Long-term outcome of acquired aplastic anaemia in children: comparison between immunosuppressive therapy and bone marrow transplantation

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.

Outcome of peripheral blood allogeneic hematopoietic stem cell transplantation as a treatment option in patients with severe aplastic anemia between 40 and 50 years

The frontline treatment for patients younger than 40 years with severe aplastic anemia (AA) is allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-identical sibling donor. However, in patients with severe AA who are older than 40 years, allogeneic HSCT has been found to be associated with increased treatment-related mortality and toxicity, even when matched sibling donors are used. We report our institutional experience with allogeneic HSCT in patients with severe AA between 40 and 50 years. A total of 19 patients with severe AA were included in the study. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. The mean age of patients at the time of transplant was 43.79 years, and 57.9% were male. The mortality rate was 36.8%, attributed to infection (10.5%), relapse (15.8%), and renal failure (5.3%) in all cases. Acute graft-versus-host disease (GVHD) occurred in five patients (26.3%), and chronic GVHD occurred in two patients (10.5%). The 5-year OS was 62% and the 5-year DFS was 52%. We found that the patient's age, platelet level prior to transplantation, and the number of CD3 cells infused for each transplant were independent prognostic factors for OS, and the age and sex of the patient, graft rejection, and platelet level prior to transplantation were significant prognostic factors associated with DFS. We recommend that immunosuppressive therapy be considered as a first-line treatment in patients with severe AA who are older than 40 years. Allogeneic HSCT can be considered a valid alternative option in patients whose suppression therapy fails.

Allo-HSCT compared with immunosuppressive therapy for acquired aplastic anemia: a system review and meta-analysis

Background

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) and immunosuppressive therapy (IST) are two major competing treatment strategies for acquired aplastic anemia (AA). Whether allo-HSCT is superior to IST as a front-line treatment for patients with AA has been a subject of debate. To compare the efficacy and safety of allo-HSCT with that of IST as a front-line treatment for patients with AA, we performed a meta-analysis of available studies that examined the impact of the two major competing treatment strategies for AA.

Results

Fifteen studies including a total of 5336 patients were included in the meta-analysis. The pooled hazard ratio (HR) for overall survival (OS) was 0.4 (95% CI 0.074–0.733, P = 0.016, I² = 58.8%) and the pooled HR for failure-free survival (FFS) was 1.962 (95% CI 1.43–2.493, P = 0.000, I² = 0%). The pooled relative risk (RR) for overall response rate (ORR) was 1.691 (95% CI 1.433–1.996, P = 0.000, I² = 11.6%).

Conclusion

Although survival was significantly longer among AA patients undergoing first-line allo-HSCT compared to those undergoing first-line IST, the selection of initial treatment for patients with newly diagnosed AA still requires comprehensive evaluation of donor availability, patient age, expected quality of life, risk of disease relapse or clonal evolution after IST, and potential use of adjunctive eltrombopag.

Aplastic Anemia Preconditioned with Fludarabine, Cyclophosphamide, and Anti-Thymocyte Globulin

Background

Graft rejection and graft versus host disease (GvHD) have impeded the success of hematopoietic cell transplantation for severe aplastic anemia (SAA) patients. There is no sufficient data to identify the outcomes of peripheral blood stem cell transplantation (PBSCT) in SAA patients, especially for adult SAA patients. The aim of this study was to evaluate the outcomes of adult SAA patients undergoing PBSCT with the FCA regimen. The FCA regimen includes fludarabine, cyclophosphamide, and anti-thymocyte globulin (ATG).

Material/Methods

We report our experience with 46 adult SAA patients who underwent PBSCT with the FCA regimen. Thirty SAA patients who received only cyclophosphamide and ATG (CA) regimen were used as controls. Complications and survival outcomes were evaluated and compared.

Results

There was a significantly higher percentage of patients who achieved >95% donor chimerism by day 30 in the FCA group. The 5-year event-free survival (EFS) rate in the FCA group was higher than that in the CA group (95.4% versus 73.3%). In addition, the 5-year rejection rate (RR) in the FCA group was lower than that in the CA group (4.6% versus 23.6%). A multivariable model identified the FCA regimen as an independent factor affecting EFS and RR. However, GvHD and serious infection did not differ between the 2 groups. For patients with an unrelated donor, the FCA regimen had a higher EFS and a lower RR than the CA regimen.

Conclusions

The FCA regimen for PBSCT in adult SAA patients compared favorably to the CA regimen. It can improve EFS and reduce graft rejection, especially for unrelated donor PBSCT.

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.

First-line choice for severe aplastic anemia in children: Transplantation from a haploidentical donor vs immunosuppressive therapy

We retrospectively compared the outcomes of children with severe aplastic anemia (SAA) who received immunosuppressive therapy (IST) or who underwent hematopoietic stem cell transplantation (HSCT) from a haploidentical donor (HID), between 2007 and 2016. A total of 52 children with SAA under the age of 17 years were initially treated with IST (n = 24) or haploidentical HSCT (n = 28) as first-line treatment. The estimated 10-year overall survival was 73.4 ± 12.6% and 89.3 ± 5.8% in patients treated with IST or HID-HSCT (P = .806). The failure-free survival was significantly inferior in patients receiving IST than in those undergoing transplantation from an HID (52.6 ± 10.5% vs 89.3 ± 5.8, P = .008). In univariate and multivariate analysis, the choice of first-line immunosuppressive therapy was the only adverse predictor for failure-free survival. At the last follow-up, completely normal blood count was observed in 11 of 20 (55.0%) and 24 of 25 (96.0%) live cases in IST and HID-HSCT cohort (P = .003). These suggest that HSCT from a haploidentical donor could be considered as first-line treatment in children who lack a matched related donor, especially in experienced transplantation centers.

Hematopoietic stem cell transplantation for acquired aplastic anemia

PURPOSE OF REVIEW

There has been a steady improvement in outcomes with allogeneic bone marrow transplantation (BMT) for severe aplastic anemia (SAA), because of progress in optimization of the conditioning regimens, donor hematopoietic cell source, and supportive care. Here, we review recently published data that highlight the improvements and current issues in the treatment of SAA.

RECENT FINDINGS

Approximately one-third of aplastic anemia patients treated with immune suppressive therapy (IST) have acquired mutations in myeloid cancer candidate genes. Because of the greater probability for eventual failure of IST, human leukocyte antigen (HLA)-matched sibling donor BMT is the first-line of treatment for SAA. HLA-matched unrelated donor (URD) BMT is generally recommended for patients who have failed IST. However, in younger patients for whom a 10/10-HLA-allele matched URD can be rapidly identified, there is a strong rationale to proceed with URD BMT as first-line therapy. HLA-haploidentical BMT using posttransplant cyclophosphamide conditioning regimens is now a reasonable second-line treatment for patients who failed IST.

SUMMARY

Improved outcomes have led to an increased first-line role of BMT for treatment of SAA. The optimal cell source from an HLA-matched donor is bone marrow. Additional studies are needed to determine the optimal conditioning regimen for HLA-haploidentical donors.

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.

Acquired aplastic anemia in Korean children: treatment guidelines from the Bone Marrow Failure Committee of the Korean Society of Pediatric Hematology Oncology

The treatment of choice for aplastic anemia (AA) in children has been HLA-matched family donor (MFD) hematopoietic stem cell transplantation (HSCT). For those lacking MFD, immunosuppressive therapy (IST) consisting of horse antithymocyte globulin (ATG) and cyclosporine has been successful. The choices of second and third line treatments are more complex and debatable, especially in the situation of unavailability of horse ATG. IST with rabbit ATG seems to be less effective. Recently, improved survival of non-MFD HSCTs has been documented. The outcome of matched or mismatched unrelated donor, umbilical cord blood, or haploidentical family donor transplantations will be discussed in AA children after IST failure. Experimental approaches of upfront HSCT using non-MFDs will be briefly touched. In this review, a treatment guideline for children with AA from the Korean Society of Pediatric Hematology Oncology will be presented along with a brief review of literature on current clinical practices in Korea.

Correlation of rabbit antithymocyte globulin serum levels and clinical outcomes in children who received hematopoietic stem cell transplantation from an alternative donor

We analyzed the correlation between rabbit ATG (rATG) serum levels and clinical outcomes in 37 children who received rATG at a total dose of 10 or 15 mg/kg during HSCT conditioning from an alternative donor. Fourteen patients had advanced malignant diseases, 13 had severe AA, and 10 had inherited disorders. Complete engraftment was achieved in all patients, and no rejection occurred. The cumulative incidence of grades II-IV acute GVHD and extensive chronic GVHD was 27% (95% CI, 12.5-39.6%) and 8.1% (95% CI, 0-23.1%), respectively. Multivariate analysis identified lower rATG levels at week 4 as an independent risk factor in the development of grades II-IV acute GVHD (p = 0.037). Serious infections were not observed in any patient following HSCT. No correlation was found between EBV reactivation and rATG levels at week 2 and week 4 after HSCT. Furthermore, no correlation was found between relapse and rATG levels two and four wk post-transplantation. The probability of five-yr OS among patients was 70.3% (95% CI, 59.8-79.2%). Our results suggest that targeted rATG administration may protect patients from severe acute GVHD without increasing the risk of EBV reactivation or relapse.

Evolving hematopoietic stem cell transplantation strategies in severe aplastic anemia

PURPOSE OF REVIEW

Significant improvements in unrelated donor hematopoietic stem cell transplantation (HSCT) in recent years have solidified its therapeutic role in severe aplastic anemia (SAA) and led to the evolution of treatment algorithms, particularly for children.

RECENT FINDINGS

Advances in understanding the genetics of inherited bone marrow failure syndromes (IBMFS) have allowed more confidence in accurately diagnosing SAA and avoiding treatments that could be dangerous and ineffective in individuals with IBMFS, which can be diagnosed in 10-20% of children presenting with a picture of SAA. Additionally long-term survival after matched sibling donor and matched unrelated donor HSCT now exceed 90% in children. Late effects after HSCT for SAA are minimal with current strategies, and compare favorably to late effects after upfront immunosuppressive therapy, except for patients with chronic graft versus host disease.

SUMMARY

Careful assessment for signs or symptoms of IBMFS, along with genetic screening for these disorders, is of major importance. Matched sibling donor HSCT is already considered the standard of care for upfront therapy and some groups are evaluating matched unrelated donor HSCT as primary therapy. Ongoing studies will continue to challenge treatment algorithms and may lead to an even more expanded role for HSCT in SAA.

Alemtuzumab based reduced intensity transplantation for pediatric severe aplastic anemia

BACKGROUND

Hematopoietic cell transplantation (HCT) is curative in patients with severe aplastic anemia (SAA). HCT is considered at presentation when a HLA-matched related donor (MRD) is available and has a high success rate. Unrelated donor (URD) transplants are typically undertaken if immunosuppressive therapy fails. Increased toxicity and graft rejection are often encountered in this setting.

PROCEDURE

We report a prospective multi-center trial of HCT in 17 children with SAA following novel reduced intensity conditioning with alemtuzumab, fludarabine and melphalan, and the best available donor. Nine were URD transplants matched at 7-8/8 loci, and performed following failure of immune suppression. Median follow up was 61 months (range 6-128).

RESULTS

All patients engrafted. Estimated 5 year event-free and overall-survival was 88% (95%CI 65.7-96.7). Five year overall survival for MRD and URD transplants was 100% and 78% (95%CI 45-93.6) respectively. Median times to neutrophil and platelet engraftment was 14 (range 10-27) and 23.5 (range 11-65) days respectively. Treatment related mortality was 12%. The incidence of grade II-IV and III-IV acute graft-versus-host disease was 29% and 18% respectively. At two years, all but one patient discontinued immunosuppression successfully. Laboratory measures of immune reconstitution normalized at one year and infection rates were low in the latter part of the first year.

CONCLUSIONS

HCT using this RIC approach was well tolerated and successful in achieving donor engraftment and early immune reconstitution with good quality of life free of immune suppression. Children with SAA can be successfully transplanted using alemtuzumab based conditioning.

Haploidentical hematopoietic stem cell transplantation in children and adolescents with acquired severe aplastic anemia

Severe aplastic anemia (SAA) is a life-threatening disorder for which allogeneic hematopoietic stem cell transplantation (HSCT) is the current available curative treatment. HSCT from matched sibling donors (MSDs) is the preferred therapy for children with acquired SAA. For patients who lack MSDs, immunosuppressive therapy (IST) is widely accepted as a first-line treatment before considering HCT from an unrelated donor (URD). Given the recent progress in HSCT using URDs for childhood SAA, well-matched URDs became a realistic alternative for pediatric patients who have no suitable related donors and who are refractory to IST. However, it is quite challenging to treat patients with refractory SAA who lack suitable related or URDs. Even though haploidentical HSCT from genetically mismatched family members seemed to be an attractive procedure with the amazing benefit of readily available donors for most patients, early attempts were disappointing because of refractory graft-versus-host disease (GVHD) and excessively high transplant-related mortality. Recent advances with effective ex vivo depletion of T cells or unmanipulated in vivo regulation of T cells, better supportive care, and optimal conditioning regimens have significantly improved the outcome of haploidentical transplant. Besides considerable progress in the treatment of malignant diseases, recent emerging evidences for haploidentical HSCT in SAA has provided additional therapeutic options for patients with refractory diseases. Further improvements to decrease the rates of graft failure, GVHD, and infectious complications will facilitate the emergence of haploidentical HSCT as a front-line therapy for treating acquired SAA in children and adolescents who have no suitably matched donors.

Matched related donor hematopoietic stem cell transplantation results in a long-term follow-up of a pediatric acquired severe aplastic anemia subset: A stem cell source perspective

HSCT has substantially improved pediatric acquired SAA patients' outcomes. Retrospectively, we attempted to assess the outcome of MRD HSCT in 65 pediatric patients referred to a single center from 1992 to 2012. We were particularly interested to find out whether source of SC (PB, n = 40 and BM, n = 25) significantly impacts EFS and GVHD incidence. With a median follow-up of 45 months, total EFS was 87.7%; EFS for PB and BM groups was 87.5% and 88%, respectively. Acute GVHD (grades 3-4) occurred in 13 patients (PB, n = 10 [25%] and BM, n = 3 [12%]), acute GVHD (grades 2-4) occurred in 24 (PB, n = 16 [40%] and BM, n = 8 [32%]). Extensive chronic GVHD occurred in five patients (PB, n = 3 [7.5%] and BM, n = 2 [8%]). Cox regression revealed that elapsed time of <10 months between diagnosis and HSCT is associated with improved survival (hazard ratio, 95% CI = 1.204, 1.010-1.434, p = 0.038). SC source did not significantly affect EFS, incidence of acute GVHD (grades 3-4), or extensive chronic GVHD (p = 0.938, 0.121, and 0.487, respectively). Based on our findings, pediatric acquired SAA patients are benefitted most if MRD-HSCT is carried out early in disease process and SC source does not affect outcome of MRD-HSCT in these patients.

Model-Based Determination of Effective Blood Concentrations of Cyclosporine for Neutrophil Response in the Treatment of Severe Aplastic Anemia in Children

Optimal immunosuppressive therapy in acquired severe aplastic anemia (SAA) remains to be refined, especially cyclosporine (CsA) use. Current recommendations state that CsA trough blood concentrations (TBC) should be maintained between 200 and 400 ng/mL despite the lack of supporting data. This study aimed at quantifying relationships between CsA exposure and neutrophil response and determining an effective range for CsA TBC. Twenty-three SAA patients treated with CsA were retrospectively analyzed. Nonlinear mixed effect modeling approaches were used to develop a pharmacokinetic-pharmacodynamic model. The pharmacokinetic model described the relationships between CsA doses and TBC. The pharmacodynamic model allowed to estimate boundaries for optimal CsA effects, neutrophils being used as biomarker of response. A time-to-event model linked effective concentration to time-to-therapeutic success. CsA TBC were adequately described by a two-compartment model with first-order absorption, a lag time, and a linear elimination. The efficient range of CsA TBC was estimated between 87 and 120 ng/mL. Model-based simulations and external validation in three additional patients confirmed these results. This original modeling approach was successful in describing the relationship between CsA TBC and neutrophil response in SAA patients. Although further evaluation of the model is necessary, this work suggests that an optimal CsA TBC target of 100 ng/mL would be associated with a better neutrophil response in children with SAA.

Advances in unrelated and alternative donor hematopoietic cell transplantation for nonmalignant disorders

PURPOSE OF REVIEW

The role of hematopoietic cell transplantation in non-malignant disorders has increased exponentially with the recognition that multiple diseases can be controlled or cured if engrafted with donor-derived cells. This review provides an overview of advances made in alternative donor transplants for nonmalignant disorders.

RECENT FINDINGS

Stem cell sources, novel transplant methods, and sophisticated supportive care have simultaneously made giant strides toward improving the safety and efficacy of hematopoietic cell transplantation. This has led to the utilization of marrow, cord, peripheral blood stem cell and haploidentical stem cell sources, and novel reduced toxicity or reduced intensity conditioning regimens to transplant non-malignant disorders such as immune dysfunctions, marrow failure syndromes, metabolic disorders and hemoglobinopathies. Transplant complications such as graft rejection, infections, and graft versus host disease are better combated in this modern era of medicine, achieving better survival with decreased late effects. These aspects of transplant for non-malignant disorders are discussed.

SUMMARY

This review presents the progress made in the realm of hematopoietic cell transplantation for non-malignant disorders. It advocates the consideration of alternative donor transplants in the absence of human leukocyte antigen matched siblings when indicated by disease severity. The ultimate goal is to provide curative transplant options for more patients that can benefit from this intervention, prior to detrimental outcomes.

First-line treatment for severe aplastic anemia in children: bone marrow transplantation from a matched family donor versus immunosuppressive therapy

The current treatment approach for severe aplastic anemia in children is based on studies performed in the 1980s, and updated evidence is required. We retrospectively compared the outcomes of children with acquired severe aplastic anemia who received immunosuppressive therapy within prospective trials conducted by the Japanese Childhood Aplastic Anemia Study Group or who underwent bone marrow transplantation from an HLA-matched family donor registered in the Japanese Society for Hematopoietic Cell Transplantation Registry. Between 1992 and 2009, 599 children (younger than 17 years) with severe aplastic anemia received a bone marrow transplant from an HLA-matched family donor (n=213) or immunosuppressive therapy (n=386) as first-line treatment. While the overall survival did not differ between patients treated with immunosuppressive therapy or bone marrow transplantation [88% (95% confidence interval: 86-90) versus 92% (90-94)], failure-free survival was significantly inferior in patients receiving immunosuppressive therapy than in those undergoing bone marrow transplantation [56% (54-59) versus 87% (85-90); P<0.0001]. There was no significant improvement in outcomes over the two time periods (1992-1999 versus 2000-2009). In multivariate analysis, age <10 years was identified as a favorable factor for overall survival (P=0.007), and choice of first-line immunosuppressive therapy was the only unfavorable factor for failure-free survival (P<0.0001). These support the current algorithm for treatment decisions, which recommends bone marrow transplantation when an HLA-matched family donor is available in pediatric severe aplastic anemia.

Pilot trial of risk-adapted cyclophosphamide intensity based conditioning and HLA matched sibling and unrelated cord blood stem cell transplantation in newly diagnosed pediatric and adolescent recipients with acquired severe aplastic anemia

BACKGROUND

Cyclophosphamide-based conditioning regimens and allogeneic hematopoietic stem cell transplantation (AlloHSCT) from matched related donors (MRD) has resulted in the highest survival rates in children and adolescents with acquired severe aplastic anemia (SAA). Time to transplant has consistently been associated with decreased overall survival. Reduced toxicity conditioning and AlloHSCT has been used successfully in other pediatric non-malignant diseases.

PROCEDURE

We piloted a risk-adapted AlloHSCT approach, using fludarabine and anti-thymocyte globulin based conditioning with high (200 mg/kg) and low (60 mg/kg) dose cyclophosphamide as upfront treatment in newly diagnosed pediatric patients with acquired SAA incorporating alternative donor sources, including cord blood. Average risk for non-engraftment patients with <10 transfusions received low dose cyclophosphamide (60 mg/kg); High Risk, those with ≥10 transfusions received conditioning regimen with higher intensity cyclophosphamide (200 mg/kg).

RESULTS

Seventeen patients were enrolled and underwent AlloHSCT including 12 males and 5 females with mean age of 8 years (range 3-16), and median follow-up time of 39 months (range 1-135). Donor sources included MRD BM (6/6 [n = 9], 5/6 [n = 2]) and unrelated CB (5/6 [n = 4], 4/6 [n = 2]). Five year OS was 67.6% (37.9-85.4). Three secondary graft failures (17.6%) occurred in the low dose cyclophosphamide arm.

CONCLUSIONS

Upfront treatment with risk-adapted cyclophosphamide conditioning AlloSCT is well tolerated for the management of newly diagnosed pediatric and adolescent patients with acquired SAA. However, the increased risk of graft rejection in the lower dose arm warrants additional research regarding the optimal intensity of cyclophosphamide-based conditioning regimen to reduce toxicity without increasing graft failure.

Peripheral blood lymphocyte telomere length as a predictor of response to immunosuppressive therapy in childhood aplastic anemia

Predicting the response to immunosuppressive therapy could provide useful information to help the clinician define treatment strategies for patients with aplastic anemia. In our current study, we evaluated the relationship between telomere length of lymphocytes at diagnosis and the response to immunosuppressive therapy in 64 children with aplastic anemia, using flow fluorescence in situ hybridization. Median age of patients was ten years (range 1.5-16.2 years). Severity of the disease was classified as very severe in 23, severe in 21, and moderate in 20 patients. All patients were enrolled in multicenter studies using antithymocyte globulin and cyclosporine. The response rate to immunosuppressive therapy at six months was 52% (33 of 64). The probability of 5-year failure-free survival and overall survival were 56% (95% confidence interval (CI): 41-69%) and 97% (95%CI: 87-99%), respectively. Median telomere length in responders was -0.4 standard deviation (SD) (-2.7 to +3.0 SD) and -1.5 SD (-4.0 to +1.6 (SD)) in non-responders (P<0.001). Multivariate analysis showed that telomere length shorter than -1.0 SD (hazard ratio (HR): 22.0; 95%CI: 4.19-115; P<0.001), platelet count at diagnosis less than 25×10(9)/L (HR: 13.9; 95%CI: 2.00-96.1; P=0.008), and interval from diagnosis to immunosuppressive therapy longer than 25 days (HR: 4.81; 95%CI: 1.15-20.1; P=0.031) were the significant variables for poor response to immunosuppressive therapy. Conversely to what has been found in adult patients, measurement of the telomere length of lymphocytes at diagnosis is a promising assay in predicting the response to immunosuppressive therapy in children with aplastic anemia.

Increased immunosuppressive treatment combined with unrelated umbilical cord blood infusion in children with severe aplastic anemia

A combination treatment of unrelated umbilical cord blood (UCB) and increased immunosuppressive treatment (IST) were investigated to reveal the potentially curative therapy for the severe aplastic anemia (SAA). A total of 36 children (2-17 ages) with SAA who received UCB infusion after an IST were analyzed. The treatment consisted of 100mg/kg cyclophosphamide, 12.5-15 mg/kg antithymocyte globulin and 3mg/kg cyclosporine. After 3 months, the hematologic complete response (CR) rate was 22.2% and partial response (PR) rate was 38.9%. After 6 months, the CR rate and PR rate was 50.4% and 26.3%, respectively. The probability of 3-year survival was 83.3%. There was no difference in the survival rate either between the horse-ATG and rabbit-ATG or between the SAA and VSAA. The results indicated that the increased IST combined with unrelated UCB infusion has an effective therapeutic potential for children with SAA who lack of compatible donor for transplantation.

Outcome of pediatric acquired aplastic anemia: a developing world experience

INTRODUCTION

Outcome data of children with acquired aplastic anemia (AA) are lacking from the developing world. Here, we describe the same from a centre in North India.

METHODS

Retrospective data regarding medical history, physical examination, complete blood count, bone marrow aspirate, and biopsy were retrieved for all children <18 years, with acquired AA admitted between January 2005 and June 2012. In addition, the outcome data after immunosuppressive therapy (IST) or bone marrow transplant (BMT) was obtained.

RESULTS

A total of 61 children were diagnosed with AA (Inherited-18 and acquired-43). Among 43 children with acquired AA, 3 had nonsevere and 40 had severe. One patient with nonsevere AA died of sepsis and 2 recovered spontaneously. Of the 40 remaining children with severe AA, 10 refused therapy and 3 died due to severe sepsis prior to any therapy. Five underwent upfront matched sibling donor BMT and one post-IST failure. Four year overall survival (OS) and event free survival (EFS) for children undergoing BMT was 100% and 80 ± 17.9, respectively. Out of 22 treated with IST, 20 were evaluable for response. Seventeen received one course and 3 received two course of IST. The overall response to IST was seen in 14/20 (70%). Only two achieved complete response while remaining 12 had partial response. The 4-year estimated OS and EFS for children treated with IST was 74.4 ± 12.1% and 65.6 ± 12.2.

CONCLUSION

Outcomes for children with AA are encouraging in the developing world although barriers like sepsis and treatment abandonment remain. BMT offers faster and complete recovery.

Hematopoietic stem cell transplantation in children and young adults with secondary myelodysplastic syndrome and acute myelogenous leukemia after aplastic anemia

Secondary myelodysplastic syndrome and acute myelogenous leukemia (sMDS/sAML) are the most serious secondary events occurring after immunosuppressive therapy in patients with aplastic anemia. Here we evaluate the outcome of hematopoietic stem cell transplantation (HSCT) in 17 children and young adults with sMDS/sAML after childhood aplastic anemia. The median interval between the diagnosis of aplastic anemia and the development of sMDS/sAML was 2.9 years (range, 1.2 to 13.0 years). At a median age of 13.1 years (range, 4.4 to 26.7 years), patients underwent HSCT with bone marrow (n = 6) or peripheral blood stem cell (n = 11) grafts from HLA-matched sibling donors (n = 2), mismatched family donors (n = 2), or unrelated donors (n = 13). Monosomy 7 was detected in 13 patients. The preparative regimen consisted of busulfan, cyclophosphamide, and melphalan in 11 patients and other agents in 6 patients. All patients achieved neutrophil engraftment. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 47%, and that of chronic GVHD was 70%. Relapse occurred in 1 patient. The major cause of death was transplant-related complication (n = 9). Overall survival and event-free survival at 5 years after HSCT were both 41%. In summary, this study indicates that HSCT is a curative therapy for some patients with sMDS/sAML after aplastic anemia. Future efforts should focus on reducing transplantation-related mortality.

Allogeneic stem cell transplantation for children with acquired severe aplastic anaemia: a retrospective study by the Viva-Asia Blood and Marrow Transplantation Group

We retrospectively analysed the outcomes of 127 children with acquired severe aplastic anaemia (SAA) who had received haematopoietic stem cell transplantation (HSCT) between 2000 and 2011 in one of the 10 Asia Pacific institutions. Fifty-three were matched sibling donor (MSD) and 74 were alternative donor (AD), including 22 matched unrelated donor, 32 mismatched unrelated donor and 20 mismatched related donor. With a median follow up 45.5 months (13-139) and when compared to the MSD group, AD recipients had more grade II-IV acute graft-versus-host disease (aGVHD; 14.3% vs. 32.8%, P = 0.029), but similar grade III-IV aGVHD (10.2% vs. 12.5%, P = 0.774), graft failure (GF) (15.1% vs. 15.5%, P = 0.658) and 5-year overall survival (90.6% vs. 83.7%, P = 0.251). As a source of stem cell, peripheral blood stem cells (PBSC) resulted in less GF (18% vs. 9.1% P = 0.013), similar grade II-IV aGVHD (28.1% vs. 17.4%, P = 0.258), chronic GVHD (25.8% vs. 29.3%, P = 0.822) and similar outcomes (89.7% vs. 82.4%, P =0.665) when compared to bone marrow (BM). In univariate analysis, GF (P < 0.001) and grade II-IV aGVHD (P = 0.009) were predictors of poor survival. In multivariate analysis, only GF was associated with poor survival (P = 0.012). The outcome of AD and PBSC HSCT were comparable to that of MSD and BM HSCT in the Asia Pacific region.

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.

Management of acquired aplastic anemia in children

The diagnosis of aplastic anemia in children requires exclusion of a variety of inherited or acquired BM failure syndromes with similar phenotypes. An efficient diagnostic plan is important because time from diagnosis to 'final' treatment is directly related to outcome regardless of the therapeutic option chosen. The gold standard of therapy remains hematopoietic SCT with a graft of BM cells for those children with matched sibling donors. Conversely for children without a sibling donor the high response and markedly improved overall survival rates of combined immunosuppressive therapy have proven robust, especially when horse derived anti-thymocyte globuline plus ciclosporine A are used. Incomplete response, relapse and progression to myelodysplasia/leukemia however have emerged as significant long-term issues. Improvements in outcome of alternative donor transplantation and the use of established and novel immunosuppressive agents provide multiple alternatives for treating refractory or relapsed patients. Regardless of the type of therapeutic approach, patients require centralized treatment in a center of excellence, ongoing monitoring for recurrence of disease and/or therapy-related immediate side effects and long-term effects.

How I manage aplastic anaemia in children

Aplastic anaemia (AA) is a rare heterogeneous condition in children. 15-20% of cases are constitutional and correct diagnosis of these inherited causes of AA is important for appropriate management. For idiopathic severe aplastic anaemia, a matched sibling donor (MSD) haematopoietic stem cell transplant (HSCT) is the treatment of choice. If a MSD is not available, the options include immunosuppressive therapy (IST) or unrelated donor HSCT. IST with horse anti-thymocyte globulin (ATG) is superior to rabbit ATG and has good long-term results. In contrast, IST with rabbit ATG has an overall response of only 30-40%. Due to improvements in outcome over the last two decades in matched unrelated donor (MUD) HSCT, results are now similar to that of MSD HSCT. The decision to proceed with IST with ATG or MUD HSCT will depend on the likelihood of finding a MUD and the differing risks and benefits that each therapy provides.

First-line matched related donor hematopoietic stem cell transplantation compared to immunosuppressive therapy in acquired severe aplastic anemia

Introduction

Acquired severe aplastic anemia (SAA) is a rare and progressive disease characterized by an immune-mediated functional impairment of hematopoietic stem cells. Transplantation of these cells is a first-line treatment option if HLA-matched related donors are available. First-line immunosuppressive therapy may be offered as alternative. The aim was to compare the outcome of these patients in controlled trials.

Methods

A systematic search was performed in the bibliographic databases MEDLINE, EMBASE, and The Cochrane Library. To show an overview of various outcomes by treatment group we conducted a meta-analysis on overall survival. We evaluated whether studies reported statistically significant factors for improved survival.

Results

26 non-randomized controlled trials (7,955 patients enrolled from 1970 to 2001) were identified. We did not identify any RCTs. Risk of bias was high except in 4 studies. Young age and recent year of treatment were identified as factors for improved survival in the HSCT group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the IST group. In 19 studies (4,855 patients), summary statistics were sufficient to be included in meta-analysis. Considerable heterogeneity did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies.

Conclusions

Young age and recent year of treatment were identified as factors for improved survival in the transplant group. Advanced age, SAA without very severe aplastic anemia, and combination of anti-lymphocyte globulin with cyclosporine A were factors for improved survival in the immunosuppressive group. Considerable heterogeneity of non-randomized controlled studies did not justify a pooled estimate. Adverse events were inconsistently reported and varied significantly across studies.

Predicting response to immunosuppressive therapy in childhood aplastic anemia

In aplastic anemia, predictive markers of response to immunosuppressive therapy have not been well defined. We retrospectively evaluated whether clinical and laboratory findings before treatment could predict response in a pediatric cohort from the multicenter AA-97 study in Japan. Between 1997 and 2006, 312 newly diagnosed children were enrolled and treated with a combination of antithymocyte globulin and cyclosporine. In multivariate analyses, lower white blood cell count was the most significant predictive marker of better response; patients with white blood cell count less than 2.0×10(9)/L showed a higher response rate than those with white blood cell count of 2.0×10(9)/L or more (P=0.0003), followed by shorter interval between diagnosis and therapy (P=0.01), and male sex (P=0.03). In conclusion, pre-treatment clinical and laboratory findings influence response to therapy. The finding that response rate worsens with increasing interval between diagnosis and treatment highlights the importance of prompt immunosuppressive therapy for patients with aplastic anemia.

Successful bone marrow transplantation for children with aplastic anemia based on a best-available evidence strategy

  A best-available evidence strategy, i.e., the best-available donors, conditioning regimens and GVHD prophylaxis were chosen at the time of BMT for AA, was analyzed retrospectively. The outcomes for 18 children with AA who underwent allogeneic BMT were analyzed. The median age was 11 yr (range 4-16), and nine were men. As conditioning regimens, seven had low-dose irradiation + CY, six had ATG + CY + Flu, and five had ATG + CY. Donors were HLA-matched siblings in 10, HLA-mismatched family in one, HLA-matched unrelated in three, and HLA-mismatched unrelated in four. As GVHD prophylaxis, three received CsA alone, nine received CsA + MTX, and six received tacrolimus + MTX. All 18 patients showed engraftment. The median number of days until the neutrophil count exceeded 500/μL was 16 (range 11-21) post-transplant. Five developed more than grade 2 acute GVHD, and three developed extensive cGVHD. One patient died because of interstitial pneumonia complicated with cGVHD. Five-yr OS was 94% (95% CI: 83-105). These results suggest that a strategy of treating patients based on the best-available evidence is acceptable.

Outcomes of matched sibling and alternative donor stem cell transplantation for 26 children with severe aplastic anemia

In this study, we reported the outcomes of hematopoietic stem cell transplantation (HSCT) as a treatment modality for pediatric patients admitted over the past 20 years in a single institute. From January 1989 to January 2007, 26 patients with a median age of 8 years underwent 14 matched sibling donor (MSD) and 12 alternative donor (AD) transplantations. Two patients received second transplantation successfully after primary graft failure and late graft rejection. Two patients who received transplantation from matched unrelated donors (MUD) died of sepsis, and one of them also had a graft failure at death. The overall 5-year survival rate was 92.1%: 83.3% for AD transplantation and 100% for MSD transplantation. Grade II acute graft versus host disease (GVHD) developed in 3 patients, and extensive chronic GVHD developed in 2 patients. An interval of more than 6 months from diagnosis to transplantation was the major poor prognostic factor for our patients' survival. Thus, in our experience, HSCT from a MSD remains the first choice of treatment for pediatric patients with severe aplastic anemia. For patients without MSD, transplantation from an AD can also result in long-term survival. Earlier transplantation after diagnosis can also result in better outcomes.

Allogeneic hematopoietic stem cell transplantation is superior to immunosuppressive therapy in Indian children with aplastic anemia--a single-center analysis of 100 patients

The authors compared the outcome in 100 children (61 boys, 39 girls; median age of 10.1 +/- 3.4 years) with aplastic anemia who underwent either immunosuppressive therapy (IST; n = 70) or hematopoietic stem cell transplantation (HSCT; n = 30) between 1998 and 2007. Conditioning regimes for HSCT were a combination of either cyclophosphamide (Cy) with antilymphocyte globulin (ALG) or fludarabine (Flu) with Cy or busulfan (Bu) +/- antithymocyte globulin (ATG). Stem cell source was bone marrow in 20 and peripheral blood stem cells (PBSCs) in 10. Patients undergoing IST received either equine ALG or ATG in combination with steroids and cyclosporine. Primary engraftment was seen in 25 children (83.3%), with acute graft-versus-host disease (aGvHD) in 5 (16.6%). The day 100 transplant-related mortality (TRM) was 30% and at a median follow up of 36 months (range: 6-197), the overall and disease-free survival is 70%. Among children who received IST, 60 children received ALG while 10 received ATGAM. Responses were seen in 27 children (43.5%), which was complete (CR) in 12 and partial (PR) in 15. At a median follow up of 38 months (range: 1-84), the overall survival is 37.1%, with 81.4% survival among responders and <10% survival among non-responders. HSCT would be the treatment of choice in children with severe aplastic anemia who have a human leukocyte antigen (HLA)-matched related donor and is superior to IST in this series from India.

High-dose cyclophosphamide for severe aplastic anemia: long-term follow-up

Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disorder that can be treated with bone marrow transplantation, immunosuppressive therapy, and high-dose cyclophosphamide. Here, we report long-term follow-up on 67 SAA patients (44 treatment-naive and 23 refractory) treated with high-dose cyclophosphamide. At 10 years, the overall actuarial survival was 88%, the response rate was 71% with the majority being complete, and the actuarial event-free survival was 58% in 44 treatment-naive SAA patients. Patients with refractory SAA fared less well after high-dose cyclophosphamide therapy; at 10 years, overall actuarial survival, response, and actuarial event-free survival rates were 62%, 48%, and 27%, respectively. High-dose cyclophosphamide is highly effective therapy for severe aplastic anemia. Large randomized controlled trials will be necessary to establish how results of high-dose cyclophosphamide compare with either bone marrow transplantation or standard immunosuppressive regimens, such as antithymocyte globulin and cyclosporine.

Tacrolimus/Methotrexate versus cyclosporine/methotrexate as graft-versus-host disease prophylaxis in patients with severe aplastic anemia who received bone marrow transplantation from unrelated donors: results of matched pair analysis

Tacrolimus (FK) and cyclosporine (CsA) have been shown to be effective in the prophylaxis of graft-versus-host disease (GVHD). However, no comparative studies have yet been conducted to examine the efficacy of FK/methotrexate (MTX) and CsA/MTX in patients with severe aplastic anemia (SAA) given unrelated donor bone marrow transplantation (U-BMT). We used matched-pair analysis to compare FK/MTX with CsA/MTX in patients with SAA who received U-BMT through the Japan Marrow Donor Program. Forty-seven pairs could be matched exactly for recipient age and conditioning regimens. Forty-five patients achieved engraftment in the FK group and 42 patients in the CsA group. The probability of grade II-IV acute GVHD (aGVHD) was 28.9% in the FK group and 32.6% in the CsA group (P=.558). The probability of chronic GVHD (cGVHD) was 13.3% in the FK group and 36.0% in the CsA group (P=.104). The 5-year survival rate was 82.8% in the FK group and 49.5% in the CsA group (P=.012). The study shows the superiority of FK/MTX over CsA/MTX in overall survival because of the lower incidence of transplantation-related deaths. A prospective randomized study comparing FK/MTX and CsA/MTX is warranted.

Single-Center Experience: immunosuppressive therapy as frontline treatment for 33 children with acquired severe aplastic anemia

The authors retrospectively analyzed the records of 33 children with acquired severe aplastic anemia (SAA) diagnosed from July 1998 to October 2007 and first treated by immunosuppressive therapy (IST). Serial hematologic parameters, complications, transfusion requirements, and time to response were assessed. Allogeneic hematopoietic stem cell transplantation (HSCT) was attempted in 7 patients after failure of IST (n = 6) or relapse following an initial response to IST (n = 1). One child died of post-transplant lymphoproliferative disorder. Thirty of the 33 patients are alive and well after a median follow-up of 45 months (range, 7-116 months). Overall (transfusion-independent) response to IST was 73% (24/33). The actuarial 5 years survival rate was 89.4%. In this study, all patients with SAA received IST as standard front-line therapy. Approximately three-fourths of patients with SAA have durable recovery and excellent overall survival.

Aplastic anaemia in childhood. Description of two cases and review of the literature

Childhood aplastic anaemia (AA) is an uncommon but potentially fatal haematological disorder. Patients with AA receive supportive care based on transfusions and timely treatment of opportunistic infections, along with specific therapies, which may be bone marrow transplantation and immunosuppressive therapy. Early diagnosis and supportive therapy are required to prevent fatal complications like overwhelming sepsis or life threatening haemorrhages. We report two cases of aplastic anaemia having a different aetiology. The diagnostic work-up and the therapeutic management for each case are described below.

Allogeneic haemopoietic stem cell transplantation in children: what alternative donor should we choose when no matched sibling is available?

Allogeneic haemopoietic stem cell transplantation has provided curative therapy for life-threatening malignant and non-malignant diseases in children for over 40 years. Only 25% of children in whom an allograft is indicated have the ideal option of a human leucocyte antigen-identical sibling donor. Substantial advances in the use of alternative donors (unrelated volunteer donors, haploidentical family donors and unrelated umbilical cord blood donors) now make it possible for almost all children to benefit from this life-saving treatment. Each donor choice is associated with distinct advantages and disadvantages, which have greater or lesser importance in different diseases. We review the current status of alternative donor transplantation for haematological malignancies, primary immunodeficiencies, inherited metabolic disorders and bone marrow failure syndromes and outline the current UK consensus donor selection algorithms for these disease groups.

Hematopoietic stem cell transplantation for bone marrow failure syndromes in children

Bone marrow failure (BMF) syndromes include a broad group of diseases of varying etiologies, in which hematopoeisis is abnormal or completely arrested in one or more cell lines. BMF can be an acquired aplastic anemia (AA) or can be congenital, as part of such syndromes as Fanconi anemia (FA), Diamond Blackfan anemia, and Schwachman Diamond syndrome (SDS). In this review, we first address the evolution and current status of bone marrow transplantation (BMT) in the pediatric population in the most common form of BMF, acquired AA. We then discuss pediatric BMT in some of the more common inherited BMF syndromes, with emphasis on FA, in which experience is greatest. It is important to consider the possibility of a congenital etiology in every child (and adult) with marrow failure, because identification of an associated syndrome provides insight into the likely natural history of the disease, as well as prognosis, treatment options for the patient and family, and long-term sequelae both of the disease itself and its treatment.

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.

Private cord blood banking: experiences and views of pediatric hematopoietic cell transplantation physicians

OBJECTIVE

Private cord blood banks are for-profit companies that facilitate storage of umbilical cord blood for personal or family use. Pediatric hematopoietic cell transplantation physicians are currently best situated to use cord blood therapeutically. We sought to describe the experiences and views of these physicians regarding private cord blood banking.

PARTICIPANTS AND METHODS

We e-mailed a cross-sectional survey to pediatric hematopoietic cell transplantation physicians in the United States and Canada; 93 of 152 potentially eligible physicians (93 of 130 confirmed survey recipients) from 57 centers responded. Questions addressed the number of transplants performed by using privately banked cord blood, willingness to use banked autologous cord blood in specific clinical settings, and recommendations to parents regarding private cord blood banking.

RESULTS

Respondents reported having performed 9 autologous and 41 allogeneic transplants using privately banked cord blood. In 36 of 40 allogeneic cases for which data were available, the cord blood had been collected because of a known indication in the recipient. Few respondents would choose autologous cord blood over alternative stem cell sources for treatment of acute lymphoblastic leukemia in second remission. In contrast, 55% would choose autologous cord blood to treat high-risk neuroblastoma, or to treat severe aplastic anemia in the absence of an available sibling donor. No respondent would recommend private cord blood banking for a newborn with 1 healthy sibling when both parents were of northern European descent; 11% would recommend banking when parents were of different minority ethnicities.

CONCLUSIONS

Few transplants have been performed by using cord blood stored in the absence of a known indication in the recipient. Willingness to use banked autologous cord blood varies depending on disease and availability of alternative stem cell sources. Few pediatric hematopoietic cell transplantation physicians endorse private cord blood banking in the absence of an identified recipient, even for mixed-ethnicity children for whom finding a suitably matched unrelated donor may be difficult.

[Severe acquired aplastic anemia: historical outcome of patients treated by allogeneic bone marrow transplantation from matched sibling donors. A study by the Spanish Group for Bone Marrow Transplantation in Children (GETMON)]

INTRODUCTION

Allogeneic haematopoietic stem-cell transplantation is the treatment of choice for acquired aplastic anaemia in children. Experience with this approach from Spanish Working Party for Bone Marrow Transplantation in Children in two sequential time periods (1982-1990 and 1991-2004) is reported.

PATIENTS AND METHODS

Sixty two consecutive patients with a median age of 10 years were transplanted; 18 in the 1982-1990 period and 44 in the 1991-2004 period. Conditioning regimen consisted mainly of irradiation and cyclophosphamide in the first period (72 % of patients) and cyclophosphamide +/- anti-thymocyte globulin (62 %) in the second. Graft versus host disease prophylaxis consisted of cyclosporine in most patients (57/62).

RESULTS

Fifty one patients are alive and disease-free at a median follow-up of 127 months. Five years probability of event-free survival is 82 %. The survival increased from 61 % to 91 % during the two time periods. Eleven patients died from graft failure or rejection (3), acute or chronic graft versus host disease and infection (4) or multi-organ failure (4). Univariate analysis identified two significant prognostic factors: interval diagnostic/transplant and time period of transplant (for both p = 0.03).

CONCLUSIONS

This experience corroborates that allogeneic haematopoietic stem-cell transplantation is the best treatment for severe acquired aplastic anaemia, with a current disease-free survival of 90 % of patients.

[Evaluation of a prospective therapeutic protocol in adult patients with nonsevere aplastic anemia in South Tunisia]

INTRODUCTION

Immunosuppressive drugs are usually used in the treatment of acquired aplastic anemia (AAA). The aim of this study was to evaluate the efficiency of a prospective therapeutic protocol using cyclosporine and androgens in the treatment of adult patients with nonsevere AAA.

METHODS

Twenty-nine patients diagnosed and treated at the University Hospital of Sfax (Tunisia), during a 10-year period (1991-2000) were included. In addition to symptomatic treatment (transfusion, antibiotics), all the patients received a specific treatment including two drugs: cyclosporine 5mg/kg per day and androgens 0,5mg/kg per day.

RESULTS

The response rate at three, six and 12 months were 48, 75, and 87%, respectively. Survival rate was 52% at one year, and 37% at five and 10 years. The main toxicities were hepatic, renal, and hypertension, observed in 53, 16 and 15%, respectively. These toxicities were reversible in 65, 87 and 100% of the cases, respectively.

CONCLUSION

The response and survival rates in our series are quite satisfactory when compared to those obtained with other immunosuppressive drugs (cyclosporine and antilymphocyte serum) in the literature. The addition of androgens in our patients seemed to potentiate the immunosuppression induced by ciclosporin, but secondary toxic effects were more common.