Natural history of moderate aplastic anemia in children

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.

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.

Aplastic Anemia as a Roadmap for Bone Marrow Failure: An Overview and a Clinical Workflow

In recent years, it has become increasingly apparent that bone marrow (BM) failures and myeloid malignancy predisposition syndromes are characterized by a wide phenotypic spectrum and that these diseases must be considered in the differential diagnosis of children and adults with unexplained hematopoiesis defects. Clinically, hypocellular BM failure still represents a challenge in pathobiology-guided treatment. There are three fundamental topics that emerged from our review of the existing data. An exogenous stressor, an immune defect, and a constitutional genetic defect fuel a vicious cycle of hematopoietic stem cells, immune niches, and stroma compartments. A wide phenotypic spectrum exists for inherited and acquired BM failures and predispositions to myeloid malignancies. In order to effectively manage patients, it is crucial to establish the right diagnosis. New theragnostic windows can be revealed by exploring BM failure pathomechanisms.

Cyclosporine Monotherapy in Pediatric Patients With Non-severe Aplastic Anemia: A Retrospective Analysis

Objective

The management of children with non-severe aplastic anemia (NSAA) is undefined and the efficacies and benefits of immunosuppressive therapy remain inconsistent. The study aimed to investigate the efficacy of Cyclosporine (CsA) monotherapy for pediatric NSAA.

Methods

Clinical data of children with NSAA who had been treated with CsA monotherapy at the outpatient department of Beijing Children's Hospital, Capital Medical University, National Children's Medical Center from January 2017 to March 2021 was collected retrospectively. Patients who had been treated <1 years until the end of follow-up were excluded. Transfusion-independent NSAA was further divided into moderate NSAA and mild NSAA according to the degree of cytopenia. Progression was defined as the development of transfusion-dependent AA or SAA and relapse was considered when treatment failed after initial response.

Results

A total of 95 pediatric patients with NSAA were enrolled in this study with 49 (51.6%) patients confirmed as mild NSAA, 38 (40%) as moderate NSAA and 8 (8.4%) as transfusion-dependent NSAA. The median treatment time of CsA was 22 (12–44) months. The overall response rate (ORR) was 57.9%, with 30.5% CR and 27.4% PR. Unexpectedly, patients with mild NSAA acquired lowest ORR (46.9%), then patients with moderate NSAA (63.2%), while 8 patients who were transfusion-dependent all had an active response to CsA. The granulocyte and megakaryocyte response was 46.9 and 55.8% respectively, while the erythrocyte response rate was as low as 22.5%. Univariate analyses revealed that patients with lower platelet count and higher interleukin 10 level predict an active response to CsA while higher level of fetal hemoglobin (HbF) tended to be a negative factor. Data of Treg cells before and after 1 year's treatment was available in a total number of 40 patients. Paired comparison found that the percentage of Treg cells in CD4+ T cells was decreased after 1 year's treatment of CsA (6.78 ± 2.72 vs. 5.23 ± 2.06, P = 0.001),both in responders and non-responders. The degree of decline in Treg cells between two distinctive response groups had no significant difference (P>0.05). With a median follow-up time of 22 months, 10.9% of responders relapsed and maintained NSAA while 27.5% of non-responders progressed to SAA or became transfusion-dependent. The overall progression rate was 11.6%.

Conclusion

CsA monotherapy had heterogeneous effects in the treatment of children NSAA Treatment approaches should be hierarchical and individual in clinical. Patients with lower platelet count and higher interleukin 10 level predicted an active response to CsA. While higher level of fetal hemoglobin (HbF) tended to be a negative factor. The percentage of Treg cells in CD4+ T cells was decreased broadly after treatment.

Atypical Outcomes for Hepatitis-associated Acquired Aplastic Anemia: 2 Case Studies and Review of the Literature

There is little data specifically dedicated to the long-term outcomes of the hepatitis-associated variant of aplastic anemia (HAAA). A majority of patients with nonsevere (moderate) aplastic anemia progress to severe aplastic anemia, and severe aplastic anemia typically results in death if left untreated. We present 2 unique cases of HAAA that contribute to our knowledge of the natural history of this disease variant. One patient had moderate HAAA that never progressed to severe disease. The second patient had severe HAAA that spontaneously resolved without treatment. The rare possibility of moderate HAAA failing to progress to fulfill severe criteria, or of severe HAAA spontaneously improving, may complicate early treatment decisions for some patients.

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

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

Etio-Hematological Profile and Clinical Correlates of Outcome of Pancytopenia in Children: Experience From a Tertiary Care Center in North India

Introduction Pancytopenia is a clinical entity encountered in pediatric practice as a feature of various benign and malignant disorders. It describes the simultaneous presence of anemia, leucopenia and thrombocytopenia. Attempts to identify the correct etiology and gauging the severity of pancytopenia will help to determine the management and prognosis of the patients. Objectives To study etio-hematological profile, clinical correlates and outcome of pancytopenia in Indian children Methods This prospective observational study of children with pancytopenia was conducted at a tertiary care center from August 2015 to July 2016. Clinical, hematological and bone marrow studies were performed and patients were followed for one year. The collected data were statistically analyzed. Results Out of 84 cases, the mean age at diagnosis was 70 (70.77±4.8) months. Bone marrows showed aplastic changes in 37% and hyperplasia in 14% of patients. In our study, most common causes were aplastic anemia, acute leukemia and nutritional anemia. During the first year of follow-up, 67% pancytopenics survived and 12% succumbed (rest discontinued treatment) with ~26% of aplastic anemia (7/27 cases) and 9% of acute leukemia (2/22 cases) not surviving. Anthropometric status of patients and severity in aplastic anemia were significantly associated (p < 0.05) with outcome. Conclusion The data gathered support a complex picture for pancytopenia in our study population since both benign nutritional deficiencies and malignant hematological neoplasms were common. Bone marrow studies seem to be of salient use in delineating etiology. As the outcome is multifactorial, factors like anthropometry, hematological parameters have a bearing on prognosis.

Eltrombopag for patients with moderate aplastic anemia or uni-lineage cytopenias

There is no standard or widely effective treatment of patients with moderate aplastic anemia (MAA) or hypo-productive uni-lineage cytopenias (UC). Eltrombopag (EPAG), a small molecule thrombopoietin mimetic, has previously been shown to result in durable multi-lineage hematologic responses with low toxicity in patients with refractory severe aplastic anemia (SAA). Its safety and efficacy in MAA are unknown. This prospective phase 2 study enrolled previously untreated and treated MAA and UC patients with clinically relevant cytopenias. EPAG was administered at doses escalating from 50 to 300 mg/d. Hematologic responses were assessed at 16 to 20 weeks. Responding patients were continued on EPAG until reaching defined robust or stable blood counts. EPAG was reinstituted for relapse. Thirty-four patients were enrolled between 2012 and 2017, including 31 with MAA and 3 with UC. Seventeen patients responded in at least 1 eligible lineage by the primary end point. A striking improvement in anemia was observed in a patient with Diamond-Blackfan anemia. EPAG was well tolerated, and it was discontinued for robust or stable blood counts in 12 of 17 patients after a median of 8 months. A majority required re-initiation of EPAG for declining counts, and all regained response. Two of 34 patients developed non-chromosome 7 bone marrow cytogenetic abnormalities while taking EPAG, without dysplasia or increased blasts. Somatic mutation allele frequencies in cancer genes did not increase overall on EPAG. EPAG is a well-tolerated oral treatment of cytopenias in patients with MAA/UC. This trial was registered at www.clinicaltrials.gov as #NCT01328587.

Aplastic anaemia: Current concepts in diagnosis and management

Aplastic anaemia is a rare, previously fatal condition with a significantly improved survival rate owing to advances in understanding of the pathophysiology and improved treatment strategies including haematopoietic stem cell transplantation. Although a rare condition, aplastic anaemia continues to present a high burden for affected patients, their families and the health system due to the prolonged course of disease often associated with high morbidity and the uncertainty regarding clinical outcome. Modern molecular and genetic techniques including next-generation sequencing have contributed to a better understanding of this heterogeneous group of conditions, albeit at a cost of increased complexity of clinical decision-making regarding prognosis and choice of treatment for individual patients. Here we present a concise and comprehensive review of aplastic anaemia and closely related conditions based on extensive literature review and long-standing clinical experience. The review takes the reader across the complex pathophysiology consisting of three main causative mechanisms of bone marrow destruction resulting in aplastic anaemia: direct injury, immune mediated and bone marrow failure related including inherited and clonal disorders. A comprehensive diagnostic algorithm is presented and an up-to-date therapeutic approach to acquired immune aplastic anaemia, the most represented type of aplastic anaemia, is described. Overall, the aim of the review is to provide paediatricians with an update of this rare, heterogeneous and continuously evolving condition.

Distinctive and common features of moderate aplastic anaemia

The therapy algorithm for severe aplastic anaemia (sAA) is established but moderate AA (mAA), which likely reflects a more diverse pathogenic mechanism, often represents a treatment/management conundrum. A cohort of AA patients (n = 325) was queried for those with non‐severe disease using stringent criteria including bone marrow hypocellularity and chronic persistence of moderately depressed blood counts. As a result, we have identified and analyzed pathological and clinical features in 85 mAA patients. Progression to sAA and direct clonal evolution (paroxysmal nocturnal haemoglobinuria/acute myeloid leukaemia; PNH/AML) occurred in 16%, 11% and 1% of mAA cases respectively. Of the mAA patients who received immunosuppressive therapy, 67% responded irrespective of time of initiation of therapy while conservatively managed patients showed no spontaneous remissions. Genomic analysis of mAA identified evidence of clonal haematopoiesis with both persisting and remitting patterns at low allelic frequencies; with more pronounced mutational burden in sAA. Most of the mAA patients have autoimmune pathogenesis similar to those with sAA, but mAA contains a mix of patients with diverse aetiologies. Although progression rates differed between mAA and sAA (P = 0·003), cumulative incidences of mortalities were only marginally different (P = 0·095). Our results provide guidance for diagnosis/management of mAA, a condition for which no current standard of care is established.

[A clinical study of haploidentical hematopoietic stem cell transplantation in the treatment of pediatric patients with acquired severe aplastic anemia: single center experience]

目的

探讨单倍型造血干细胞移植（haplo-HSCT）治疗儿童获得性重型再生障碍性贫血（SAA）的疗效。

方法

回顾性分析2011年12月1日至2017年12月1日接受haplo-HSCT的59例SAA患者。

结果

①全部59例SAA患儿中男37例、女22例，中位年龄4.5（1.2~14.8）岁，中位体重43（12~80）kg；SAA-Ⅰ型47例，SAA-Ⅱ型12例，26例为极重型再生障碍性贫血（VSAA）；首次移植56例，二次移植3例。②预处理选用白消安+环磷酰胺+抗胸腺细胞球蛋白（ATG）方案或白消安+氟达拉滨+环磷酰胺+ATG方案；采用环孢素A（CsA）+霉酚酸酯+甲氨蝶呤方案预防急性GVHD；回输单个核细胞中位数为15.60（7.74~21.04）×10⁸/kg，CD34⁺细胞中位数为4.86（3.74~7.14）×10⁶/kg。③全部59例患儿均获得中性粒细胞和血小板植入。中性粒细胞植入中位时间为13（10~19）d，血小板植入中位时间为19（9~62）d。④Ⅰ~Ⅱ、Ⅲ/Ⅳ度急性GVHD发生率分别为45.76%（27/59）、13.56%（8/59），慢性GVHD发生率为8.47%（5/59）。巨细胞病毒血症发生率为59.32%（35/59）、EB病毒血症发生率为28.81%（17/59）。⑤中位随访时间30（8~80）个月，57例无病存活，2例死亡（均死于GVHD），5年总生存率、无失败生存率均为（96.4±2.5）%。

结论

haplo-HSCT是儿童SAA疗效较好的治疗方法。

Evaluating the Efficacy and Anti-infective Effect of High-dose Intravenous Immunoglobulin Adjuvant Therapy for Acquired Aplastic Anemia Children

BACKGROUND

The efficacy and anti-infective effect of high-dose intravenous immunoglobulin (HDIVIG) in severe or very severe aplastic anemia children were evaluated.

PATIENTS AND METHODS

In total, 61 patients who underwent immunosuppressive therapy were retrospectively reviewed. The non-IVIG group (30 cases) received rabbit-antithymocyte protein (R-ATG, 3 to 5 mg/kg/d, for 5 consecutive days)+cyclosporin A (CSA), and the HDIVIG group (31 cases) underwent R-ATG+CSA+immunoglobulin (1 g/kg/d, for 2 consecutive days, once a month, 6 times).

RESULTS

The early effective rate was higher in the HDIVIG group (P=0.020). However, the long-term effective rate and the 5-year overall survival rates difference were not statistically significant (P=0.717, 0.419). The infection rate and severe infection rate in the HDIVIG group were lower (P=0.003, 0.008). The infection-related mortality differences were not statistically significant after ATG application (P>0.05). In the HDIVIG group, 9 patients were nonresponders. Among the nonresponders, 8 patients' first-dose IVIG was given within 7 days before ATG.

CONCLUSIONS

HDIVIG may increase the early effective rate and reduce early infection and serious infection for aplastic anemia children, but failed to reduce the infection-related mortality.

Upfront eltrombopag monotherapy induces stable hematologic remission in pediatric patients with nonsevere idiopathic aplastic anemia

Aplastic anemia (AA) is characterized by multilineage cytopenias and bone marrow hypocellularity. Severe AA can be treated with immunosuppressive therapy (IST) and/or allogeneic hematopoietic stem cell transplantation. The thrombopoietin agonist eltrombopag has been shown to induce hematopoietic recovery and transfusion independence in adults with refractory and relapsed AA. Recently, upfront eltrombopag therapy in patients with AA in combination with IST has shown efficacy. Data for its use without concurrent IST in pediatric patients with AA remain sparse. Here we report two pediatric patients with AA not meeting severe criteria who achieved hematologic response with upfront eltrombopag monotherapy.

Diagnosis and Treatment of Aplastic Anemia

OPINION STATEMENT

Acquired aplastic anemia (AA) is a rare, life-threatening bone marrow failure (BMF) disorder that affects patients of all ages and is caused by lymphocyte destruction of early hematopoietic cells. Diagnosis of AA requires a comprehensive approach with prompt evaluation for inherited and secondary causes of bone marrow aplasia, while providing aggressive supportive care. The choice of frontline therapy is determined by a number of factors including AA severity, age of the patient, donor availability, and access to optimal therapies. For newly diagnosed severe aplastic anemia, bone marrow transplant should be pursued in all pediatric patients and in younger adult patients when a matched sibling donor is available. Frontline therapy in older adult patients and in all patients lacking a matched sibling donor involves immunosuppressive therapy (IST) with horse antithymocyte globulin and cyclosporine A. Recent improvements in upfront therapy include encouraging results with closely matched unrelated donor transplants in younger patients and the emerging benefits of eltrombopag combined with initial IST, with randomized studies underway. In the refractory setting, several therapeutic options exist, with improving outcomes of matched unrelated donor and haploidentical bone marrow transplantation as well as the addition of eltrombopag to the non-transplant AA armamentarium. With the recent appreciation of frequent clonal hematopoiesis in AA patients and with the growing use of next-generation sequencing in the clinic, utmost caution should be exercised in interpreting the significance of somatic mutations in AA. Future longitudinal studies of large numbers of patients are needed to determine the prognostic significance of somatic mutations and to guide optimal surveillance and treatment approaches to prevent long-term clonal complications.

Long-term outcomes of 95 children with moderate aplastic anemia treated with horse antithymocyte globulin and cyclosporine

BACKGROUND

Currently, the standard management of moderate aplastic anemia (MAA) has not been well described, although the superiority of the combination of antithymocyte globulin (ATG) and cyclosporine (CyA) over CyA alone has been demonstrated in terms of hematological responses and failure-free survival (FFS).

PROCEDURE

We adopted this therapeutic strategy and treated 95 children with MAA who were enrolled in two consecutive prospective studies between October 1992 and August 2009.

RESULTS

For these patients, the 6-month response rate was 54.7% (complete response, 13.7%; partial response, 41.1%). There were no statistically significant differences in the overall response rates between the transfusion-dependent (48.8%, n = 41) and transfusion-independent groups (59.3%, n = 54; P = 0.4). Treatment failure was defined as the requirement of salvage treatment, and was observed in 52 patients. The 10-year FFS was 44.0% (95% confidence interval [CI], 32.9%-54.6%). Of the 22 patients who underwent a second immunosuppressive therapy (IST), 12 responded. Forty patients underwent hematopoietic stem cell transplantation as second- or third-line therapy and three died of complications. Consequently, the 10-year overall survival rate was 96.0% (95% CI, 88.0%-98.7%) with a median follow-up period of 103 months (range, 29-221 months).

CONCLUSIONS

Although current guidelines recommend only observation for patients with transfusion-independent MAA, the results of our study justify early intervention with ATG and CyA in those patients. A prospective randomized trial is warranted to clarify the risks and benefits of early intervention with IST and observation alone until progression to severe AA in patients with MAA.

[Treatment of transfusion-dependent nonsevere aplastic anemia with cyclosporine A plus ATG/ALG versus cyclosporine A plus androgens: a retrospective single center study]

Objective: To determine whether cyclosporine A (CsA) plus androgens was as effective as the current standard immunosuppressive therapy (IST) for transfusion-dependent nonsevere aplastic anemia (TD-NSAA). Methods: The records of 125 consecutive TD-NSAA patients who were treated between Aug. 2007 and Sept. 2014, with either CsA plus androgen or ALG/ATG plus CsA regimen were reviewed. The 3-month and 6-month hematologic responses and survival were evaluated. Results: There were 125 TD-NSAA patients (70 were male and 55 female, 1.25∶1). Median age was 27 (6-66) years. There was no significant difference in early mortality between 48 treated by ATG/ALG plus CsA and 77 by CsA plus androgen patients (1/48 vs 0/77, P=0.384). Both the total hematologic response and the better hematological response rates at 3-month (70.8% vs 45.5%, P=0.006 and 27.1% vs 10.4%, P=0.015, respectively) and 6-month (75.0% vs 55.8%, P=0.031 and 41.7% vs 22.1% P =0.020, respectively) after treatment were much higher in the standard IST group than that in CsA plus androgen group. The median time to transfusion independent of 36.5 (0-149) days in the standard IST group was significantly shorter than 98 (14-180) days in CsA plus androgen group (P<0.001). Survival was comparable between the two groups (97.9% vs 100.0%, P=0.227). It was superior (71.2% vs 59.5%) but not significantly (P=0.227) in event-free survival in standard IST group. Conclusions: CsA plus androgen was inferior to the standard IST of ATG/ALG and CsA regimen in treating TD-NSAA in terms of the hematologic response and the quality of response, despite of comparable short-term survival.

Acquired aplastic anemia in children

This article provides a practice-based and concise review of the etiology, diagnosis, and management of acquired aplastic anemia in children. Bone marrow transplantation, immunosuppressive therapy, and supportive care are discussed in detail. The aim is to provide the clinician with a better understanding of the disease and to offer guidelines for the management of children with this uncommon yet serious disorder.

First-line allogeneic hematopoietic stem cell transplantation of HLA-matched sibling donors compared with first-line ciclosporin and/or antithymocyte or antilymphocyte globulin for acquired severe aplastic anemia

BACKGROUND

Acquired severe aplastic anemia is a rare and potentially fatal disease, which is characterized by hypocellular bone marrow and pancytopenia. The major signs and symptoms are severe infections, bleeding, and exhaustion. First-line allogeneic hematopoietic stem cell transplantation (HSCT) of a human leukocyte antigen (HLA)-matched sibling donor (MSD) is a treatment for newly diagnosed patients with severe aplastic anemia. First-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin (as first-line immunosuppressive therapy) is an alternative to MSD-HSCT and is indicated for patients where no MSD is found.

OBJECTIVES

To evaluate the effectiveness and adverse events of first-line allogeneic hematopoietic stem cell transplantation of HLA-matched sibling donors compared to first-line immunosuppressive therapy including ciclosporin and/or antithymocyte or antilymphocyte globulin in patients with acquired severe aplastic anemia.

SEARCH METHODS

We searched the electronic databases MEDLINE (Ovid), EMBASE (Ovid), and The Cochrane Library CENTRAL (Wiley) for published articles from 1946 to 22 April 2013. Further searches included trial registries, reference lists of recent reviews, and author contacts.

SELECTION CRITERIA

The following prospective study designs were eligible for inclusion: randomized controlled trials (RCTs) and non-randomized controlled trials if the allocation of patients to treatment groups was consistent with 'Mendelian randomization'. We included participants with newly diagnosed severe aplastic anemia who received MSD-HSCT or immunosuppressive therapy without prior HSCT or immunosuppressive therapy, and with a minimum of five participants per treatment group. We did not apply limits on publication year or languages.

DATA COLLECTION AND ANALYSIS

Two review authors abstracted the data on study and patient characteristics and assessed the risk of bias independently. We resolved differences by discussion or by appeal to a third review author. The primary outcome was overall mortality. Secondary outcomes were treatment-related mortality, graft failure, no response to first-line immunosuppressive therapy, graft-versus-host-disease (GVHD), relapse after initial successful treatment, secondary clonal and malignant disease, health-related quality of life, and performance score.

MAIN RESULTS

We identified three trials that met the inclusion criteria. None of these trials was a RCT. 302 participants are included in this review. The three included studies were prospectively conducted and had features consistent with the principle of 'Mendelian randomization' as defined in the present review. All studies had a high risk of bias due to the study design. All studies were conducted more than 10 years ago and may not be applicable to the standard of care of today. Primary and secondary outcome data showed no statistically significant difference between treatment groups. We present results for first-line allogeneic hematopoietic stem cell transplantation of an HLA-matched sibling donor, which we denote as the MSD-HSCT group, versus first-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin, which we denote as the immunosuppressive therapy group in the following section.The pooled hazard ratio for overall mortality for the MSD-HSCT group versus the immunosuppressive therapy group was 0.95 (95% confidence interval 0.43 to 2.12, P = 0.90, low quality evidence). Therefore, overall mortality was not statistically significantly different between the groups. Treatment-related mortality ranged from 20% to 42% for the MSD-HSCT group and was not reported for the immunosuppressive therapy group (very low quality evidence). The authors reported graft failure from 3% to 16% for the MSD-HSCT group and GVHD from 26% to 51% (both endpoints not applicable for the immunosuppressive therapy group, very low quality evidence). The authors did not report any data on response and relapse for the MSD-HSCT group. For the immunosuppressive therapy group, the studies reported no response from 15% (not time point stated) to 64% (three months) and relapse in one of eight responders after immunosuppressive therapy at 5.5 years (very low quality evidence). The authors reported secondary clonal disease or malignancies for the MSD-HSCT group versus the immunosuppressive therapy group in 1 of 34 versus 0 of 22 patients in one study and in 0 of 28 versus 4 of 86 patients in the other study (low quality evidence). None of the included studies addressed health-related quality of life. The percentage of the evaluated patients with a Karnofsky performance status score in the range of 71% to 100% was 92% in the MSD-HSCT group and 46% in the immunosuppressive therapy group.

AUTHORS' CONCLUSIONS

There are insufficient and biased data that do not allow any conclusions to be made about the comparative effectiveness of first-line allogeneic hematopoietic stem cell transplantation of an HLA-matched sibling donor and first-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin (as first-line immunosuppressive therapy). We are unable to make firm recommendations regarding the choice of intervention for treatment of acquired severe aplastic anemia.

A promising immunosuppressive strategy of cyclosporine alternately combined with levamisole is highly effective for moderate aplastic anemia

The appropriate management of patients with moderate aplastic anemia (mAA) remains to be unclear and controversial. A cohort of 118 patients with mAA received a novel immunosuppressive strategy of cyclosporine alternately combined with levamisole (CSA and LMS regimen), which included 42 newly diagnosed and 76 chronic (disease duration >6 months) cases. CSA and LMS regimen was orally administrated with the initial dose of CSA 3 mg/kg per day in adults or 5 mg/kg per day in children, and LMS 150 mg per day in adults or 2.5 mg/kg per day in children, continued for 12 more months after achieving maximal hematologic response, followed by a slow tapering. The overall response rates were of 100 and 86.8 % for newly diagnosed and chronic group, respectively. The 24-month progression-free survival were 95.2 % (95 % confidence intervals [CI], 85.9-100 %) and 93.6 % (95 % CI, 86.9-100 %) for newly diagnosed and chronic group, respectively (P = 0.50). The 2-year event-free survival for the patients in newly diagnosed group (86.6 %; 95 % CI, 70.4-100 %) was superior to that in chronic group (57.0 %; 95 % CI, 43.5-70.4 %, P = 0.001). To date, 11 patients relapsed and no patients evolved to clonal disorders. Thus, CSA and LMS regimen represents a promising immunosuppressive strategy for mAA.

Moderate aplastic anemia in children: preliminary outcomes for treatment versus observation from a single-institutional experience

INTRODUCTION

Because of the variety of definitions used to describe moderate aplastic anemia (MAA), we review our institutional experience period with patients who met a proposed set of criteria for this disorder. On an exploratory basis, we sought to evaluate the influence of treatment with immunosuppressive therapy (IST) versus observation on long-term outcomes.

MATERIALS AND METHODS

Records from 1999 to 2010 were screened for patients who met the criteria for MAA: (1) bone marrow cellularity of 20% to 50%; (2) cytopenias in at least 1 cell line (absolute neutrophil count<1000/µL, hemoglobin<9 g/dL, platelet count<100,000/µL); (3) mean corpuscular volume ≥90; (4) persistence >6 months; and (5) negative Fanconi studies. Data were collected for patient/disease characteristics, treatments, and outcomes.

RESULTS

Eight patients met the criteria for MAA. Three of 8 patients received IST. Of 3 patients who received IST, complete response was observed in 2 and transfusion independence in 1, as compared with 2 of 5 and 3 of 5 in the group who were observed without IST. Median duration of follow-up was 48 months.

DISCUSSION

As several patients spontaneously resolved, and none developed severe aplastic anemia, acute myelogenous leukemia, or myelodysplastic syndrome, the criteria used here may identify a group of children with favorable prognosis who can be managed supportively.

The progression risk factors of children with transfusion-independent non-severe aplastic anemia

Non-severe aplastic anemia (NSAA) in children is a rare, idiopathic condition of bone marrow insufficiency that can resolve spontaneously, persist for months or years, or progress to severe aplastic anemia (SAA). We reviewed clinical and laboratory data of patients diagnosed with transfusion-independent non-severe aplastic anemia (NSAA) from 1996 to 2009 at the Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, and analyzed the clinical course and outcomes in these patients. NSAA was defined as bone marrow cellularity <50 % and two or three cytopenias that persisted for 6 weeks or more: absolute neutrophil count (ANC) <1.5 × 10(9)/L, absolute reticulocyte count (ARC) <40 × 10(9)/L, platelet count <100 × 10(9)/L, without meeting criteria for SAA (bone marrow cellularity <30 % and two or three cytopenias: ANC <0.5 × 10(9)/L, ARC <20 × 10(9)/L, platelet count <20 × 10(9)/L). All patients were treated with reasonable supportive care, cyclosporine A, and stanozolol (0.1 mg/kg/day). Of a total of 284 patients, 117 (41.2 %) were female, and 167 (58.8 %) were male. With a median follow-up of 43 months (range 2-196 months), 38 patients (13.4 %) progressed to transfusion-dependent NSAA and among them 26 patients (9.2 %) progressed to SAA. One hundred and ninety-eight patients (69.7 %) had persistent NSAA. Forty-eight patients (16.9 %) showed the complete resolution of NSAA. The Kaplan-Meier estimates of all patients for progression-free survival were 86 ± 2.7 % and 66 ± 7.3 % at 60 and 120 months after diagnosis, respectively. Patients with ANC <1.0 × 10(9)/L or female had a higher probability of progression to transfusion-dependent NSAA (18.5 vs. 5.4 %, respectively; p = 0.002, and 17.1 vs. 10.8 %, respectively; p = 0.022). The patients with ARC <60 × 10(9)/L or with ANC <1.0 × 10(9)/L had a higher probability of progression to SAA (11.5 vs. 3.6 %, respectively; p = 0.035, and 12.7 vs. 3.6 %, respectively; p = 0.011). A categorical risk factor analysis showed that patients with ANC <1 × 10(9)/L had a higher probability of progression to SAA (p = 0.03) and had a higher probability of progression to transfusion-dependent AA (p = 0.007). NSAA patients may be benefited from early intervention with cyclosporine A and stanozolol.

Vascular endothelial growth factor corrected for platelet count and hematocrit is associated with the clinical course of aplastic anemia in children

The wide variety of clinical courses that lead to the development of severe aplastic anemia (AA) makes it difficult to speculate whether treatment for AA is required in the early phase. The objective of this study was to identify a method for predicting the clinical course of AA at the onset of the disease. First, in healthy adults, vascular endothelial growth factor (VEGF) released per platelet was measured by the activation of platelet-rich plasma (PRP) and platelet-poor plasma (PPP). Serum concentration of VEGF, serum concentration of VEGF corrected for platelet count, and serum concentration of VEGF corrected for both platelet count and hematocrit (corrected VEGF) were then compared to VEGF released per platelet. Corrected VEGF showed the best correlation with VEGF released per platelet by the activation of PRP in healthy subjects (R (2) = in a single 0.806, p = 0.001). Next, corrected VEGF was assayed in 11 pediatric patients with AA at the time of diagnosis. Corrected VEGF in AA patients was significantly greater than that in age-matched control subjects [1.32 × 10(-6) pg (range 0.36-1.85) vs. 0.18 × 10(-6) pg (range 0.12-0.94)] (p = 0.002). Moreover, corrected VEGF in AA patients who did not require treatment for more than 2 years was significantly greater than that in AA patients who required earlier treatment [1.67 × 10(-6) pg (range 1.32-1.85) vs. 0.87 × 10(-6) pg (0.36-1.34)] (p = 0.011). These data indicate that a compensatory mechanism for increasing VEGF and preventing disease progression might play a role in AA. Corrected VEGF may be useful for predicting the clinical course of AA.

Relapse of aplastic anemia in children after immunosuppressive therapy: a report from the Japan Childhood Aplastic Anemia Study Group

BACKGROUND

Although the therapeutic outcome of acquired aplastic anemia has improved markedly with the introduction of immunosuppressive therapy using antithymocyte globulin and cyclosporine, a significant proportion of patients subsequently relapse and require second-line therapy. However, detailed analyses of relapses in aplastic anemia children are limited.

DESIGN AND METHODS

We previously conducted two prospective multicenter trials of immunosuppressive therapy for children with aplastic anemia: AA-92 and AA-97, which began in 1992 and 1997, respectively. In this study, we assessed the relapse rate, risk factors for relapse, and the response to second-line treatment in children with aplastic anemia treated with antithymocyte globulin and cyclosporine.

RESULTS

From 1992 to 2007, we treated 441 children with aplastic anemia with standard immunosuppressive therapy. Among the 264 patients who responded to immunosuppressive therapy, 42 (15.9%) relapsed. The cumulative incidence of relapse was 11.9% at 10 years. Multivariate analysis revealed that relapse risk was significantly associated with an immunosuppressive therapy regimen using danazol (relative risk, 3.15; P=0.001) and non-severe aplastic anemia (relative risk, 2.51; P=0.02). Seventeen relapsed patients received additional immunosuppressive therapy with antithymocyte globulin and cyclosporine. Eight patients responded within 6 months. Seven of nine non-responders to second immunosuppressive therapy received hematopoietic stem cell transplantation and five are alive. Eleven patients underwent hematopoietic stem cell transplantation directly and seven are alive.

CONCLUSIONS

In the present study, the cumulative incidence of relapse at 10 years was relatively low compared to that in other studies mainly involving adult patients. A multicenter prospective study is warranted to establish optimal therapy for children with aplastic anemia.

Clinical course of non-severe aplastic anemia in adults

The clinical course of non-severe aplastic anemia is variable, and risk factors related to disease progression are not well known. We reviewed clinical and laboratory data of the patients who were diagnosed with non-severe aplastic anemia from 1997 to 2007 at Seoul National University Hospital and analyzed the clinical course and outcomes in these patients. We defined non-severe aplastic anemia as hypocellular marrow with cytopenia in the peripheral blood, which does not meet the criteria for severe aplastic anemia (at least two of the following: ANC < 500/microl, platelet < 20,000/microl or reticulocyte < 20,000/microl). Among a total of 96 patients, 53 (55.2%) were male and the median age was 37.6 years old. As much as 41.7% (40) of the patients were initially asymptomatic. Sixty-two patients who were treated with oxymetholone, ATG/ALG, cyclosporin or other agents after initial diagnosis showed significantly lower levels of initial hemoglobin, red blood cell count and platelet count than those who did not receive any treatment. During the follow-up period, 18 patients progressed to severe aplastic anemia. Their median age was 29.9 years and the median progression time was 18 months. Initial white blood cell count and absolute neutrophil count in the evolution group tended to be lower than in the other group. The patients whose thrombocytopenia did not respond to treatment showed markedly higher frequency of progression to severe aplastic anemia. Treatment itself and responsiveness in reticulocyte and absolute neutrophil count were not correlated with their clinical courses. Sixteen patients showed overall improvement, whereas three patients developed secondary hematologic disease, acute myeloid leukemia, myelodysplastic syndrome and paroxysmal nocturnal hemoglobinuria. Non-severe aplastic anemia has a relatively indolent and mild clinical course. However, 18.8% of the study population progressed to severe disease. White blood cell and absolute neutrophil count at diagnosis and treatment responsiveness of thrombocytopenia were associated with disease progression. Careful monitoring and early management are needed for patients at risk.

The benefit of ATG in immunosuppressive therapy of children with moderate aplastic anemia

BACKGROUND

Previous studies specifically focused on the immunosuppressive therapy (IST) of children with moderate aplastic anemia (MAA) are rare. The aim of this study was to evaluate the advantage of using antithymocyte globulin (ATG) in the IST and its outcome of children with MAA.

METHODS

Forty-two children diagnosed with moderate aplastic anemia from 1993 to 2006 were retrospectively reviewed. Eighteen patients treated with ATG, cyclosporin A (CSA), and androgen are defined as the ATG group, the other 24 patients treated with CSA and androgen are defined as the non-ATG group. Survival and hematological response of the two groups were studied.

RESULTS

Response rate and transfusion-independent survival of the ATG group were both significantly higher than those of the non-ATG group (83.33 vs. 41.7%, p = .006; and 83.33 vs. 50%, p = .043, respectively). Compared with non-ATG group, fewer patients in ATG group progress to severe aplastic anemia (p = .03).

CONCLUSION

Immunosuppressive therapy including ATG benefits children with moderate aplastic anemia.

Acquired aplastic anemia in childhood

In comparison to past decades, children who have acquired aplastic anemia (AA) enjoy excellent overall survival that reflects improvements in supportive care, more accurate exclusion of children who have alternate diagnoses, and advances in transplantation and immunosuppressive therapy (IST). Matched sibling-donor hematopoietic stem cell transplants (HSCT) routinely provide long-term survival in the range of 90%, and 75% of patients respond to IST. In this latter group, the barriers to overall and complication-free survival include recurrence of AA, clonal evolution with transformation to myelodysplasia/acute myelogenous leukemia, and therapy-related toxicities. Improvements in predicting responses to IST, in alternative-donor HSCT, and in rationalizing therapy by understanding the pathophysiology in individual patients are likely to improve short- and long-term outcomes for these children.

Natural history of transfusion-independent non-severe aplastic anemia in children

Although the known clinical courses of non-severe aplastic anemia (NSAA) in children comprise spontaneous resolution, persistent NSAA, or progression to severe aplastic anemia (SAA), only a few published reports have indicated the outcome of transfusion-independent NSAA. We retrospectively evaluated the incidence and time of progression from transfusion-independent to transfusion-dependent NSAA or SAA. We reviewed the records of 70 children with acquired AA who were referred to our hospital between 1986 and 2006, and among them we found 22 patients who had transfusion-independent NSAA at diagnosis and were treated with supportive care alone until progression to transfusion-dependent AA. 22 patients were followed up for a median of 86 months (range, 11-198 months). The Kaplan-Meier estimates for progression-free survival were 62 +/- 12 and 22 +/- 13% at 60 and 120 months after diagnosis, respectively. None of the patients treated with supportive care alone improved hematologically. In conclusion, because the incidence of disease progression was high in patients with NSAA, a prospective randomized trial of early intervention with IST or observation alone until disease progression to SAA, followed by IST when the patients become transfusion-dependent is warranted.

Aplastic anemia

PURPOSE OF REVIEW

Most acquired aplastic anemia is the result of immune-mediated destruction of hematopoietic stem cells causing pancytopenia and an empty bone marrow, which can be successfully treated with either immunosuppressive therapy or hematopoietic stem-cell transplantation.

RECENT FINDINGS

In aplastic anemia, oligoclonally expanded cytotoxic T cells induce apoptosis of hematopoietic progenitors. T-bet, a transcription factor that binds to the interferon-gamma promoter region, is upregulated in aplastic anemia T cells. Regulatory T cells are significantly reduced in patients' peripheral blood and in an aplastic anemia murine model, infusion of regulatory T cells ameliorates disease progression. In a minority of cases, loss-of-function mutations in telomerase complex genes may underlie disease development. Long-term survival, once strongly linked to response to immunosuppressive therapy, can now be achieved even among nonresponders due to significant advances in supportive care and better salvage treatments.

SUMMARY

Evidence has accumulated in the recent years further corroborating an immune-mediated process underlying aplastic anemia pathogenesis. Hematopoietic stem-cell transplantation from a matched sibling donor is preferred for children and young adults with severe aplastic anemia, and immunosuppressive therapy is employed when hematopoietic stem-cell transplantation is not feasible due to age, lack of a histocompatible sibling, co-morbidities, or by patient choice.

An update on the management of severe idiopathic aplastic anaemia in children

The current outlook for a child with severe idiopathic aplastic anaemia (AA) is very much better than in previous decades. In part, this may reflect better differentiation of idiopathic and inherited marrow failure. For children with idiopathic AA and a human leucocyte antigen (HLA)-matched sibling donor (MSD), allogeneic haematopoietic stem-cell transplantation (AHSCT) is the primary therapy of choice, offering long-term disease-free survival of 90%, although graft-versus-host disease remains a cause of long-term morbidity. A greater treatment challenge remains for those children without a MSD. Combination immunosuppressive therapy (IST) is associated with response rates of 70% or more. However, relapse and clonal evolution with transformation to myelodysplasia or acute myeloid leukaemia remain significant problems after IST and long-term event-free survival rates are less impressive. For children who do not have a sustained response to IST, alternate donor AHSCT should be considered. New HLA typing technologies, novel stem cell sources, reduced-intensity conditioning and graft engineering have reduced toxicity and improved the outcome after alternate donor AHSCT. Emerging therapies that capitalise on recent advances in our understanding of the pathophysiology of idiopathic AA and the immunobiology of AHSCT and IST may further improve the long-term outcome of this disease.

Current concepts in the pathophysiology and treatment of aplastic anemia

Aplastic anemia, an unusual hematologic disease, is the paradigm of the human bone marrow failure syndromes. Almost universally fatal just a few decades ago, aplastic anemia can now be cured or ameliorated by stem-cell transplantation or immunosuppressive drug therapy. The pathophysiology is immune mediated in most cases, with activated type 1 cytotoxic T cells implicated. The molecular basis of the aberrant immune response and deficiencies in hematopoietic cells is now being defined genetically; examples are telomere repair gene mutations in the target cells and dysregulated T-cell activation pathways. Immunosuppression with antithymocyte globulins and cyclosporine is effective at restoring blood-cell production in the majority of patients, but relapse and especially evolution of clonal hematologic diseases remain problematic. Allogeneic stem-cell transplant from histocompatible sibling donors is curative in the great majority of young patients with severe aplastic anemia; the major challenges are extending the benefits of transplantation to patients who are older or who lack family donors. Recent results with alternative sources of stem cells and a variety of conditioning regimens to achieve their engraftment have been promising, with survival in small pediatric case series rivaling conventional transplantation results.

Quantitative analysis of bone marrow CD34 cells in aplastic anemia and hypoplastic myelodysplastic syndromes

Aplastic anemia (AA) and hypoplastic myelodysplastic syndromes (hMDS) are often difficult to distinguish. However, an accurate diagnosis is important because the prognosis and treatment of these diseases may differ. CD34+ hematopoietic progenitors are central to the pathogenesis of both disorders; they are the targets of the autoimmune attack in AA and neoplastic transformation in MDS. The aim of this study was to assess whether bone marrow CD34+ cell numbers could be used in differentiating between AA and hMDS. The percentage of bone marrow CD34+ cells was normal or increased (mean -3.5+0.5%, range 1-7%) in 15 of 35 patients studied, and low (mean -0.13 +/- 0.02%, range 0.02-0.36%) in 20 of 35 patients. All patients with a normal or increased percentage of CD34+ cells were ultimately diagnosed with hMDS based on the detection of clonal cytogenetic abnormalities or progression to refractory anemia with excess blasts/acute myeloid leukemia. All patients with low marrow CD34+ cell numbers met standard clinical criteria for AA and have not demonstrated neoplastic transformation with follow-up. Quantification of marrow CD34+ cells may serve as an important tool for distinguishing between AA and hMDS.

Diagnosis and treatment of children with aplastic anemia

BACKGROUND

Long-term survival rates among children diagnosed with severe aplastic anemia (SAA) are excellent due to the success of human leukocyte antigen (HLA)-identical related hematopoietic stem cell transplantation (HSCT), concurrent advances in immunosuppressive treatment (IST), and improved supportive care. The challenge in making treatment recommendations for children with SAA, therefore, is to balance the apparent chronicity and morbidity following IST, with the potential up-front toxicity and complications of HSCT.

METHODS

This review provides an update on the diagnosis and a risk-based treatment algorithm for children with acquired SAA. Recent experience using alternative donor HSCT and efforts to extend HSCT eligibility through advances in donor matching, de-escalation of conditioning regimens, and potential marrow graft engineering are highlighted. We discuss IST response rates, risks of relapse, and complications including clonal evolution.

CONCLUSIONS

While good treatment options exist for a majority of children diagnosed with SAA, novel non-transplantation treatments for unresponsive and relapsed patients without suitable transplant donors are needed. Further improvements in outcome will ultimately require a more complete understanding of the pathophysiology of aplastic anemia (AA).

Aplastic anaemia

Aplastic anaemia is a rare haemopoietic stem-cell disorder that results in pancytopenia and hypocellular bone marrow. Although most cases are acquired, there are unusual inherited forms. The pathophysiology of acquired aplastic anaemia is immune mediated in most cases; autoreactive lymphocytes mediate the destruction of haemopoietic stem cells. Environmental exposures, such as to drugs, viruses, and toxins, are thought to trigger the aberrant immune response in some patients, but most cases are classified as idiopathic. Similarly to other autoimmune diseases, aplastic anaemia has a varied clinical course; some patients have mild symptoms that necessitate little or no therapy, whereas others present with life-threatening pancytopenia representing a medical emergency. Paroxysmal nocturnal haemoglobinuria and myelodysplastic syndrome commonly arise in patients with aplastic anaemia, showing a pathophysiological link between these disorders. Acquired aplastic anaemia can be effectively treated by allogeneic bone-marrow transplantation, immunosuppression (generally antithymocyte globulin and ciclosporin), and high-dose cyclophosphamide.