Improved prognosis for acquired aplastic anaemia

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.

Should we still use Camitta's criteria for severe aplastic anemia?

Background

The criteria by Camitta for diagnosis in severe aplastic anemia (SAA) has been used since 1976. However, there has been no attempt to verify the Camitta's criteria, that the survival in patients with SAA may differ by absolute neutrophil count (ANC), platelet count (PLT), and corrected reticulocyte count (CRC), which are components of the Camitta's criteria.

Methods

117 SAA patients diagnosed by the Camitta's criteria were analyzed, retrospectively. Univariate and multivariate analyses were used to evaluate the factors affecting overall survival (OS).

Results

Response by immunosuppressive therapy (IST) or stem cell transplantation (SCT) significantly affected OS (P=0.001). Therefore, we excluded treatment responders for analysis. Finally, 92 SAA patients including treatment non-responders by IST or SCT and conservative care group were analyzed by using univariate and multivariate analyses. The median age of analyzed patients was 54.5 years. Male to female ratio was 1:1. The median follow-up duration was 74.23 months (range, 54.71-93.74 months). The median ANC, PLT, and CRC were 394/µL, 12,000/µL, and 0.39%, respectively. In multivariate analyses, ANC <500/µL or ≥500/µL (P=0.015, HR 2.694, 95% CI: 1.20-6.01) and age (P=0.015, HR 1.022, 95% CI: 1.00-1.04) were the significant factors for OS.

Conclusion

ANC could be an essential, not an optional criterion for diagnosing SAA. This study suggests the possibility that the Camitta's criteria be modified. Studies in large cohorts are needed to transform the Camitta's criteria.

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.

Radionuclide imaging of bone marrow disorders

Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as ^99mTc-nanocolloid, ^99mTc-sulphur colloid, ¹¹¹In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using ¹⁸F-FDG and ¹⁸F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed.

Favorable outcome with allogeneic hematopoietic stem cell transplantation in pediatric acquired aplastic anemia patients

The data of allogeneic HSCT in nine children with acquired AA between June 1998 and July 2006 were analyzed retrospectively. The median duration of time to neutrophil and platelet engraftment was 18 and 25 days, respectively. None of the patients had primary graft failure. Two (22.2%) patients developed acute GVHD and of these, one (11.1%) was Grade 1, and the other (11.1%) was Grade 3. Although the study group was composed of higher risk patients, including six of nine resistant to previous immunosuppressive treatment, eight had multiple not irradiated or filtered transfusion histories and one of the cases was only 5/6 HLA-compatible with his donor, the five-yr overall and EFS was 100%, and all recipients are alive without any graft failure. This may be attributed to the dose adjusted use of ATG according to individual transfusion history and gradual tapering of CsA and cessation at least nine months after allogeneic HSCT.

Diagnosis and treatment of children with aplastic anemia

BACKGROUND

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

METHODS

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

CONCLUSIONS

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

Successful recovery of aplastic anemia following orthotopic liver transplantation for non-A-E acute liver failure

This report describes a teenager who developed aplastic anemia (AA) because of non-A-E acute liver failure (ALF) requiring orthotopic liver transplantation (OLT). His AA did not recover spontaneously and he required treatment with ATG 9 months post-OLT. Bone marrow recovery occurred 4 months after immunotherapy and coincided with further intensification of immunusuppression required to treat early chronic rejection of the liver graft. Three years post-OLT he remains well with good bone marrow and liver function. Intensification of immunosuppression can lead to successful resolution of AA associated with non-A-E ALF.

Improved outcome of alternative donor bone marrow transplantation in children with severe aplastic anaemia using a conditioning regimen containing low-dose total body irradiation, cyclophosphamide and Campath

The increasing success of human leucocyte antigen (HLA)-matched sibling donor (MSD) transplants and combination immunosuppressive treatments have dramatically improved the prognosis of severe aplastic anaemia (SAA) in children and young adults. For patients who lack a MSD there is a significant minority who fail immunosuppressive therapy or suffer from a severe constitutional aplastic anaemia in which immunosuppression would be ineffective. Alternative donor bone marrow transplantation (AD-BMT) has only had limited success in this context. We report the successful outcome of AD-BMT in eight consecutive patients aged 7 months to 15 years, six of whom had acquired aplastic anaemia who had previously failed to respond to immunosuppression, and two of whom had a severe (non-Fanconi) constitutional aplastic anaemia. All eight patients had received multiple red cell and platelet transfusions. We used a new combination of agents for pretransplant conditioning aiming to maximize immunosuppression and minimize toxicity, consisting of Campath-1G or -1H, cyclophosphamide and low-dose total body irradiation (LD TBI) or fludarabine. Toxicity was minimal and all eight children are alive, well and free of disease at a median follow-up of 32 months. We suggest that this approach could facilitate the successful treatment of children with SAA in whom immunosuppressive therapy has failed or is not appropriate.

Bone marrow failure in children with acute liver failure

BACKGROUND

Aplastic anemia is a rare but well-recognized complication of acute hepatitis and acute liver failure. The cause is unknown, and the condition is fatal without bone marrow recovery. Treatment includes immunosuppression regimens or bone marrow transplantation. The purpose of this study was to investigate the incidence, cause, treatment, and outcomes of this disorder in children.

METHODS

Retrospective chart review of 75 patients with acute liver failure in a major pediatric liver center.

RESULTS

Eight patients had evidence of bone marrow failure. Of those, six had aplastic anemia, and two had transient bone marrow suppression. There were five boys, median age 57 months (range, 36-132 months). Two had parvovirus B19, six had non-A, non-B, non-C hepatitis. Five underwent liver transplantation: auxiliary in one, orthotopic in four. The interval between initial symptoms and development of aplastic anemia and/or bone marrow suppression was 21 to 99 days (median, 39 days). Four patients with aplastic anemia received intravenous antithymocyte globulin (ATG) or antilymphocyte globulin (ALG). Median recovery period of granulopoiesis was 62 days (range, 27-115 days). Two made a full recovery, one had myelodysplasia, and one with unresponsive disease died of septic complications. Four did not receive ATG/ALG, two had aplastic anemia, and two had bone marrow suppression. Three underwent liver transplantation, and all four resumed granulopoiesis. One child who underwent liver transplantation died of sepsis with chronic rejection. Median recovery of granulopoiesis was 99 days (range, 20-153 days).

CONCLUSIONS

Bone marrow failure occurs in 10.7% of children with acute liver failure. It sometimes occurs in association with non-A, non-B, non-C hepatitis and parvovirus B19 infection. Treatment with ATG/ALG is successful and is well tolerated in most cases.

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

A total of 100 children under the age of 17 years with acquired aplastic anaemia (AA) were initially treated with immunosuppressive therapy (IST) (n = 63) or bone marrow transplantation (BMT) (n = 37) from an HLA-matched family donor. The projected 10-year survival rates were 55 +/- 8% and 97 +/- 3% respectively (P = 0.004). Because the IST group included 11 non-responders who were salvaged by BMT from an HLA-matched unrelated donor, we compared failure-free survival (FFS) between the groups. The probability of FFS at 10 years was 97 +/- 3% for the BMT group, compared with 40 +/- 8% for the IST group (P = 0.0001). Seven patients evolved to myelodysplastic syndrome (MDS) with monosomy 7 and the estimated cumulative incidence of MDS 10 years after diagnosis was 20 +/- 7% in the IST group. We compared the outcome of children treated with IST during the two consecutive periods of 1983-91 (group A, n = 40) and 1991-8 (group B, n = 23) to assess the impact of combined therapy with antithymocyte globulin and cyclosporin. The probability of FFS at 7 years follow-up was the same in the two groups (50 +/- 8% vs. 40 +/- 15%, P = 0.40). We recommend BMT as first-line therapy in paediatric severe AA patients with an HLA-matched family donor. Alternative donor BMT is recommended as salvage therapy in patients who relapse or do not respond to initial IST.

Stem cell transplantation for non-malignant disorders

Stem cell transplantation (SCT) can be used to cure or ameliorate a wide variety of non-malignant diseases. These range from inherent defects of haemopoietic cell production or function, through metabolic diseases (where blood cells are providing in vivo enzyme therapy to solid organs), to severe autoimmune diseases. However, although transplantation has revolutionized the treatment of many of the diseases discussed, severe toxicities remain. In some cases these are inherent to the disease concerned but frequently they relate to the conditioning regime or post-transplant complications such as graft-versus-host disease (GvHD). This chapter concentrates on the indications for transplant, outcome statistics and problems inherent in particular conditions, seen in the light of technological improvements during the 1990s and the potential impact of enzyme and gene therapies.