AA, very severe aplastic anaemia, pre or post ATG infections, and lack of response to ATG. Mortality was highest in those with combined bacterial and fungal infections post IST (p < 0.001). We conclude that infections are a common complication (63.5%) of IST. Mortality was highest when both bacterial and fungal infections were present. Routine use of growth factors and prophylactic antifungal and antibacterial agents was not part of our protocol, despite which 80.5% of the cohort was alive at the end of six months.

Bone marrow expression of CD68/CD163 macrophages, IL-17 and FOXP3 cells in aplastic anemia and their relation to prognosis

OBJECTIVES

The primary mechanism for bone marrow failure in aplastic anemia (AA) is autoimmune hematopoietic stem cell destruction. AA can be cured with antithymocyte globulin (ATG) treatment, and some smaller studies have indicated that the number of regulatory T cells (Tregs) may be predictive of response. Additionally, AA patients appear to have elevated numbers of Th17 cells and bone marrow macrophages, but outcome data are missing.

METHODS

We performed immunohistochemistry on bone marrow biopsies from 121 ATG-treated AA patients and 14 healthy controls, using antibodies against FOXP3 (for Tregs), IL-17 (for Th17), CD68 (for pan-macrophages) and CD163 (for M2 type macrophages) to study their possible relation to ATG response and AA prognosis.

RESULTS

AA patients had significantly fewer Tregs and Th17 cells but significantly more macrophages compared with controls. Treg, Th17 and pan-macrophage cell numbers were not associated with ATG response or differences in survival. Patients with higher levels of M2 macrophages had improved 5-year overall survival: 79.6% versus 57.4% (p = .017), and this benefit was primarily seen in AA patients with non-severe disease.

CONCLUSIONS

We found that Treg and Th17 cell numbers did not predict ATG response or survival, whereas M2 macrophages may be associated with improved survival.

Impact of Conditioning Regimen and Graft-versus-Host Disease Prophylaxis on The Outcome of Haploidentical Peripheral Blood Stem Cell Transplantation for High-Risk Severe Aplastic Anemia in Children and Young Adults: A Report from the Pediatric Severe Aplastic Anemia Consortium of India

Allogenic hematopoietic cell transplantation (HCT) is the best curative approach for patients with severe aplastic anemia (SAA). The outcomes of HCT from haploidentical family donors (HFDs) have improved, making it a feasible option for patients lacking an HLA-identical donor. However, data on HFD-HCT for younger patients with SAA is sparse. In this multicenter retrospective study, we evaluated the outcomes of 79 patients undergoing HFD-HCT for SAA. All the patients were heavily pretransfused, the median time to HCT was >12 months, and 67% had failed previous therapies. Conditioning was based on fludarabine (Flu)-cyclophosphamide (Cy)-antithymocyte globulin (ATG)/total body irradiation (TBI) with or without thiotepa/melphalan (TT/Mel). Post-transplantation Cy (PTCy) and calcineurin inhibitors (CNIs)/sirolimus were used as graft-versus-host disease (GVHD) prophylaxis with or without abatacept. The rate of primary graft failure (PGF) was 16.43% overall, lower in patients conditioned with TT/Mel. The incidences of acute and chronic GVHD were 26.4% and 18.9%, respectively. At a median follow-up of 48 months, the overall survival (OS) and event-free survival (EFS) were 61.6% and 58.1%, respectively. Both OS and EFS were better in the TT/Mel recipients and with abatacept as GVHD prophylaxis. On multivariate analysis, the use of abatacept was found to favorably impact the outcome variables, including GVHD and EFS. Our study suggests that PTCy-based HFD-HCT is a reasonable option for young patients with high-risk SAA, in whom optimization of conditioning and GVHD prophylaxis might further improve outcomes.

Quality Appraisal of Nutritional Guidelines to Prevent, Diagnose, and Treat Malnutrition in All Its Forms during Pregnancy

This work aimed to identify clinical practice guidelines (CPGs) that include recommendations for the prevention, diagnosis, and treatment of women’s malnutrition during pregnancy and to evaluate the quality of these guidelines using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. We conducted a literature review using PubMed and different websites from January 2009 to February 2021. The quality of the CPGs was independently assessed by reviewers using the AGREE II instrument, which defines guidelines scoring >70% in the overall assessment as “high quality”. The analysis included 43 guidelines. Among the main findings, we identified that only half of the CPGs (51.1%) obtained a final “high quality” evaluation. AGREE II results varied widely across domains and categories. The two domains that obtained the highest scores were scope and purpose with 88.3% (range 39 to 100%) and clarity of presentation with 87.2% (range 25 to 100%). Among the “high quality” CPGs, the best scores were achieved by the three guidelines published by the National Institute of Health and Care Excellence (NICE) and the World Health Organization (WHO). Due to the importance of maternal nutrition in pregnancy, it is essential to join forces to improve the quality of the guidelines, especially in CPGs that do not meet the reference standards for quality.

Efficacy of hematopoietic stem cell transplantation in the treatment of children with non-severe aplastic anemia

BACKGROUND

Non-severe aplastic anemia is more likely to develop into severe aplastic anemia, and there is no widely accepted treatment plan at present. Hematopoietic stem cell transplantation might be a new therapeutic strategy.

METHODS

Retrospectively analyzed 32 patients with non-severe aplastic anemia who underwent hematopoietic stem cell transplantation from September 2007 to September 2020, and the 5-year estimated overall survival rate and the incidence of graft-versus-host disease were analyzed to evaluate the efficacy and safety of hematopoietic stem cell transplantation in the treatment of pediatric non-severe aplastic anemia.

RESULTS

Thirty-two patients who underwent transplantation, 29 patients (90.6%) survived, 3 patients (9.4%) died. The incidence of acute graft-versus-host disease was 51.6% (16/31), including 15 cases (48.4%) of grade I-II and 1 case (3.2%) of grade III-IV. The incidence of chronic graft-versus-host disease was 38.7% (12/31). The 5-year overall survival rate was 91.8%.

CONCLUSIONS

Hematopoietic stem cell transplantation is a practicable, safe, and effective treatment option for non-severe aplastic anemia pediatric patients who are suitable for transplant.

Severe aplastic anemia patients with infection who received an allogeneic hematopoietic stem cell transplantation had a better chance: Long-term outcomes of a multicenter study

Background and aims

How to select the treatment is a challenge for the management of acquired patients with infections. This study aimed at comparing the outcomes of SAA with infections who had an allogeneic hematopoietic stem cell transplantation (allo-HSCT)with that of patients who had an infection and received non-HSCT therapy.

Methods

We retrospectively compared the outcomes of patients with acquired SAA and infections who had an allo-HSCT (n = 141) with that of patients who had an infection and received non-HSCT therapy (n = 186) between July 2004 and January 2020.

Results

The treatment-related mortality (TRM) of grade 1-2 infections in the HSCT and non-HSCT groups was 24.99% and 13.68%, respectively (P = 0.206), while the TRM of grade 3-4 infections was lower in the HSCT group than that observed in the non-HSCT group (18.54% vs. 33.33%, P = 0.036). At 6 months post-treatment, 91.30% patients in the HSCT group and 8.78% patients in the non-HSCT group had achieved a normal blood profile (P &lt; 0.0001). The time required to discontinue transfusions of red blood cells and platelets in the non-HSCT group was longer than in the HSCT group (P &lt; 0.0001). Estimated overall survival (OS) at 6 years was similar in the two groups (75.5% ± 3.9% vs. 76.3% ± 3.1%, P = 0.996), while the estimated failure-free survival (FFS) at 6 years was 75.2% ± 3.8% in the HSCT group and 48.9% ± 3.7% in the non-HSCT group (P &lt; 0.0001). Multivariate analysis showed that younger age, lower grade of infection (grade 1-2), and SAA (vs. very SAA) were favorable factors for OS (P &lt; 0.05), and that the choice of HSCT and younger age were favorable factors for FFS (P &lt; 0.0001).

Conclusion

These results suggest that allo-HSCT has a better chance of a successful outcome than non-HSCT in SAA patients with an infection.

Relationship between CYP2C8, UGT1A1, and ABCG2 gene polymorphisms and the exposure, efficacy, and toxicity of eltrombopag in the treatment of refractory aplastic anemia

PURPOSE

Eltrombopag (ELT) is an effective drug for relapsed/refractory aplastic anemia (AA). Our previous study showed that ELT concentration was correlated with the effects of ELT. However, the factors affecting ELT concentration in patients with relapsed/refractory AA were not clarified. Therefore, we aimed to evaluate correlations between drug disposition-related gene polymorphisms and the concentration, efficacy, and toxicity of ELT.

METHODS

Forty-five patients who underwent ELT administration from January 2018 to January 2019 at Peking Union Medical Colleague Hospital (PUMCH) were included. The corresponding clinical information was also collected. ELT plasma concentrations were detected by high-performance liquid chromatography-mass spectrometry (HPLC/MS). CYP2C8, (UGT)1A1, and ABCG21 were genotyped by polymerase chain reaction (PCR). The influence of gene polymorphisms on the plasma concentration, efficacy, and toxicity of ELT was analyzed.

RESULTS

The mean dose required to obtain the optimal effects was significantly lower in the UGT1A1*6 variant carriers than in the UGT1A1*6 WT carriers. There was a significant correlation between the (UGT)1A1*6 polymorphism and higher ELT plasma concentrations (> 11.2 μg/mL). By logistic regression analysis, the efficacy of ELT was related to plasma concentration and a combined genotype of (UGT)1A1*6 and ABCG2. There were no significant associations between genotypes and adverse drug reactions (ADRs) or ELT concentrations and ADRs.

CONCLUSION

UGT1A1*6 is a predictor of the ELT plasma concentration and may help to determine the initial therapeutic dose in relapsed/refractory AA patients. Both drug exposure and patient genotype should be considered for better responses to ELT.

Population Pharmacokinetics of Cyclosporine in Chinese Pediatric Patients With Acquired Aplastic Anemia

Cyclosporine (CsA) is a component of the first-line treatment for acquired aplastic anemia (acquired AA) in pediatric patients. This study aimed to develop a population pharmacokinetic (PK) model of CsA in Chinese pediatric patients with acquired AA to inform individual dosage regimens. A total of 681 CsA whole blood concentrations and laboratory data of 157 pediatric patients with acquired AA were retrospectively collected from two hospitals in Shanghai. A nonlinear mixed-effect model approach was used to build the population PK model. Potential covariate effects of age, body weight, and biochemical measurements (renal and liver functions) on CsA PK disposition were evaluated. Model fit was assessed using the basic goodness of fit and a visual predictive check. The CsA concentration data were accurately described using a two-compartment disposition model with first-order absorption and elimination. Body weight value was implemented as a fixed allometric function on all clearance and volume of distribution parameters. Total bilirubin level was identified as a significant covariate on apparent clearance (CL/F), with a 1.07% reduction per 1 nmol/L rise in total bilirubin level. The final estimates for CL/F and central volume (Vc/F) were 29.1 L/h and 325 L, respectively, for a typical 28 kg child. Other covariates (e.g., gender, age, albumin, hemoglobin, hematocrit, serum creatinine, and concomitant medication) did not significantly affect the PK properties of CsA. This population PK model, along with a maximum a posteriori Bayesian approach, could estimate individual PK parameters in pediatric patients with acquired AA to conduct individual CsA therapy.

Severe infections and renal dysfunction during immunosuppressive therapy with cyclosporine A for aplastic anemia

Although immunosuppressive therapy (IST) with cyclosporine A (CyA) has been widely used in patients with aplastic anemia (AA), little attention has been given to its safety. This study aimed to clarify the adverse events of IST in patients with AA. We retrospectively identified 42 patients with AA treated with IST. Seventeen of the 42 patients (40%) experienced severe infection at a median of 142 days from the start of IST, and 18 (49%) experienced renal dysfunction at a median of 73 days. A large proportion of infected patients had severe AA (90 vs. 14%, p = 0.056). Notably, all patients with severe infection showed poor response to IST at the time of infection onset. Analysis regarding risk factors for renal dysfunction showed that median age at the initiation of IST was significantly higher in patients with renal dysfunction than those without renal dysfunction (65 years vs. 44 years, p = 0.020). Only 2 of 18 patients showed improvement in serum creatinine levels despite reduction or discontinuation of CyA. Our results suggest that poor responders to IST and elderly patients are at higher risk of severe infection and renal dysfunction, respectively.

Childhood aplastic anaemia with paroxysmal nocturnal haemoglobinuria clones: A retrospective single-centre study in South Africa

Background: Paroxysmal nocturnal haemoglobinuria (PNH) clones in children are rare but commonly associated with aplastic anaemia (AA) and myelodysplasia.Objective: This study aimed to determine the prevalence of PNH clones in paediatric patients with idiopathic AA, identify differences in clinical and laboratory features and outcomes, and determine the impact of clone size on clinical presentation.Methods: Patients with confirmed idiopathic AA who were tested for PNH between September 2013 and January 2018 at the Inkosi Albert Luthuli Central Hospital, Durban, KwaZulu-Natal, South Africa, were included. PNH clones were detected in neutrophils and monocytes by flow cytometry using fluorescent aerolysin, CD24, CD66b and CD14.Results: Twenty-nine children with AA were identified and 11 were excluded. Ten patients (10/18, 55.6%) had PNH clones ranging from 0.11% to 24%. Compared to the PNH-negative group, these children were older (median: 10 years vs 4 years, p = 0.02) and had significantly lower total white cell counts (median 1.7 × 109/L vs 3.2 × 109/L; p = 0.04). There was no difference in median absolute neutrophil count or haemoglobin concentration. Four patients in each group received immunosuppressive therapy (IST). At six months, all four patients with PNH clones had responded, compared to one in the PNH-negative group.Conclusion: More than half of children with AA had a PNH clone. The size of the clone did not impact clinical severity; however, IST use may positively impact prognosis. We recommend early initiation of IST in patients with AA to avoid delays associated with human leukocyte antigen typing. 

A multicentre trial of intensive immunosuppressive therapy combined with umbilical cord blood for the treatment of severe aplastic anaemia

Immunosuppressive therapy (IST) is an effective treatment regimen for severe aplastic anaemia (SAA) patients without HLA-identical donors. This study further compared the outcomes between IST and IIST-UCB in SAA on the basis of research shown that IST combined with umbilical cord blood infusion (IIST-UCB) treated effectively. A total of 123 patients from 11 hospitals in China were enrolled. Sixty-nine patients in IIST-UCB group were treated with ATG + CsA + CTX combined with cord blood, while 54 patients in IST group with ATG + CsA. The overall remission rates (ORRs), complete remission (CR) rates and partial response (PR) rates of IIST-UCB group and IST group at 3 months were 69.67% vs 51.85% (P = .045), 21.74% vs 3.7% (P = .004) and 47.83% vs 48.15% (P = .972), respectively. After 6 months of treatment, they were 76.81% vs 57.41% (P = .022), 37.68% vs 11.11% (P = .001) and 39.13% vs 46.30% (P = .425), respectively. After 1 year of treatment, they were 85.51% vs 61.11% (P = .002), 59.42% vs 25.93% (P = .000) and 26.09% vs 35.19% (P = .275), respectively. The ORRs and CR rates of IIST-UCB group were both significantly higher than IST group after 3 months, 6 months and 1 year of treatment. The neutrophil granulocyte, platelet and haemoglobin recovery times of IIST-UCB group were significantly shorter than IST group. Compared with standard IST, IIST-UCB as an effective therapy for SAA patients without HLA-identical donors accelerated the haematopoietic reconstitution, resulting in higher early CR rates.

Cofilin-1 participates in the hyperfunction of myeloid dendritic cells in patients with severe aplastic anaemia

Cofilin‐1 interacts with actin to regulate cell movement. The importance of cofilin‐1 in immunity has been established, and its involvement in a number of autoimmune diseases has been confirmed. However, its role in severe aplastic anaemia (SAA) remains elusive. Thus, the aim of the current study was to investigate the role of cofilin‐1 in patients with SAA. Flow cytometry, Western blotting and real‐time quantitative reverse transcription‐polymerase chain reaction were performed to detect the mRNA and protein expression of cofilin‐1 in myeloid dendritic cells (mDCs) from patients with SAA. The expression of cofilin‐1 was then suppressed via siRNA, and its effects on mDCs and downstream effector T‐cell function were evaluated. Cofilin‐1 expression was higher in mDCs from patients with SAA and correlated with routine blood and immune indexes. Moreover, cofilin‐1 knockdown in mDCs from patients with SAA reduced their phagocytic capacity, migration capacity, and CD86 expression through F‐actin remodelling, downregulating the stimulatory capacity of mDCs on CD4⁺ and CD8⁺ T lymphocytes. Collectively, these findings indicate that cofilin‐1 participates in the hyperfunction of mDCs in patients with SAA and that the downregulation of cofilin‐1 in mDCs from patients with SAA could be a novel treatment approach for SAA.

Plasma lipidome acts as diagnostic marker and predictor for cyclosporin response in patients with aplastic anemia

The lipid metabolomic profile has been well defined in the pathogenesis and differential diagnosis in patients with different myeloid diseases. We assumed that the serum lipid metabolites could also help the diagnosis and prognostic prediction of aplastic anemia (AA). In this study, serum lipid profiles were explored in AA patients before and after cyclosporin (CsA) treatment. Meanwhile, hypocellular myelodysplastic syndrome (h-MDS) patients and the healthy volunteers were compared as controls. 15 AA patients, 11 h-MDS patients and 20 age and sex matched health controls were enrolled. All the AA patients were diagnosed to be non-severe aplastic anemia with transfusion dependency and were treated by CsA 3-5 mg/kg/d for at least 6 months. AA patients had decreased arachidonic acid pathway metabolites and retinol metabolism-related metabolites as compared with h-MDS and the health (P < 0.05), whereas h-MDS patients had increased metabolism of proline and threonine and abnormal sphingolipid metabolism compared with AA patients and the normal controls. After 6 month of CsA treatment, serum arachidonic acid, PGE2, PGJ2, 15(S)-HETE, leukotriene B4 and Protectin D1 decreased significantly. Patients who had response to CsA had higher levels of baseline protectin D1 (P = 0.011), leukotriene B4 (P = 0.011), 15(S)-HETE (P = 0.004) and all-trans-retinal (P = 0.000) than those who had no response.

Effects of cimetidine on ciclosporin population pharmacokinetics and initial dose optimization in aplastic anemia patients

The present study aimed to explore the effects of cimetidine on ciclosporin population pharmacokinetics and initial dose optimization in aplastic anemia patients. Aplastic anemia patients were used to establish a population pharmacokinetic model by the nonlinear mixed effect (NONMEM), and concentrations of ciclosporin were simulated by Monte Carlo method. With the same weight, the ciclosporin clearance rates were 0.387:1 in patients with or without cimetidine, respectively. In the measured ciclosporin concentrations, compared to aplastic anemia patients without cimetidine, ciclosporin concentrations were higher in patients with cimetidine (P < 0.01). Further research found that at the same body weight and same dose, ciclosporin concentrations in aplastic anemia patients with cimetidine were indeed higher than those in patients without cimetidine (P < 0.01). The initial recommended ciclosporin dose for patients without cimetidine were 7mg/kg splited into two doses for weight of 40-60kg, and 6mg/kg splited into two doses for weight of 60-100kg. The patients with cimetidine were recommended to take 3mg/kg ciclosporin splited into two doses for weight of 40-100kg. It was the first time to explore the effects of cimetidine on ciclosporin population pharmacokinetics and initial dose optimization in aplastic anemia patients. Patients coadministration of cimetidine, may need low ciclosporin dose.

Abnormal expression of histone acetylases in CD8+ T cells of patients with severe aplastic anemia

Introduction

We aimed to investigate the balance between the mRNA levels of histone acetyltransferases (HATs) and histone deacetylases (HDACs) in CD8+ T cells of patients with severe aplastic anemia (SAA).

Methods

Twenty untreated SAA patients, 18 remission SAA patients (R‐SAA), and 22 normal controls were evaluated. The mRNA expression levels of HATs, HDACs, and IFNG in CD8+ T cells were measured by real‐time quantitative reverse transcription polymerase chain reaction.

Results

Histone acetylase EP300 and CREBBP mRNA levels were significantly elevated in CD8+ T cells of SAA patients compared with the normal controls (both p < 0.05). No significant differences were observed in HDAC1 and HDAC7 mRNA between SAA patients and the normal controls. There was an obvious positive correlation between IFNG and EP300 (r = 0.5126, p < 0.01), and CREBBP (r = 0.4663, p < 0.05), respectively, in SAA and R‐SAA patients. In addition, EP300 and CREBBP mRNA levels were clearly correlated with clinical parameters of peripheral blood and bone marrow in those patients.

Conclusion

Our findings suggest that EP300 and CREBBP are increased in CD8+ T cells of SAA patients and are correlated with disease severity. The imbalances in HATs and HDACs may play a role in activating CD8+ T cells to promote the immune pathogenesis of SAA.

Lymphocyte Activation Gene 3 Single-Nucleotide Polymorphisms in Bone Marrow Failure Diseases

Introduction. Lymphocyte activation gene 3 (LAG3) is an inhibitory checkpoint protein expressed on activated T effector, T regulatory, and natural killer cells. The main function of LAG3 is the regulation of immune homeostasis. Several studies have suggested its role in malignant and autoimmune diseases. The objective of this study was to explore the association between LAG3 single-nucleotide polymorphisms (SNPs) and bone marrow failure diseases. Methods. Sixty-two patients newly diagnosed with bone marrow failure diseases in the Hematology Department of Tianjin Medical University General Hospital between January 2019 and December 2020 and 16 healthy controls were enrolled in this study. SNPs in LAG3 were investigated by performing Sanger sequencing, and the association of the detected SNPs with bone marrow failure diseases was analyzed. Results. Eleven SNPs were identified. Among them, the frequency of LAG3 rs1941928301 (C>T) was statistically different among the groups ( $P=0.013$ ). It was higher in the myelodysplastic syndrome (MDS) group than that in the severe aplastic anemia (SAA) group ( $P=0.004$ ) and that in the healthy control group ( $P=0.009$ ). Conclusions. LAG3 rs1941928301 (C>T) might be associated with a higher risk of MDS. The detected LAG3 SNPs have no apparent effect on susceptibility to SAA and immune-related pancytopenia (IRP).

Multi-Omics Profiling Identifies Pathways Associated With CD8+ T-Cell Activation in Severe Aplastic Anemia

Severe aplastic anemia (SAA) is an autoimmune disease characterized by immune-mediated destruction of hematopoietic stem and progenitor cells. Autoreactive CD8⁺ T cells have been reported as the effector cells; however, the mechanisms regulating their cell activation in SAA remain largely unknown. Here, we performed proteomics and metabolomics analyses of plasma and bone marrow supernatant, together with transcriptional analysis of CD8⁺ T cells from SAA patients and healthy donors, to find key pathways that are involved in pathogenic CD8⁺ T-cell activation. We identified 21 differential proteins and 50 differential metabolites in SAA patients that were mainly involved in energy metabolism, complement and coagulation cascades, and HIF-1α signaling pathways. Interestingly, we found that these pathways are also enriched in T cells from SAA patients by analyzing available single-cell RNA sequencing data. Moreover, CD8⁺ T cells from SAA patients contain a highly activated CD38⁺ subset, which was increased in the bone marrow of SAA patients and a murine model of SAA. This subset presented enriched genes associated with the glycolysis or gluconeogenesis pathway, HIF-1α signaling pathway, and complement associated pathways, all of which were of importance in T-cell activation. In conclusion, our study reveals new pathways that may regulate CD8⁺ T-cell activation in SAA patients and provides potential therapeutic targets for SAA treatment.

High Failure-Free Survival after Unrelated Donor Peripheral Blood Stem Cell Transplantation in Pediatric Severe Aplastic Anemia

The use of alternative donor peripheral blood stem cell transplantation (PBSCT) has increased in recent years. In this study, we analyzed the effect of stem cell source and HLA disparity on outcomes in pediatric patients with severe aplastic anemia (SAA). A total of 134 patients who underwent HSCT with nonmyeloablative conditioning between 2006 and 2020 were enrolled and classified into 3 groups: HLA-matched bone marrow transplantation (M-BMT; n = 24), HLA-matched PBSCT (M-PBSCT; n = 66), and HLA-mismatched PBSCT (MM-PBSCT; n = 44). Significantly higher stem cell doses were obtained for PBSCT than for BMT. A total of 13 patients experienced secondary graft failure (GF), with a cumulative incidence (CI) of 10.0%. HLA-mismatched PBSCT and a very severe degree of disease significantly decreased the incidence of secondary GF. The CI of grade II-IV acute graft-versus-host disease (GVHD) was significantly higher in PBSCT than in BMT, but the CI of grade III-IV acute GVHD and CI of chronic GVHD requiring systemic treatment did not increase in PBSCT. The estimated 5-year overall survival (OS), failure-free survival (FFS), and GVHD-free failure-free survival (GFFS) of the total cohort were 93.0%, 89.5%, and 77.5%, respectively. The most favorable FFS was observed in the MM-PBSCT group (97.6%; P = .03), whereas OS and GFFS were similar across the 3 groups. In multivariate analysis, HLA mismatch and short time from diagnosis to transplantation were associated with superior FFS. Unrelated donor PBSCT with low-intensity SAA conditioning showed favorable outcomes in terms of low rate of secondary GF, higher FFS, and manageable GVHD regardless of HLA compatibility. Our findings suggest the feasibility of PBSCT from unrelated donors, resulting in the possible expansion of the donor pool in transplantation for pediatric SAA. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Prospective validation of the provisional entity of refractory cytopenia of childhood, proposed by the World Health Organization

In 2008, the World Health Organization proposed a new entity of childhood myelodysplastic syndrome (MDS), which was referred to as refractory cytopenia of childhood (RCC). However, whether this morphological classification reflects clinical outcomes remains unclear. We performed a prospective evaluation of bone marrow morphology in 252 children with acquired bone marrow failure between 2009 and 2013. Of 252 patients, 63 were diagnosed with aplastic anaemia (AA), 131 with RCC without multilineage dysplasia (RCC-w/o-MLD) and 58 with RCC with MLD (RCC-MLD). One patient with AA, three with RCC-w/o-MLD and nine with RCC-MLD presented with chromosomal abnormalities at diagnosis (P = 0·001). The response rates to immunosuppressive therapy (IST) at 6 months and the cumulative incidence of clonal evolution at 5 years did not significantly differ among the three groups. A multivariate analysis revealed that the morphological classification of RCC-MLD was a significant risk factor for secondary graft failure after haematopoietic cell transplantation (HCT) (P = 0·003). In view of these findings, RCC could be divided into two categories, RCC-w/o-MLD and RCC-MLD, because children with this condition exhibited a distinct morphology, frequent chromosomal abnormalities at diagnosis and a high frequency of secondary graft failure after HCT.

Myeloid dendritic cells in severe aplastic anemia patients exhibit stronger phagocytosis

BACKGROUND

A deeper understanding of the pathogenesis of severe aplastic anemia (SAA) is urgently warranted to achieve better therapeutic effects. The objective of this study was to investigate the phagocytosis of myeloid dendritic cell (mDC) in SAA patients.

METHODS

Myeloid dendritic cells were induced in vitro from bone marrow mononuclear cells from 26 SAA patients and 12 normal controls (HCs). The phagocytosis of mDCs was detected by flow cytometry using FITC-Dextran (40KD), and its correlation with the immune status and severity of the disease was analyzed.

RESULTS

The phagocytosis of mDC from untreated SAA patients was significantly stronger than that from complete remission group and HC group (p < 0.05). There was no statistical difference between the latter two groups (p > 0.05). The phagocytosis of mDC from SAA patients correlated positively with the concentration of interleukin (IL)-2 (r = 0.389, p < 0.05), and IL-4 (r = 0.556, p < 0.05), negatively with CD4⁺ /CD8⁺ ratio (r = -0.421, p < 0.05). It also had negative correlations with the level of hemoglobin (r = -0.393, p < 0.05), white blood cell (r = -0.436, p < 0.05), platelet (r = -0.431, p < 0.05), and reticulocyte (r = -0.447, p < 0.05). The phagocytosis of mDC does not correlate with the response to IST.

CONCLUSIONS

The increased phagocytosis of mDC in untreated SAA patients may contribute to abnormal activation of T helper (Th) and subsequent cytotoxic T lymphocyte (CTL) activation in these patients. It may be involved in the immune pathogenesis of SAA.

Upfront Alternative Donor Transplant versus Immunosuppressive Therapy in Patients with Severe Aplastic Anemia Who Lack a Fully HLA-Matched Related Donor: Systematic Review and Meta-Analysis of Retrospective Studies, on Behalf of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation

Idiopathic aplastic anemia is a rare and life-threatening disorder, and hematopoietic stem cell transplantation (HSCT) from a matched sibling donor (MSD) is the standard treatment strategy for young patients. Alternative donor transplantation (ADT) from a matched unrelated donor or an HLA haploidentical donor is not commonly used in the frontline setting. This systematic review/meta-analysis was conducted to compare ADT as an upfront, rather than delayed, treatment strategy in the absence of an MSD to immunosuppressive therapy (IST) in severe aplastic anemia (SAA). We searched PubMed/MEDLINE and Embase (1998 to 2019) for studies that compared the outcomes of ADT with IST as upfront therapy in patients with SAA. We included studies with 5 patients or more in each arm. Studies that included patients with inherited forms of bone marrow failure syndromes were excluded. The primary outcome was the 5-year overall survival (OS) rate. Five studies met the inclusion criteria and were included in this meta-analysis. The pooled 5-year odds ratio (OR) for OS was statistically significant at 0.44 (95% confidence interval [CI], 0.23 to 0.85) in favor of upfront ADT. In addition, survival was compared between upfront ADT versus salvage ADT in 6 studies. The pooled 5-year OR for OS was statistically significant at 0.31 (95% CI, 0.15 to 0.64) in favor of upfront ADT. Although this analysis has some limitations, including the retrospective nature of the included studies, the lack of ethnic diversity, the predominantly pediatric population, and the relatively suboptimal IST regimen used in some of the studies, it indicates that upfront ADT is a potential alternative treatment option in young and pediatric SAA patients who lack an HLA identical sibling donor, particularly when optimal IST is not available. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Inefficacy of Immunosuppressive Therapy for Severe Aplastic Anemia Progressing From Non-SAA: Improved Outcome After Allogeneic Hematopoietic Stem Cell Transplantation

Background and Aims

This study aimed at comparing the efficacy and safety of severe aplastic anemia (SAA) cases that had met the criteria for SAA at the time of diagnosis (group A) with SAA that had progressed from non-SAA (NSAA) (group B), both undergoing first-line immunosuppressive therapy (IST). Additionally, group B was compared with SAA that had progressed from NSAA and who had been treated by allogeneic hematopoietic stem cell transplantation (allo-HSCT) (group C).

Methods

We retrospectively compared 608 consecutive patients in group A (n = 232), group B (n = 229) and group C (n = 147) between June 2002 and December 2019. Six months after treatment, the rate of overall response and the fraction of patients who had achieved normal blood values, treatment-related mortality (TRM), secondary clonal disease, 5-year overall survival (OS) and failure-free survival (FFS) were indirectly compared between group A and group B, group B and group C.

Results

Six months after treatment, the rate of overall response and the fraction of patients who had achieved normal blood values in group A was higher than in group B (65.24% vs. 40.54%, P < 0.0001; 23.33% vs. 2.25%, P < 0.0001); the same was true for group C (92.50% vs. 2.25%, P < 0.0001). The rate of relapse in group B was higher than in group C (P < 0.0001), but there were no differences in TRM and secondary clonal disease (P > 0.05). There were no differences in estimated 5-year OS between groups A and B (83.8% ± 2.6% vs. 85.8% ± 2.6%, P = 0.837), or between B and C (85.8% ± 2.6% vs. 77.9% ± 3.4%, P = 0.051). The estimated 5-year FFS in groups A and C was higher than for group B (57.1% ± 3.3% vs. 39.7% ± 3.4%, P < 0.001; 76.7% ± 3.5% vs. 39.7% ± 3.4%, P < 0.0001).

Conclusion

These results indicate that IST is less effective in SAA progressing from non-SAA but allo-HSCT can improve outcomes.

Plasma Metabolomic and Intestinal Microbial Analyses of Patients With Severe Aplastic Anemia

Aplastic anemia results from bone marrow failure caused by an autoimmune abnormality, but the pathogenesis of severe aplastic anemia (SAA) is not well characterized. To identify potential metabolic markers of SAA and to further elucidate the pathogenetic mechanisms of SAA, we performed a metabolomic study of plasma samples and characterized the intestinal microbiota of patients with SAA and healthy controls. Patients with SAA had more Enterobacteriales and Lactobacillales, but fewer Bacteroidales, Clostridiales, and Erysipelotrichales than healthy controls. At the species level, the abundances of Escherichia coli and others including Clostridium citroniae were higher, whereas those of Prevotella copri, Roseburia faecis, and Ruminococcus bromii were lower. Eight metabolites showed significantly different plasma concentrations in the SAA and healthy control groups. Coumaric acid, L-phenylalanine, and sulfate were present at higher concentrations in the SAA group; whereas L-glutamic γ-semialdehyde, theobromine, 3a, 7a-dihydroxy-5b-cholestane, γ-δ-dioxovaleric acid, and (12Z)-9, 10-dihydroxyoctadec-12-enoic acid were present at lower concentrations. In conclusion, patients with SAA show abnormalities in both their plasma metabolomes and intestinal microbial compositions. These differences might reflect the molecular mechanisms involved in the defective immunity that characterizes SAA.

Immunoexpression of CD34, CD117, and p53 in Hypocellular Bone Marrow Disorders

Objectives  Hypocellular bone marrow (BM) disorders comprise heterogeneous entities associated with peripheral cytopenias and decreased production of hematopoietic cells in BM. This study was undertaken to analyze immunohistochemical expression of CD34, CD117, and p53 in morphologically diagnosed patients of hypocellular BM (aplastic anemia [AA], hypocellular myelodysplastic syndrome [h-MDS], and hypocellular acute myeloid leukemia [h-AML]).

Materials and Methods  BM specimens were obtained from patients presenting with pancytopenia/bicytopenia. On 30 patients diagnosed as hypocellular BM, immunohistochemistry (IHC) for CD34, CD117, and p53 was performed.

Results  BM cellularity was < 30% in all (100%) patients. Blast count was increased in h-MDS and h-AML. Features of dysplasia were noted in six (20%) patients. Out of these, three patients were diagnosed as h-MDS having bilineage/trilineage dysplasia, and the other three patients were of AA (11.5% patients) displaying only dyserythropoiesis. On IHC, percentage of BM CD34+ cells was increased in h-MDS+ h-AML (3.87 ± 0.86) as compared with AA (0.19 ± 0.15) and controls (0.81 ± 0.21), p  = 0.01. Percentage of BM p53+ cells was also increased in h-MDS+ h-AML (2.9 ± 2.07) as compared with AA and controls, which did not show any p53+ cells, p  = 0.0. No statistically significant difference was observed in the expression of CD117 in h-MDS+ h-AML (4.95 ± 3.40) compared with AA (4.49 ± 1.07), p  = 0.99.

Conclusion  The study demonstrates the usefulness of CD34 and p53 immunoexpression as an important ancillary method in distinguishing various hypocellular BM disorders, especially h-MDS and AA. However, the role of CD117 remains unclear and needs to be evaluated further by larger studies.

Haploidentical haematopoietic stem cell transplantation for the treatment of severe aplastic anaemia patients with high-risk factors who lack an HLA-matched sibling donor

This study aimed to analyse the efficacy of haploidentical donor (HID) haematopoietic stem cell transplantation as a first-line treatment for severe aplastic anaemia (SAA) with high-risk factors (infection or very severe aplastic anaemia,VSAA) in patients who lack an HLA-matched sibling donor (MSD). The patients with infection were treated with anti-infection therapy, and allogeneic haematopoietic stem cell transplantation (HSCT) was carried out after the infection being effectively controlled was in accordance with the stable infection (SI) standard. A total of 44 SAA patients receiving MSD transplantation (n=19) and HID transplantation (n=25) were included in this study. There was no significant difference in neutrophil engraftment between the two groups [MSD vs. HID, 19 (11-38) vs. 22 (15-47).P=0.241], and the difference in platelet engraftment was statistically significant [MSD vs. HID, 11(7-33) vs. 20 (12-69), P=0.034]. The HID group exhibited a higher incidence of grade II-IV acute graft-versus-host disease (aGVHD) (HID vs. MSD, 48.0% vs10.5%, P=0.034)and a higher incidence of chronic GVHD (cGVHD) than the MSD group (64.0% vs. 21.1%, P=0.026). There was no significant difference between overall survival (OS) following HID and MSD transplantation (84.0% vs. 89.5%, P=0.664) and failure-free survival (FFS)(80.0% vs. 84.2%, P=0.965). The interval from diagnosis to transplantation (>50d) and ECOG (>2) were independent factors associated with OS and FFS. HID HSCT may be an effective and safe option for SAA patients with high-risk factors who lack an MSD.

Unresponsive Severe Aplastic Anemia in a Young Patient: Case Report and Short Review of the Literature

Aplastic anemia or medullary aplasia is a medical condition characterized by pancytopenia and is associated with a high prevalence of morbidity and mortality. In patients in whom bone marrow transplantation cannot be attempted, an immunosuppressive regimen is considered to be the first-line therapy. Also, the addition of eltrombopag from the first day of immunosuppressive treatment seems to significantly increase response rate. Unfortunately, there are a small number of patients who remain unresponsive to all these therapies. Here we present the case of a young woman who was referred by the family doctor complaining of marked physical asthenia, new onset dyspnea, and dizziness. Apart from a severe pancytopenia, no further changes have been brought to light by paraclinical investigations. After multiple secondary causes were excluded, the patient was diagnosed with idiopathic aplastic anemia. Even if bone marrow transplant was the first-line therapy in this case, because of the severe leukopenia, it was not possible to determine the HLA type. Therefore, the patient was prescribed immunosuppressive treatment. Despite the three drug-associated therapy (horse anti-thymocyte globulin, cyclosporin A, and eltrombopag), the response was unsatisfactory, with the persistence of severe pancytopenia.

Adult aplastic anemia in Thailand: incidence and treatment outcome from a prospective nationwide population-based study

The incidence and outcomes of aplastic anemia (AA) in Asia remain limited. This study aimed to explore the incidence and outcomes of patients with adult AA across the country of Thailand. This is a prospective multi-center nationwide population-based observational study of AA patients aged at least 15 years old, diagnosed from August 2014 to July 2016, with a longitudinal follow-up period over 2 years. There were 348 newly diagnosed adult AA patients during the enrollment period, giving an annual incidence of 4.6 per million. The incidence of severe (SAA) and very severe aplastic anemia (VSAA) (3.8 per million) was higher than non-severe AA (NSAA, 0.8 per million). The peak incidence was observed in the patients aged from 80 to 89 years old (14.4 per million). The 2-year overall survival (OS) in NSAA, SAA, and VSAA were 65.5%, 49.3%, and 20.1%, respectively (P < 0.001). With regard to the response to immunosuppressive therapy, the overall response rate (ORR) in SAA/VSAA treated with rabbit anti-thymocyte globulin with/without cyclosporin A (rATG ± CsA) were significantly superior to those treated with CsA alone, or anabolic steroids (44.4% vs 36.4% and 31.2%, respectively, P < 0.001). The 2-year OS in SAA/VSAA treated with rATG ± CsA, CsA, and anabolic steroids were 54.8%, 54.5%, and 37.6% (P = 0.037), respectively. The incidence of adult AA in Thailand is higher than those in Western countries, and the peak incidence is in the elderly. rATG ± CsA provided a better response than anabolic steroids, translating to the superior survival in SAA/VSAA treated with rATG ± CsA.