Long-term outcome of pediatric patients with severe aplastic anemia treated with antithymocyte globulin and cyclosporine

Treatment of relapsed/refractory severe aplastic anemia in children: Evidence-based recommendations

Severe aplastic anemia (SAA) is a rare potentially fatal hematologic disorder. Although overall outcomes with treatment are excellent, there are variations in management approach, including differences in treatment between adult and pediatric patients. Certain aspects of treatment are under active investigation in clinical trials. Because of the rarity of the disease, some pediatric hematologists may have relatively limited experience with the complex management of SAA. The following recommendations reflect an up-to-date evidence-based approach to the treatment of children with relapsed or refractory SAA.

Efficacy, Safety, and Population Pharmacokinetics of Eltrombopag in Children with Different Severities of Aplastic Anemia

Eltrombopag was approved as a first-line treatment for patients older than 2 years old with severe aplastic anemia (SAA). However, data on eltrombopag in children with different types of aplastic anemia (AA), especially non-severe AA (NSAA), are limited. We performed a prospective, single-arm, and observational study to investigate eltrombopag's efficacy, safety, and pharmacokinetics in children with NSAA, SAA, and very severe AA (VSAA). The efficacy and safety were assessed every 3 months. The population pharmacokinetic (PPK) model was used to depict the pharmacokinetic profile of eltrombopag. Twenty-three AA children with an average age of 7.9 (range of 3.0-14.0) years were enrolled. The response (complete and partial response) rate was 12.5%, 50.0%, and 100.0% after 3, 6, and 12 months in patients with NSAA. For patients with SAA and VSAA, these response rates were 46.7%, 61.5%, and 87.5%. Hepatotoxicity occurred in one patient. Fifty-three blood samples were used to build the PPK model. Body weight was the only covariate for apparent clearance (CL/F) and volume of distribution. The allele-T carrier of adenosine triphosphate-binding cassette transporter G2 was found to increase eltrombopag's clearance. However, when normalized by weight, the clearance between the wild-type and variant showed no statistical difference. In patients with response, children with NSAA exhibited lower area under the curve from time zero to infinity, higher CL/F, and higher weight-adjusted CL/F than those with SAA or VSAA. However, the differences were not statistically significant. The results may support further individualized treatment of eltrombopag in children with AA.

Incidence of drug-related adverse events related to the use of high-alert drugs: A systematic review of randomized controlled trials

Background

High-alert medication (HAM) is more predictable to cause significant harm to the patient, even when used as intended. The damage related to the HAM lead not only suffering to the patient, but also raise the additional costs associated with care.

Objective

Evaluate the incidence of drug-related adverse events related to the use of high-alert medications.

Methods

It was conducted an active search for information through COCHRANE databases, LILACS, SciELO, SCOPUS, PubMed/MEDLINE and WEB OF SCIENCE. The search strategy included the following terms: "Patient safety", "Medication errors" and "Hospital" and "High Alert Medications" or "Dangerous Drugs" in different combinations. Then two reviewers independently conducted a preliminary evaluation of relevant titles, abstracts and finally full-text. Studies quality was evaluated according to PRISMA declaration.

Results

The systematic review evaluated seven articles, which showed that only 11 HAM identified in the literature could have serious events. The most frequently cited were warfarin (22.2%) which progressed from deep vein thrombosis to gangrene, suggesting lower initial doses, followed by cyclophosphamide (22.2%) and cyclosporine (22.2%) which presented invasive fungal infection and death. In addition to these, morphine was compared with its active metabolite (M6G), with M6G causing fewer serious clinical events related to nausea and vomiting, reducing the need for concomitant use of antiemetics.

Conclusions

The most reported drug classes in the articles included that were related to incidence of drug-related adverse events in use of high-alert medications: morphine, M6G-glucuronide, haloperidol, promethazine, ivabradine, digoxin, warfarin, ximelagatran, cyclophosphamide, cyclosporine, and ATG. The formulate protocols for the use of these medications, with importance placed on evaluating, among the classes, the medication that causes the least harm.

Eltrombopag combined with immunosuppressive therapy for pediatric severe aplastic anemia

BACKGROUND

Severe aplastic anemia (SAA) is caused by immune-mediated destruction. Standard immunosuppressive therapy (IST) is effective but needs to be improved.

METHODS

The data of patients with SAA and received IST were analyzed retrospectively to conducted this historical control study.

RESULTS

A total of 115 SAA patients (60 males; median age of 5.77 years and median follow-up time of 45 months) were enrolled in this study. The complete response rates (CRR) of the eltrombopag group at 3 and 6 months were higher than the control group (30.3% vs.8.2% at 3 months; 50.0% vs. 10.2% at 6 months). The overall response rates (ORR) showed no differences. There were significant differences in the times from G-CSF, Red blood cell transfusion, and Platelet transfusion between the two groups. No difference in overall survival (OS), event-free survival (EFS), and relapse rate between two groups. There is no variable were associated with prognosis in both groups.

CONCLUSION

Addition of eltrombopag to IST confers faster hematological response and higher early hematological response in pediatric SAA patients.

IMPACT

Addition of eltrombopag to standard immunosuppressive therapy confers faster hematological response and higher early hematological response in pediatric severe aplastic anemia patients. Eltrombopag showed reliable safety but had no impact on long-term response and prognosis. This article is a historical controlled study consisting of 115 pediatric severe aplastic anemia patients and makes up for the lack of clinical data deficient on pediatric severe aplastic anemia with TPO-RA combined with IST.

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

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

The long-term outcomes and safety of severe aplastic anemia treated with porcine antilymphocyte globulin plus cyclosporine, with or without thrombopoietin receptor agonists: a double-center retrospective study

BACKGROUND

Porcine antilymphocyte globulin (p-ALG) combined with cyclosporine (CsA) has been commonly used for severe aplastic anemia (SAA) patients, but few studies on the combination of p-ALG and thrombopoietin receptor agonist (TPO-RA).

RESEARCH DESIGN AND METHODS

We retrospectively analyzed the data of 85 people with diagnosed SAA who underwent p-ALG plus CsA, with or without TPO-RA from 2014 to 2023.

RESULTS

The overall response rates were 55.3% and 65.9% at 3 and 6 months, and the TPO-RA group were 66.7% and 72.3% at 3 and 6 months, without TPO-RA group were 27.8% and 55.6%. In multivariate analysis, baseline platelet count of > 10 × 109/L was a simple predictor of favorable response at 6 months (p = 0.015). The median follow-up time for all patients was 39 months (range 0.4 ~ 104), the 5-year overall survival (OS) rate was 90.6% [95% CI = 82.1-95.2%], and the failure-free survival (FFS) rate was 68.9% [95% CI = 56.6-78.4%]. Having hematologic responses in 6 months was an independent positive predictor for FFS (p = 0.000). Twelve patients (14.1%) suffered from serum sickness, and 9.5% of patients had mild hepatic impairment.

CONCLUSIONS

p-ALG along with CsA is an effective choice for patients with SAA. p-ALG combined with TPO-RA may contribute to the early restoration of hematopoiesis.

Progress in medical therapy in aplastic anemia: why it took so long?

The treatment of aplastic anemia (AA) has significantly advanced in the last 50 years, evolving from a fatal condition to one where survival rates now exceed 80-85%. Hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) have become the primary treatments, with the latter widely adopted due to factors like the scarcity of compatible donors, patient age, comorbidities, and limited HSCT access. A therapy breakthrough was the introduction of antithymocyte globulin (ATG), with its effectiveness further boosted by cyclosporine. However, it took years to achieve another major milestone in management. Initially, treatments aimed to intensify immunosuppression following the success of the ATG-cyclosporine combination, but these methods fell short of expectations. A major turning point was combining immunosuppression with stem cell stimulation, surpassing the efficacy of IST alone. Earlier, growth factors had shown limited success in AA treatment, but thrombopoietin receptor agonists represented a significant advancement. Initially applied alone as salvage, these were later combined with IST, forming the most effective current regimen for medically managing SAA. Horse ATG is the preferred formulation combined with cyclosporine and eltrombopag. This progress in AA treatment offers improved outcomes for patients afflicted with this once-lethal disease.

Relapse and transformation to myelodysplastic syndrome and acute myeloid leukemia following immunosuppressive therapy for aplastic anemia is more common as compared to allogeneic stem cell transplantation with a negative impact on survival

We studied the incidence of relapse, transformation to myelodysplastic syndrome/acute myeloid leukemia, and survival in patients with aplastic anemia (AA) surviving more than 1 year after ATG/ALG-based immunosuppressive therapy (IST) between 1985 and 2020. Four-hundred seventy patients (413 adults and 57 children) were studied, and data were compared with 223 patients who underwent matched sibling donor transplant (MSD HSCT). Median follow-up is 50 months (12-359). Relapse occurred in 21.9% at a median time of 33.5 months (5-228) post IST. Twenty-six (5.5%) patients progressed to PNH, while 20 (4.3%) evolved to MDS/AML. Ten-year estimated overall survival (OS) is 80.9 ± 3% and was significantly better in patients without an event (85.1 ± 4%) compared to relapse (74.6% ± 6.2%) or clonal evolution (12.8% ± 11.8%) (p = 0.024). While the severity of AA (p = 0.011) and type of ATG (p = 0.028) used predicted relapse, only age at IST administration influenced clonal evolution (p = 0.018). Among HSCT recipients, relapse rates were 4.9% with no clonal evolution, and the 10-year OS was 94.5 ± 2%. In patients who survived 1 year following IST, outcomes were good except with clonal evolution to MDS/AML. These outcomes, however, were still inferior compared to matched sibling donor HSCT.

Outcomes and risk factors of hemorrhagic cystitis in pediatric allogeneic hematopoietic stem cell transplantation recipients using different graft source and condition with severe aplastic anemia

BACKGROUND

Hemorrhagic cystitis (HC) is a severe complication of allo-HSCT, characterized by irritative symptoms of the urinary tract and a higher morbidity rate. The risk factors and prognosis of HC are still unclear.

OBJECTIVE

The objective of this study is to identify risk factors and outcomes to improve treatment in pediatric SAA patients undergoing HSCTs in the Children's Hospital of Soochow University.

METHODS

A total of 97 SAA patients as a cohort were enrolled from 2010 to 2019 in the Children's Hospital of Soochow University and a number of factors related to HC and outcomes were analysed. In all transplants (except UCBT), patients received a combination of G-CSF stimulated bone marrow (BM) and peripheral blood stem cell (PBSC). The minimum number of CD34 + cells is 5 × 10⁶ cells/kg.

RESULTS

Mononuclear cells dose (MNC, cut off: 8.53 × 10⁸/kg) and grade II-IV acute graft versus host disease (aGVHD) were identified as independent risk factors for HC. Patients without HC had better overall survival (OS) than with HC (No HC: 98.6%±1.4% vs HC: 87.4% ± 6.8%, p = 0.03).

CONCLUSION

We concluded that aGVHD and MNC dose in graft might play an important role in the development of HC in pediatric SAA patients undergoing allo-HSCT. HC is also a key complication affecting the prognosis of children with SAA after allo-HSCT.

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.

Matched related transplantation versus immunosuppressive therapy plus eltrombopag for first-line treatment of severe aplastic anemia: a multicenter, prospective study

This study prospectively compared the efficacy and safety between matched related donor-hematopoietic stem cell transplantation (MRD-HSCT) (n = 108) and immunosuppressive therapy (IST) plus eltrombopag (EPAG) (IST + EPAG) (n = 104) to determine whether MRD-HSCT was still superior as a front-line treatment for patients with severe aplastic anemia (SAA). Compared with IST + EPAG group, patients in the MRD-HSCT achieved faster transfusion independence, absolute neutrophil count ≥ 1.0 × 10⁹/L (P < 0.05), as well as high percentage of normal blood routine at 6-month (86.5% vs. 23.7%, P < 0.001). In the MRD-HSCT and IST + EPAG groups, 3-year overall survival (OS) was 84.2 ± 3.5% and 89.7 ± 3.1% (P = 0.164), whereas 3-year failure-free survival (FFS) was 81.4 ± 4.0% and 59.1 ± 4.9% (P = 0.002), respectively. Subgroup analysis indicated that the FFS of the MRD-HSCT was superior to that of the IST + EPAG among patients aged < 40 years old (81.0 ± 4.6% vs. 63.7 ± 6.5%, P = 0.033), and among patients with vSAA (86.1 ± 5.9% vs. 54.9 ± 7.9%, P = 0.003), while the 3-year OS of the IST + EPAG was higher than that of the MRD-HSCT among the patient aged ≥ 40 years old (100.0 ± 0.0% vs. 77.8 ± 9.8%, P = 0.036). Multivariate analysis showed that first-line MRD-HSCT treatment was associated favorably with normal blood results at 6-month and FFS (P < 0.05). These outcomes suggest that MRD-HSCT remains the preferred first-line option for SAA patients aged < 40 years old or with vSAA even in the era of EPAG.

Efficacy of eltrombopag with immunosuppressive therapy for children with acquired aplastic anemia

BACKGROUND

Eltrombopag (EPAG), an oral thrombopoietin receptor agonist (TPO-RA), has been proven to improve the hematologic response without increasing toxic effects as a first-line therapy combined with standard immunosuppressive treatment (IST) in adults with severe aplastic anemia (SAA). Nevertheless, the clinical evidence on the efficacy of EPAG in children with acquired aplastic anemia is limited and controversial.

METHODS

We performed a single-center, retrospective study to analyze the clinical outcomes of fifteen patients aged ≤18 years with newly diagnosed acquired SAA who received first-line IST and EPAG (EPAG group) compared with those of forty-five patients who received IST alone (IST group) by propensity score matching (PSM).

RESULTS

There was no difference in the overall response (OR) rate between the EPAG group and IST group (53.3% vs. 46.7% at 3 months, P = 0.655; 66.7% vs. 57.8% at 6 months, P = 0.543), but the complete response (CR) rate was statistically significant (20.0% vs. 4.4% at 3 months, P = 0.094; 46.7% vs. 13.3% at 6 months, P = 0.012). The median time to achieve a hematological response in the EPAG and IST groups was 105 days and 184 days, respectively. No difference was observed in the event-free survival (EFS) or overall survival (OS) rates.

CONCLUSION

Adding EPAG to standard IST as the first-line treatment for children with acquired SAA improved the rapidity of hematological response and the CR rate but did not improve the OR or EFS rates.

First-line haploidentical stem cell transplantation in children and adolescents with severe aplastic anemia using mobilized peripheral blood as source of CD34+: Single-institutional experience in a transplant center from northeast Mexico

INTRODUCTION

The only curative treatment for severe aplastic anemia in children is an allogeneic stem cell transplant; however, few patients have a matched related or unrelated donor. Haploidentical stem cell transplantation (haplo-SCT) using bone marrow (BM) and peripheral blood stem cells (PBSC) has been recently described as effective and safe. In this study, we retrospectively report the outcome of twelve pediatric patients who underwent haplo-SCT using only PBSC.

METHODS

The conditioning regimen consisted on rabbit anti-thymocyte globulin (r-ATG) 2.5 mg/kg/d on days -7, -6,-5, and -4, and cyclophosphamide (Cy) 50 mg/kg/d on days -3 and -2. We used Cy 50 mg/kg/d on days +3 and +4, tacrolimus and mycophenolic acid as graft versus host disease (GVHD) prophylaxis.

RESULTS

The median follow-up was 1,099 days (45-1258 days). The overall survival rate up-to-date is 83.3%. In 10 of the 12 patients, a sustained graft was achieved. None of the patients had acute or chronic GVHD.

CONCLUSIONS

Haplo-SCT could be established as a first-line treatment when there is no matched related or unrelated donor. According to this short sample and previous reports, PBSC are a feasible option effectively used as the sole source of stem cells. Additionally, post-transplant cyclophosphamide remains a good strategy for GVHD prevention.

Efficacy and safety of immunosuppressive therapy with or without eltrombopag in pediatric patients with acquired aplastic anemia: A Chinese retrospective study

To determine the efficacy and safety of eltrombopag (E-PAG) combined with intensive immunosuppressive therapy (IST) for the treatment of pediatric patients with severe aplastic anemia (SAA). A total of 57 pediatric patients with newly diagnosed severe aplastic anemia were enrolled in this study. Thirty nine patients were treated with IST alone, consisting of porcine anti-human thymocyte globulin (30 mg/kg/day × 5 days) and cyclosporine A (CsA) (treated for 2 years, with a trough concentration maintained at 200-250 ng/mL), and 18 patients were treated with IST + E-PAG (12.5-50 mg/day, maintained for 6 months). We found no statistical difference between the response rates at 3 months for the two groups (CR: 12.8% vs. 22.2% p > 0.05, ORR: 56.4% vs. 77.7% p > 0.05). However, we found a statistical difference between the response rates at 6 months for the two groups (CR: 17.9% vs. 50% p < 0.05, ORR: 69.2% vs. 94.4% p < 0.05). The main side-effect during treatment with E-PAG was having a slightly to moderately elevated bilirubin level, which was temporary and controllable, accounting for approximately 66.6% (12/18) of patients in the IST + E-PAG group vs. 20.5% (8/39) of those in the IST group (p < 0.05). IST + E-PAG therapy appears to be more effective than IST alone for the treatment of pediatric SAA, with good tolerability and compliance. This approach deserves further exploration.

Efficacy and safety of eltrombopag in the first-line therapy of severe aplastic anemia in children

Eltrombopag is being investigated for the treatment of aplastic anemia (AA) by stimulating hematopoietic stem cell (HSC) proliferation. To evaluate the efficacy and safety of eltrombopag in the first-line therapy of pediatric AA. The present retrospective study assessed pediatric patients with newly diagnosed AA administered immunosuppressive therapy (IST) (rabbit ATG combined with CSA) with eltrombopag at a single center from March to September 2017. All patients were followed up for >2 years. A total of 14 patients (8 males), averagely aged 86 months, were enrolled in this study. Eltrombopag was administered with a median time to initiation of 19.5 days after IST; the median course of treatment was 253 days. Complete and overall response rates at 6 months were 64.3% (9/14 case) and 78.6% (11/14 cases), respectively. The survival rate was 100%, and no relapse occurred in responders. Eltrombopag was well-tolerated; however, the most common adverse events included indirect bilirubin elevation, jaundice, and transient liver-enzyme elevation. By the end of follow-up, bone marrow chromosomes were normal, and no abnormal myelodysplastic syndrome (MDS)-related clones appeared. Addition of eltrombopag to IST is associated with markedly increased complete response with respect to hematology in pediatric patients with SAA compared with a historical cohort, without intolerable side effects.

Relationship between plasma rabbit anti-thymocyte globulin concentration and immunosuppressive therapy response in patients with severe aplastic anemia

OBJECTIVES

Patients with acquired aplastic anemia (AA) without HLA-matched sibling donors or aged >40 years receive immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG). We investigated the relationship between plasma rabbit ATG (r-ATG) concentration and IST response.

METHODS

From May 2012 to October 2017, 81 patients with severe AA who required initial IST were included. A 1:1 block randomization was employed for 2.5 and 3.5 mg/kg doses of r-ATG.

RESULTS

No significant difference in response rates was observed between the 2.5 and 3.5 mg/kg groups (63% vs. 58%, P = .894). Median r-ATG concentrations on days 14 and 28 after IST were 15.2 (0.0-97.7) and 1.8 (0.0-74.9 µg/mL), respectively. According to r-ATG concentration, response rates were significantly higher in the group with higher r-ATG concentration than in those with lower r-ATG concentration (day 14, 88% vs. 52%; P = .006 and day 28, 79% vs. 46%; P = .005). In multivariate analysis, higher r-ATG concentrations at day 28 were independent predictors of favorable response to IST at 6 months (odds ratio, 0.29; 95% confidence interval, 0.09-0.93; P = .037).

CONCLUSIONS

The present data indicate that higher r-ATG concentration at day 28 resulted in improved IST response.

Acquired severe aplastic anaemia: how medical therapy evolved in the 20th and 21st centuries

The progress in aplastic anaemia (AA) management is one of success. Once an obscure entity resulting in death in most affected can now be successfully treated with either haematopoietic stem cell transplantation (HSCT) or immunosuppressive therapy (IST). The mechanisms that underly the diminution of haematopoietic stem cells (HSCs) are now better elucidated, and include genetics and immunological alterations. Advances in supportive care with better antimicrobials, safer blood products and iron chelation have greatly impacted AA outcomes. Working somewhat 'mysteriously', anti-thymocyte globulin (ATG) forms the base for both HSCT and IST protocols. Efforts to augment immunosuppression potency have not, unfortunately, led to better outcomes. Stimulating HSCs, an often-sought approach, has not been effective historically. The thrombopoietin receptor agonists (Tpo-RA) have been effective in stimulating early HSCs in AA despite the high endogenous Tpo levels. Dosing, timing and best combinations with Tpo-RAs are being defined to improve HSCs expansion in AA with minimal added toxicity. The more comprehensive access and advances in HSCT and IST protocols are likely to benefit AA patients worldwide. The focus of this review will be on the medical treatment advances in AA.

Severe aplastic anaemia in children: Impact of histopathology profile and treatment on very long-term outcomes

AIM

To assess very long-term outcomes of children with severe aplastic anaemia (SAA) and impact of histopathology and of different treatments over time.

METHODS

We conducted a retrospective study of 57 consecutive patients with SAA during 1973-2019. According to period, treatment consisted of androgens, immunosuppressive treatment (IST) and haematopoietic cell transplantation (HCT) in 14, 31 and 13 patients, respectively. Histopathology immune profiles were studied on bone marrow (BM).

RESULTS

Response rate (RR) to androgens was 35%, with long-term survivorship in 4 of 5 responders. RR and 10-year overall survival (OS) after IST was 65% and 80%, respectively. RR was higher in girls (92% vs 43% in boys, P = .02). Mean baseline BM values of CD34 + and of B-lymphocytes in responders vs non-responders were 1.3% vs 0 (P = .08) and 14.1% vs 9.7% (P = .07), respectively. After IST, BM cellularity gradually increased and cytotoxic T-lymphocytes decreased (time variation P = .003 and 0.07, respectively). Outcome did not differ between patients with IST or frontline HCT. Ten-year OS improved over time, increasing from 35.3% to 77.1% and 77% during 1973-1985, 1986-2003 and 2004-2019, respectively.

CONCLUSION

Histopathology may refine response prediction to IST. The course of SAA in children, a previously fatal disease, was altered in recent times.

Pierre A, Shalhoub R, Wu CO, Townsley DM, Young NS. Eltrombopag added to immunosuppression for children with treatment-naïve severe aplastic anaemia

Acquired severe aplastic anaemia (SAA) has an immune pathogenesis, and immunosuppressive therapy (IST) with anti-thymocyte globulin and cyclosporine is effective therapy. Eltrombopag (EPAG) added to standard IST was associated with higher overall and complete response rates in patients with treatment-naïve SAA compared to a historical IST cohort. We performed a paediatric subgroup analysis of this trial including all patients aged <18 years who received EPAG plus standard IST (n = 40 patients) compared to a historical cohort (n = 87) who received IST alone. Response, relapse, clonal evolution, event-free survival (EFS), and overall survival were assessed. There was no significant difference in either the overall response rate (ORR) or complete response rate at 6 months (ORR 70% in EPAG group, 72% in historical group, P = 0·78). Adults (≥18 years) had a significantly improved ORR of 82% with EPAG compared to 58% historically (P < 0·001). Younger children had lower response rates than did adolescents. The trend towards relapse was higher and EFS significantly lower in children who received EPAG compared to IST alone. Addition of EPAG added to standard IST did not improve outcomes in children with treatment-naïve SAA. EPAG in the paediatric population should not automatically be considered standard of care. Registration: clinicaltrials.gov (NCT01623167).

Allogeneic hematopoietic stem cell transplantation in aplastic anemia: current indications and transplant strategies

Treatment options for newly diagnosed aplastic anemia (AA) patient includes upfront allogeneic hematopoietic stem cell transplant (HSCT) or immunosuppressive therapy (IST). With recent advances in supportive care, conditioning regimens and post-transplant immunosuppression the overall survival for HSCT approaches 70-90%. Transplant eligibility needs to be assessed considering age, comorbidities, donor availability and probability of response to immunosuppressive therapy (IST). Upfront HSCT should be offered to children and young adults with matched related donor (MRD). Upfront HSCT may also be offered to children and young adults with rapidly available matched unrelated donor (MUD) who require urgent HSCT. Bone marrow (BM) graft source and cyclosporine (CsA) plus methotrexate (MTX) as graft versus host disease (GVHD) prophylaxis are preferable when using anti-thymocyte globulin (ATG) based conditioning regimens. Alemtuzumab is an acceptable alternative to ATG and is used with CsA alone and with either BM or peripheral blood stem cells (PBSC). Cyclophosphamide (CY) plus ATG conditioning is preferable for patients receiving MRD transplant, while Fludarabine (Flu) based conditioning is reserved for older adults, those with risk factors of graft failure and those receiving MUD HSCT. For haploidentical transplant, use of low dose radiotherapy and post-transplant cyclophosphamide has resulted in a marked reduction in graft failure and GVHD.

Hepatitis-associated aplastic anemia in pediatric patients: single center experience

INTRODUCTION

Hepatitis-associated aplastic anemia is a rare type of acquired aplastic anemia that occurs after hepatitis. This study investigated cases with hepatitis-associated aplastic anemia.

METHODS

The files of patients with hepatitis-associated aplastic anemia who were followed up in our hospital between 2011-2019 were reviewed retrospectively.

RESULTS

A total of 15 patients with hepatitis-associated aplastic anemia (10 males, 5 girls; mean age 10.26 ± 3.61 years) were analyzed. The mean duration between hepatitis and aplastic anemia was 5.06 ± 4.19 months. The majority of patients had mild hepatitis. The causes of hepatitis were detected only in six patients: three had hepatitis B, one had hepatitis A, one had autoimmune hepatitis and, one had a hydatid cyst. The cause of hepatitis was not found in nine patients. Only one patient with hepatitis-associated aplastic anemia developed spontaneous remission, and the others required immunosuppressive therapy and/or hematopoietic stem cell transplantation. Only one patient died because of sepsis. The other patients are still under follow-up and treatment.

CONCLUSION

Patients with hepatitis-associated aplastic anemia, mostly of unknown cause, can be successfully treated with immunosuppressive therapy and/or hematopoietic stem cell transplantation.

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.

Efficacy and safety of porcine ALG compared to rabbit ATG as first-line treatment for children with acquired aplastic anemia

OBJECTIVE

To assess the outcomes of children with acquired aplastic anemia (AA) treated in China with first-line porcine anti-lymphocyte immunoglobulin (p-ALG)/rabbit anti-thymocyte immunoglobulin (r-ATG) combined with cyclosporine A (CSA).

METHODS

We performed a single-center, non-randomized, retrospective cohort study to assess the outcomes of 189 children with AA treated in China with first-line p-ALG/r-ATG combined with CSA between 2014 and 2018.

RESULTS

No significant differences were observed in the overall response rates at 3, 6, 12, or 24 months (3 months: 61.9% vs 67.4%, P = .5; 6 months: 70.9% vs 73.9%, P = .69; 12 months: 77.3% vs 73.3%, P = .58; 24 months: 81.6% vs 78.6%, P = .59) after either p-ALG- or r-ATG-based immunosuppressive therapy. No significant differences were observed in overall survival or failure-free survival between the p-ALG group and the r-ATG group.

CONCLUSION

Our results reveal that the therapeutic efficacy and safety of p-ALG combined with CSA did not differ significantly from those of r-ATG combined with CSA as first-line therapy for pediatric patients with AA. Moreover, p-ALG has the advantage of significantly lower cost compared with r-ATG.

[Alternative donor HSCT for 109 children with acquired severe aplastic anemia: a single center retrospective analysis]

Objective: To investigate the efficacy of alternative donor (AD) in the treatment of aplastic anemia (AA) in children. Methods: The clinical data of AA children who received AD HSCT in our center from Apr. 2010 to Dec. 2016 were retrospectively analyzed. The overall survival (OS) rate, implant success rate, incidence of acute and chronic graft-versus-host disease (GVHD) were statistically analyzed. Results: A total of 109 children with acquired AA, including 64 severe AA (SAA) , 32 very severe AA (VSAA) and 13 transfusion dependent non-severe AA (NSAA) , were recruited in this retrospective AD HSCT study, the median age was 6 (0.8-18) years old. Of them, 44 patients with 10/10 matched unrelated donor (MUD) , 44 patients with mismatched unrelated donor (MMUD) and 21 patients with mismatched related donor (MMRD) . All patients did not receive ATG before HSCT and the active infection was excluded. Except 3 patients suffered from a second graft failure (2 of them rescued by second HSCT) , 106/109 (97.2%) were engrafted with neutrophil and platelet recovery occurring at a median of 13 days (range, 9-19) and 16 days (range, 10-81) post-transplant. Until day 100 post transplantation, the incidence was 74.3% (81/109) for acute GVHD (aGVHD) and 39.4% (43/109) for grade Ⅱ-Ⅳ aGVHD, 30.7% (31/101) and 9.9% (10/101) for overall chronic GVHD (cGVHD) and moderate cGVHD, respectively, and nobody developed an extend cGVHD. After median follow up of 39 (0.7-103) months for all patients, 13 of 109 patients died. The estimated 5-year overall survival (OS) of the entire cohort was 88.1% (95%CI 81.1%-91.4%) with no difference among the MUD, MMUD and MMRD cohort (93.2%, 84.1% and 85.7%, respectively, P=0.361) . Conclusion: These excellent outcomes suggest that unmanipulated AD PBSC is a good HSCT source for children with SAA. It's reasonable to consider AD HSCT as first line therapy for SAA children without matched sibling donor. Better strategies are required to prevent GVHD.

Bone Marrow Failure in Children: Approach to Diagnosis and Treatment

Bone marrow failure has many different etiologies, including genetic defects which manifest with specific syndromes, as well as acquired conditions as a result of insults to the bone marrow leading to aplasia. The clinical picture is varied and clues for the underlying cause may or may not be evident at the time of presentation, frequently leading to a complex workup with a battery of tests often done to rule out genetic defects. The treatment approach for bone marrow failure is very dependent on the underlying cause, which makes it all the more critical to have an accurate diagnosis. First line management essentially consists of either hematopoietic stem cell transplant or immunosuppressive therapy. In this review authors will provide a broad look at the causes of bone marrow failure, the stepwise diagnostic algorithm and the approach to decision making for treatment. Fine details of each cause, and of each treatment modality are beyond the scope of this review which aims to provide an overview.

Impact of ABO incompatibility on outcomes after haploidentical hematopoietic stem cell transplantation for severe aplastic anemia

The impact of ABO incompatibility on transplantation outcomes in severe aplastic anemia (SAA) patients receiving haploidentical hematopoietic stem cell transplantation (HSCT) remains controversial without published data. A total of 199 SAA patients receiving haploidentical HSCT from ABO-matched (n = 114), minor ABO-incompatible (n = 47), or major ABO-incompatible donors (n = 38) were included in this study. The median time and cumulative incidences of both myeloid and platelet engraftment in the ABO-compatible and ABO-incompatible groups were similar, and pure red cell aplasia was absent. Minor ABO incompatibility increased the rate of grade III-IV acute graft-versus-host disease (aGVHD) (ABO compatible: 6.14 ± 0.05%, minor incompatible: 19.15 ± 0.34%, and major incompatible: 10.53 ± 0.25%; P = 0.051), but did not influence the rates of grade II-IV aGVHD or chronic GVHD (cGVHD). Minor ABO-incompatibility was identified as an independent risk factor for grade III-IV aGVHD by multivariate analysis (hazard ration (HR) = 4.00 (1.48-10.80), P = 0.006). Chronic GVHD, mortality, and treatment failure were not increased in the minor ABO-incompatible group. For SAA patients receiving haploidentical HSCT, ABO compatible donors are better than ABO minor incompatible donors if several haploidentical donors are available.

Patient features and survival of pediatric aplastic anemia in the USA: a large institution experience

BACKGROUND

We performed the first epidemiologic investigation to examine association of demographics and clinical characteristics at diagnosis, as well as health care expense coverage, with survival of US children with aplastic anemia (AA).

METHODS

We obtained electronic medical record data of 1140 children aged 0-19 years diagnosed with AA followed at a pediatric health system between 2004 and 2014. Kaplan-Meier curve and Cox proportional hazards regressions were used.

RESULTS

Self-pay patients had a mortality risk five times higher than that of those insured by publicly funded insurance (hazards ratio, 95% CI: 6.0, 3.7-9.8). Other features associated with higher mortality risk include pancytopenia (hazards ratio, referent: 4.2, constitutional AA); underweight (2.0, normal-weight); platelet count <50 × 109/l (1.3, ≥50 × 109/l); male sex (1.3, female); and ages at diagnosis 6-11, 11-16 and 16-19 years (1.6, 1.9, 2.3, 1-3 years), respectively.

CONCLUSIONS

Self-pay was the strongest prognostic factor for pediatric AA mortality. Older age, pancytopenia, underweight, male sex and lower platelet count were also associated with increased risk of mortality. These findings may be useful for providers, researchers and policymakers to ensure effective health care delivery to this population and to motivate future etiologic research and establishment of a surveillance registry.

Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study

Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia for pediatric patients is also limited. The clinical features and outcomes for 314 children treated from 2002 to 2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin (hATG) plus cyclosporine (CyA) with a median 61 months follow up. Following hATG/CyA, 71.2% (95%CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response achieved in pediatric patients was high, with 59.8% (95%CI: 53.7,65.8) complete response and 68.2% (95%CI: 62.2,73.8) achieving at least a very good partial response with a platelet count ≥50×10⁹L. At five years post-hATG/CyA, overall survival was 93% (95%CI: 89,96), but event-free survival without subsequent treatment was only 64% (95%CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis after a median 25.2 months (range: 4.3-71 months) post treatment. Myelodysplastic syndrome or leukemia developed in 6 of 314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95%CI: 0.08,0.47; P=0.0003). This study highlights the need for improved therapies to achieve sustained high-quality remission for children with severe aplastic anemia.

Updated Guidelines for the Treatment of Acquired Aplastic Anemia in Children

PURPOSE OF REVIEW

This review aimed to provide updated guidelines for the management of children with acquired aplastic anemia (AA), particularly focusing on hematopoietic stem cell transplantation (HSCT).

RECENT FINDINGS

Failure-free survival for children with aplastic anemia has been shown to be better after bone marrow transplantation (BMT) from matched or one-locus mismatched related donors (MRD/1MMRD) than after immunosuppressive therapy (IST). A combination of the absence of minor paroxysmal nocturnal hemoglobinuria clones and short telomere length was identified as a strong predictor of a poor response to IST. Upfront HSCT from matched unrelated donors (MUD) and MRD was recently demonstrated to have comparable outcomes. Moreover, unrelated cord blood transplantation (UCBT) and haploidentical HSCT have shown promising outcomes, and the fludarabine/melphalan-based regimen has resulted in excellent survival without poor graft function. BMT from MRD/1MMRD is the treatment of choice. When a MRD/1MMRD is not available, upfront BMT from a MUD should be considered for patients with only a slim chance of responding to IST. UCBT and haploidentical HSCT are promising options. This updated treatment algorithm should improve overall outcomes for children with AA.

Recent Advances and Long-Term Results of Medical Treatment of Acquired Aplastic Anemia: Are Patients Cured?

Horse antithymocyte globulin plus cyclosporine remains standard immunosuppressive therapy in severe aplastic anemia, with hematologic response rates of 60% to 70%. In those refractory to this regimen, a second course of therapy with rabbit antithymocyte globulin plus cyclosporine or alemtuzumab produces responses in 30% to 40%. Eltrombopag, a thrombopoietin receptor agonist, showed activity as a single agent in those refractory to initial immunosuppression with hematologic response rates of 40% to 50%. When combined with immunosuppression as frontline therapy, eltrombopag increased the rate of overall and complete response rates. Longer follow-up is needed to better define these outcomes.

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.

Eltrombopag Added to Standard Immunosuppression for Aplastic Anemia

BACKGROUND

Acquired aplastic anemia results from immune-mediated destruction of bone marrow. Immunosuppressive therapies are effective, but reduced numbers of residual stem cells may limit their efficacy. In patients with aplastic anemia that was refractory to immunosuppression, eltrombopag, a synthetic thrombopoietin-receptor agonist, led to clinically significant increases in blood counts in almost half the patients. We combined standard immunosuppressive therapy with eltrombopag in previously untreated patients with severe aplastic anemia.

METHODS

We enrolled 92 consecutive patients in a prospective phase 1-2 study of immunosuppressive therapy plus eltrombopag. The three consecutively enrolled cohorts differed with regard to the timing of initiation and the duration of the eltrombopag regimen (cohort 1 received eltrombopag from day 14 to 6 months, cohort 2 from day 14 to 3 months, and cohort 3 from day 1 to 6 months). The cohorts were analyzed separately. The primary outcome was complete hematologic response at 6 months. Secondary end points included overall response, survival, relapse, and clonal evolution to myeloid cancer.

RESULTS

The rate of complete response at 6 months was 33% in cohort 1, 26% in cohort 2, and 58% in cohort 3. The overall response rates at 6 months were 80%, 87%, and 94%, respectively. The complete and overall response rates in the combined cohorts were higher than in our historical cohort, in which the rate of complete response was 10% and the overall response rate was 66%. At a median follow-up of 2 years, the survival rate was 97%; one patient died during the study from a nonhematologic cause. Marked increases in bone marrow cellularity, CD34+ cell number, and frequency of early hematopoietic progenitors were noted. Rates of relapse and clonal evolution were similar to our historical experience. Severe rashes occurred in two patients, resulting in the early discontinuation of eltrombopag.

CONCLUSIONS

The addition of eltrombopag to immunosuppressive therapy was associated with markedly higher rates of hematologic response among patients with severe aplastic anemia than in a historical cohort. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT01623167 .).

Post-therapeutic recovery of serum interleukin-35 level might predict positive response to immunosuppressive therapy in pediatric aplastic anemia

BACKGROUND

The predictive value of interleukin-35 (IL-35) on efficacy of immunosuppressive therapy (IST) in aplastic anemia (AA) has not been well investigated. The aim of the study was to evaluate the association between serum IL-35 level and response to IST in pediatric AA.

METHODS

A total of 154 children with AA and 154 controls were included between January 2012 and December 2013. Blood and bone marrow fluid specimens were collected. Serum level of IL-35 was determined by enzyme-linked immunosorbent assay. Patients were treated with IST, and response to therapy was evaluated during 180-day follow-up period after starting therapy.

RESULTS

Serum levels of IL-35 at admission decreased significantly in patients compared with that in controls (10.9 ± 5.5 pg ml^-1 and 45.3 ± 8.8 pg ml^-1, p < 0.001). After starting IST, serum levels of IL-35 in patients recovered 30.7 ± 9.7 pg ml^-1 in the first 28 days (p < 0.001). During the follow-up period, increased range of serum IL-35 level ≥30.7 pg ml^-1 in the first 28 days was associated with effective response to therapy (odds ratio 7.97, 95% confidence interval 3.82-16.79). In addition, Fas/FasL protein expression in bone marrow mononuclear cells dropped significantly in the same group of patients in the first 28 days (p < 0.05).

CONCLUSION

The study revealed that post-therapeutic recovery of circulating IL-35 concentration might be an independent predictor for effective response to IST in pediatric AA. Moreover, apoptosis might be involved in such a forecasting process.

Upfront haploidentical transplant for acquired severe aplastic anemia: registry-based comparison with matched related transplant

BACKGROUND

Haploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) is an alternative treatment method for severe aplastic anemia (SAA) patients lacking suitable identical donors and those who are refractory to immunosuppressive therapy (IST). The current study evaluated the feasibility of upfront haploidentical HSCT in SAA patients.

METHODS

We conducted a multicenter study based on a registry database. One hundred fifty-eight SAA patients who underwent upfront transplantation between June 2012 and September 2015 were enrolled.

RESULTS

Eighty-nine patients had haploidentical donors (HIDs), and 69 had matched related donors (MRDs) for HSCT. The median times for myeloid engraftment in the HID and MRD cohorts were 12 (range, 9-20) and 11 (range, 8-19) days, with a cumulative incidence of 97.8 and 97.1% (P = 0.528), respectively. HID recipients had an increased cumulative incidence of grades II-IV acute graft-versus-host disease (aGVHD) (30.3 vs. 1.5%, P < 0.001), grades III-IV aGVHD (10.1 vs. 1.5%, P = 0.026), and chronic GVHD (cGVHD) (30.6 vs. 4.4%, P < 0.001) at 1 year but similar extensive cGVHD (3.4 vs. 0%, P = 0.426). The three-year estimated overall survival (OS) rates were 86.1 and 91.3% (P = 0.358), while the three-year estimated failure-free survival (FFS) rates were 85.0 and 89.8% (P = 0.413) in the HID and MRD cohorts, respectively. In multivariate analysis, survival outcome for the entire population was significantly adversely associated with increased transfusions and poor performance status pre-SCT. We did not observe differences in primary engraftment and survival outcomes by donor type.

CONCLUSIONS

Haploidentical SCT as upfront therapy was an effective and safe option for SAA patients, with favorable outcomes in experienced centers.

Nontransplant therapy for bone marrow failure

Nontransplant therapeutic options for acquired and constitutional aplastic anemia have significantly expanded during the last 5 years. In the future, transplant may be required less frequently. That trilineage hematologic responses could be achieved with the single agent eltrombopag in refractory aplastic anemia promotes new interest in growth factors after years of failed trials using other growth factor agents. Preliminary results adding eltrombopag to immunosuppressive therapy are promising, but long-term follow-up data evaluating clonal evolution rates are required before promoting its standard use in treatment-naive disease. Danazol, which is traditionally less preferred for treating cytopenias, is capable of preventing telomere attrition associated with hematologic responses in constitutional bone marrow failure resulting from telomere disease.

High-dose Cyclophosphamide is Effective Therapy for Pediatric Severe Aplastic Anemia

OBJECTIVE

Use of high-dose cyclophosphamide without hematopoietic stem cell transplant to treat severe aplastic anemia (SAA) has been controversial due to concern for increased infectious toxicity as compared with antithymocyte globulin and cyclosporine A. As children often tolerate dose-intensive therapy better than adults, we sought to perform a detailed retrospective analysis of both treatment response and toxicity in 28 patients younger than 22 years of age treated with 29 courses of high-dose cyclophosphamide as the sole form of immunosuppression.

STUDY DESIGN

Children and adolescents with SAA who lacked an human leukocyte antigen-matched sibling donor were treated with cyclophosphamide 50 mg/kg/d for 4 consecutive days then received daily granulocyte colony stimulating factor until neutrophil recovery, transfusion support, and antimicrobial prophylaxis.

RESULTS

Overall survival was 85%, with hematologic response of 79% and complete response of 66%. Cumulative incidences of bacterial infection (86%) and fungal infection (62%) were high but deaths due to infection were rare, as were clonal evolution (1/28), clinically relevant paroxysmal nocturnal (1/28), and relapse (2/28).

CONCLUSIONS

Response rates and survival following high-dose cyclophosphamide in pediatric patients with SAA exceed those seen in adults and compare favorably to antithymocyte globulin/cyclosporine A with manageable infectious toxicity.

Immunosuppressive therapy versus alternative donor hematopoietic stem cell transplantation for children with severe aplastic anemia who lack an HLA-matched familial donor

We compared the outcomes of immunosuppressive treatment (IST) with those of alternative donor hematopoietic stem cell transplantation (HSCT) in children and adolescents with severe aplastic anemia (SAA). The medical records of 42 patients with SAA who received frontline IST (N=19) or frontline HSCT with an alternative donor (N=23) between 1998 and 2012 were analyzed retrospectively. Six patients responded in the frontline IST group, whereas 11 underwent salvage HSCT after IST failure. Twenty-one of 23 patients who underwent frontline HSCT survived without treatment failure. The estimated failure-free survival rate of the frontline HSCT group was higher than that of the frontline IST group (91.3% vs 30.7% respectively, P<0.001). Six of 11 patients who underwent salvage HSCT experienced event-free survival (EFS). The estimated EFS of the frontline HSCT group was higher than that of the salvage HSCT group (91.3% vs 50.9% respectively, P=0.015). The outcome of alternative donor HSCT was better than commonly reported rates, especially in patients who underwent frontline HSCT. These results suggest that frontline alternative donor HSCT may be a better treatment option than IST for children and adolescents with SAA who lack a human leukocyte Ag-matched familial donor.

Higher plasma bilirubin predicts veno-occlusive disease in early childhood undergoing hematopoietic stem cell transplantation with cyclosporine

AIM: To analyze the association between plasma bilirubin levels and veno-occlusive disease (VOD) in non-adult patients undergoing hematopoietic stem cell transplantation (HSCT) during cyclosporine therapy.

METHODS: A total of 123 patients taking cyclosporine were evaluated using an electronic medical system at the Seoul National University Children’s Hospital from the years 2004 through 2011. Patients were grouped by age and analyzed for incidence and type of adverse drug reactions (ADRs) including VOD.

RESULTS: The HSCT patients were divided into three age groups: G#1 ≥ 18; 9 ≤ G#2 ≤ 17; and G#3 ≤ 8 years of age). The majority of transplant donor types were cord blood transplantations. Most prevalent ADRs represented acute graft-vs-host disease (aGVHD) and VOD. Although the incidences of aGVHD did not vary among the groups, the higher frequency ratios of VOD in G#3 suggested that an age of 8 or younger is a risk factor for developing VOD in HSCT patients. After cyclosporine therapy, the trough plasma concentrations of cyclosporine were lower in G#3 than in G#1, indicative of its increased clearance. Moreover, in G#3 only, a maximal total bilirubin level (BILmax) of ≥ 1.4 mg/dL correlated with VOD incidence after cyclosporine therapy.

CONCLUSION: HSCT patients 8 years of age or younger are more at risk for developing VOD, diagnosed as hyperbilirubinemia, tender hepatomegaly, and ascites/weight gain after cyclosporine therapy, which may be represented by a criterion of plasma BILmax being ≥ 1.4 mg/dL, suggestive of more sensitive VOD indication in this age group.

Biomarkers for predicting clinical response to immunosuppressive therapy in aplastic anemia

The decision to select hematopoietic stem cell transplantation (HSCT) or immunosuppressive therapy (IST) as initial therapy in acquired aplastic anemia (AA) is currently based on patient age and the availability of a human leukocyte antigen (HLA)-matched donor. Although IST is a promising treatment option, the ability to predict its long-term outcomes remains poor due to refractoriness, relapses, and the risk of clonal evolution. Several predictive biomarkers for response to IST have been posited, including age, gender, pre-treatment blood cell counts, cytokines, gene mutations, paroxysmal nocturnal hemoglobinuria (PNH), and telomere length (TL). While previous studies have provided substantial biological insights into the utility of IST, the prognostic power of the reported biomarkers is currently insufficient to contribute to clinical decision making. Recently, a large retrospective analysis proposed the combination of minor PNH clones and TL as an efficient predictor of IST response. Identification of a reliable predictor would provide a useful tool for determining the most appropriate treatment choice for AA patients, including up-front HSCT from HLA-matched unrelated donor. The present review summarizes studies evaluating the utility of biomarkers in predicting the clinical response to IST of patients with AA, and provides a baseline for prospective studies aimed at validating previously reported biomarkers.

Markedly High Plasma Thrombopoietin (TPO) Level is a Predictor of Poor Response to Immunosuppressive Therapy in Children With Acquired Severe Aplastic Anemia

BACKGROUND

Immunosuppressive therapy (IST) is commonly used for patients with acquired severe aplastic anemia (SAA). Because the clinical response rate and therapeutic outcome for individual patients to IST varies, an in vitro test that identifies potential responders would be desirable.

METHODS

We evaluated the relationship between thrombopoietin (TPO) levels at the time of diagnosis and the response to IST at 6 months in 85 children (median age, 9.0 years; range, 1.0-15.5 years) with acquired SAA using enzyme-linked immunosorbent assay. Thirty-one age-matched healthy individuals were used as controls. All patients received antithymocyte globulin and cyclosporine.

RESULTS

Overall, 39 patients (45.9%) responded to IST at 6 months. TPO plasma levels were significantly higher in nonresponders than in responders (1,555.8 vs. 1,284.7 pg/ml, respectively; P = 0.031). Multivariate analysis identified the TPO levels of >1,796.7 pg/ml (TPO-high group, 20 patients; odds ratio (OR), 8.285; 95% confidence interval (CI), 2.114-32.904; P = 0.002) as independent poor predictors of IST response at 6 months. Moreover, the TPO-high group was associated with lower 5-year failure-free survival rates (30% vs. 68%, P = 0.012) compared with the TPO-low group.

CONCLUSION

The measurement of TPO levels at diagnosis is useful for predicting the response to IST in children with SAA and may help in decision making.