Allogeneic stem cell transplantation for aplastic anemia

Incidence and risk factors for secondary graft failure in uniformly treated patients with severe aplastic anemia receiving fludarabine and cyclophosphamide for conditioning and matched sibling bone marrow graft as stem cell source

BACKGROUND AIMS

Graft failure after allogeneic transplant for aplastic anemia is problematic. The risk of graft failure depends on multiple variables, including the preparative regimen, donor type, stem cell dose and source among other variables.

METHODS

We performed a retrospective analysis of patients with aplastic anemia who underwent matched-sibling allogeneic transplant at a single center.

RESULTS

We identified 82 patients who fit the inclusion criteria. One had primary graft failure and was excluded from this analysis. The recipient median age was 22 years. The donor median age was 23 years. The median time from diagnosis to transplant was 1.6 months. The median number of red cell transfusions before transplant was nine. The median number of platelet transfusions before transplant was 18. Thirteen patients developed secondary graft failure, with a cumulative incidence at 5 years of 16% and median time to develop secondary graft failure of 129 days. All patients engrafted with a median time for neutrophil engraftment of 19 days and a median time for platelet engraftment of 22 days. The survival of patients with or without secondary graft failure was not different. Major or bidirectional ABO incompatibility and older recipient age were statistically significantly associated with greater risk of secondary graft failure.

CONCLUSIONS

Secondary graft failure is a significant complication after allogeneic transplant for SAA. Identification of recipients at risk and mitigating the potential risks of this complication is warranted.

Association between haploidentical hematopoietic stem cell transplantation combined with an umbilical cord blood unit and graft-versus-host disease in pediatric patients with acquired severe aplastic anemia

Background:

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) based on granulocyte colony-stimulating factor plus anti-thymocyte regimens (‘Beijing Protocol’) provides a salvage treatment for patients of acquired severe aplastic anemia (SAA) in China. However, graft-versus-host disease (GVHD) is a major impediment of haplo-HSCT due to human leukocyte antigen disparity. Recently, haplo-HSCT combined with umbilical cord blood (UCB) (haplo-cord HSCT) is performed in clinical trials to potentially reduce the risk of severe GVHD. Nevertheless, studies comparing GVHD in pediatric patients receiving haplo and haplo-cord HSCT for SAA are limited.

Objective:

The objective of this study was to investigate the impact of UCB co-infusion on GVHD in pediatric patients receiving haplo-HSCT for SAA.

Design:

We conducted a retrospective study of 91 consecutive SAA children undergoing haploidentical transplantation based on the ‘Beijing Protocol’ with or without co-infusion of UCB in our center.

Methods:

All patients received uniform non-myeloablative conditioning and GVHD prophylaxis. We compared baseline characteristics and transplant outcomes between the haplo (n = 35) and haplo-cord (n = 56) recipients.

Results:

All 91 patients achieved hematopoietic recovery from haploidentical donors, with a higher incidence of peri-engraftment syndrome observed with the haplo-cord group as compared with the haplo group (75.0% versus 48.6%, p = 0.029). Notably, the haplo-cord group showed a lower incidence of II–IV acute GVHD (aGVHD) than the haplo group (16.1% versus 42.9%, p = 0.002). Observed incidences of chronic GVHD (cGVHD) and moderate to severe cGVHD in the haplo-cord group were also lower than that in the haplo group (25.6% versus 51.3%, p = 0.019; 16.2% versus 41.3%, p = 0.016, respectively). Haplo-cord HSCT was identified as the only factor associated with a lower incidence of II–IV aGVHD and cGVHD in multivariate analysis. However, no differences were observed between the two groups for infections and survival outcomes.

Conclusion:

Our data indicated that co-infusion of UCB in ‘Beijing Protocol’-based haplo-HSCT may be effective for reducing the risk of severe GVHD in SAA children.

Fludarabine/Cyclophosphamide Conditioning Regimen in Aplastic Anemia Patients Receiving Matched-Sibling Donor Transplant Is Non-inferior to ATG/Cyclophosphamide: A Single-Center Experience from Pakistan

The successful outcome of allogeneic hematopoietic stem cell transplant (HSCT) in aplastic anemia patients is driven by suitable donor selection, appropriate conditioning regimen, early intervention, and optimal supportive care after transplant. Pakistan, being a developing country, faces grave economic challenges due to meager health care budget; therefore, cost constraints remain the foremost impediment in optimizing transplant facilities for socioeconomically deprived patients. We conducted a single-center retrospective analysis of aplastic anemia patients (N = 130), who received matched sibling donor transplants from 2011 to 2019, treated with either fludarabine/cyclophosphamide (Flu/Cy) or antithymocyte globulin/cyclophosphamide (ATG/CY) conditioning regimen. Median age was 16 years (IQR, 11-20), and it ranged from 3 to 48 years. The median time from diagnosis to transplant was 3 months (IQR, 2 to 4), and it ranged from 1 to 8 months. The estimated overall survival (OS), relapse-free survival (RFS), and GvHD-free survival (GFS) were found to be 69.0%, 66.7%, and 64.3% in the ATG/Cy group while 76.1%, 72.7%, and 62.5% in the Flu/Cy group, respectively, after a median follow-up of 30 months (IQR, 8 to 55), and it ranged from 0 to 98 months for the study groups. The Flu/Cy regimen was well tolerated and was not associated with increased risk of GvHD. Hence, it may be an appropriate alternative conditioning regimen for developing countries with limited health care resources.

The Impact of Human Microbiotas in Hematopoietic Stem Cell and Organ Transplantation

The human microbiota heavily influences most vital aspects of human physiology including organ transplantation outcomes and transplant rejection risk. A variety of organ transplantation scenarios such as lung and heart transplantation as well as hematopoietic stem cell transplantation is heavily influenced by the human microbiotas. The human microbiota refers to a rich, diverse, and complex ecosystem of bacteria, fungi, archaea, helminths, protozoans, parasites, and viruses. Research accumulating over the past decade has established the existence of complex cross-species, cross-kingdom interactions between the residents of the various human microbiotas and the human body. Since the gut microbiota is the densest, most popular, and most studied human microbiota, the impact of other human microbiotas such as the oral, lung, urinary, and genital microbiotas is often overshadowed. However, these microbiotas also provide critical and unique insights pertaining to transplantation success, rejection risk, and overall host health, across multiple different transplantation scenarios. Organ transplantation as well as the pre-, peri-, and post-transplant pharmacological regimens patients undergo is known to adversely impact the microbiotas, thereby increasing the risk of adverse patient outcomes. Over the past decade, holistic approaches to post-transplant patient care such as the administration of clinical and dietary interventions aiming at restoring deranged microbiota community structures have been gaining momentum. Examples of these include prebiotic and probiotic administration, fecal microbial transplantation, and bacteriophage-mediated multidrug-resistant bacterial decolonization. This review will discuss these perspectives and explore the role of different human microbiotas in the context of various transplantation scenarios.

Better Failure-Free Survival and Graft-versus-Host Disease-Free/Failure Free Survival with Fludarabine-Based Conditioning in Stem Cell Transplantation for Aplastic Anemia in Children

BACKGROUND

This study aimed to assess the outcome of stem cell transplantation (SCT), including overall survival (OS), failure-free survival (FFS) and graft-versus-host disease (GvHD)-free/failure-free survival (GFFS), and to analyze prognostic factors in children with aplastic anemia (AA).

METHODS

From 1991 to 2018, 43 allogeneic SCT recipients were enrolled in the study to investigate the demographic characteristics, survival outcomes and prognostic factors.

RESULTS

With the median follow-up of 7.1 years, the estimated 10-year OS, FFS, GFFS were 86.0%, 60.5%, and 51.2%, respectively. Matched related donors (MRD, n = 28) showed better 10-year OS than unrelated donors (n = 15) (96.4% vs. 66.7%; P = 0.006). Engraftment failure was seen in 13 patients (30.2%). Donor-type aplasia was seen in 13.8% (4/29) after fludarabine (Flu)-based conditioning (Flu-group), while in 42.6% (6/14) after cyclophosphamide (Cy)-based regimen (Cy-group) (P = 0.035). Six patients died. The 10-year OS in Cy-group was 92.9% (n = 14, all MRD), while that of Flu-group was 82.1% (n = 29; P = 0.367). But Flu-group tended to have better FFS and GFFS than Cy-group, although Flu-group had less MRDs (41.4% vs. 100%; P = 0.019), and higher proportion of previous immunosuppressive treatment (IST; 62% vs. 21.4%, P = 0.012). In MRD transplants, OS was similar between Flu-group (100%, n = 14) and Cy-group (92.9%, n = 14), while FFS (100.0% vs. 42.9%; P = 0.001) and GFFS (85.7% vs. 35.7%; P = 0.006) were significantly better in Flu-group. Stem cell sources, irradiation in the conditioning, and method of GvHD prophylaxis did not significantly influence the outcome.

CONCLUSION

This study reviewed SCT outcomes for pediatric AA with changes of transplant strategies over the last 25 years. The FFS and GFFS were higher in Flu-group than in Cy-group, especially in matched related transplantation. Graft failure including donor-type aplasia remains troublesome even with Flu-based conditioning. Further refinement of transplant strategies to ensure better quality-of-life should be pursued.

Mesenchymal Stem Cell Benefits Observed in Bone Marrow Failure and Acquired Aplastic Anemia

Acquired aplastic anemia (AA) is a type of bone marrow failure (BMF) syndrome characterized by partial or total bone marrow (BM) destruction resulting in peripheral blood (PB) pancytopenia, which is the reduction in the number of red blood cells (RBC) and white blood cells (WBC), as well as platelets (PLT). The first-line treatment option of AA is given by hematopoietic stem cell (HSCs) transplant and/or immunosuppressive (IS) drug administration. Some patients did not respond to the treatment and remain pancytopenic following IS drugs. The studies are in progress to test the efficacy of adoptive cellular therapies as mesenchymal stem cells (MSCs), which confer low immunogenicity and are reliable allogeneic transplants in refractory severe aplastic anemia (SAA) cases. Moreover, bone marrow stromal cells (BMSC) constitute an essential component of the hematopoietic niche, responsible for stimulating and enhancing the proliferation of HSCs by secreting regulatory molecules and cytokines, providing stimulus to natural BM microenvironment for hematopoiesis. This review summarizes scientific evidences of the hematopoiesis improvements after MSC transplant, observed in acquired AA/BMF animal models as well as in patients with acquired AA. Additionally, we discuss the direct and indirect contribution of MSCs to the pathogenesis of acquired AA.

Physicians' preferences and perceptions regarding donor selection in allogeneic stem cell transplantation in Korea when a matched domestic donor is not available

Background

A number of alternative donor options exist for patients who fail to find domestic HLA-matched donors for allogeneic hematopoietic stem cell transplantation (allo-HSCT). We assessed physicians' perspectives on allo-HSCT donor selection when a matched domestic donor is not available.

Methods

We administered a questionnaire survey to 55 hematologists (response rate: 28%) who attended the annual spring conference of the Korean Society of Haematology in 2015. The questionnaire contained four clinical allo-HSCT scenarios and the respondents were asked to choose the most preferred donor among the given options.

Results

In all four scenarios, the hematologists preferred a matched international donor over partially mismatched unrelated domestic or haplo-matched family donors. The numbers of hematologists who chose a matched international donor (HLA 8/8) in cases of acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and aplastic anemia were 37 (67.3%), 41 (74.6%), 33 (60.0%), and 36 (65.5%), respectively. The important factors that affected donor selection included “expecting better clinical outcomes (40.5%)” and “lower risk of side effects (23.4%).” The majority of participants (80%) responded that allo-HSCT guidelines for donor selection customized for the Korean setting are necessary.

Conclusion

Although hematologists still prefer perfectly matched foreign donors when a fully matched domestic allo-HSCT donor is not available, we confirmed that there was variation in their responses. For evidence-based clinical practice, it is necessary to provide further comparative clinical evidence on allo-HSCT from haplo-matched family donors and fully matched unrelated international donors.

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.

[Outcomes of very severe aplastic anemia patients with different absolute neutrophil counts after frontline immnunosuppressive therapy]

OBJECTIVE

To analyze early hematopoietic response and long-term survival of very severe aplastic anemia (VSAA) patients with different absolute neutrophil counts (ANC) after frontline immnunosuppressive therapy (IST).

METHODS

Clinical data and outcome of 145 VSAA patients treated with rabbit antithymocyte globulin combined with cyclosporine were retrospectively analyzed. Hematopoietic responses to IST and long-term survival were statistically analyzed for VSAA patients in different ANC subgroups.

RESULTS

Pre-IST ANC=0.05×10(9)/L acted as the best cutoff level to predict IST response at 3, 6 months. For 145 VSAA patients, early death rate was 13.4% (11/82) vs 1.6% (1/63), respectively, in the ANC≤0.05×10(9)/L group and ANC>0.05×10(9)/L group (P<0.05). Hematopoietic response rates to IST was 22.0% vs 54.0% (P=0.000) at 3 months, 34.1% vs 63.5% (P=0.000) at 6 months; the overall five-year survival rate was only (62.5±5.4) % vs (91.4±3.7) % (P=0.000) and five-year event-free survival rate was (42.3±5.5) % vs (63.1±6.5) % (P=0.003), respectively, in the ANC≤0.05×10(9)/L group and ANC>0.05×10(9)/L group.

CONCLUSION

VSAA patients with extremely low ANC (≤0.05×10(9)/L) had high early death rate and with very low response rate to frontline IST and poor survival, so it is urgent to seek for the alternative frontline therapy that will bring faster and better outcome for these patients.

Allogeneic hematopoietic stem cell transplantation for non-malignant hematological disorders

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) from a geno-identical matched sibling (MSD) is one of the most successful therapies in patients with non-malignant hematological disorders. This study included 273 patients with severe aplastic anemia (SAA), 152 patients with B-Thalassemia major (BTM), 31 patients with Fanconi's anemia (FA), 20 patients with congenital immunodeficiency diseases (ID), and 13 patients with inherited metabolic disorders (IMD) allografted from a MSD. In SAA, the 8-year overall survival (OS) of the whole group patients was 74%. OS was significantly better in patients conditioned with fludarabine and cyclophosphamide (Flu/Cy) than in those who received cyclophosphamide and antithymocyte globulin (Cy/ATG) (p = 0.021). Acute graft-versus-host disease (aGVHD) grade II-IV occurred in 15% while chronic GVHD (cGVHD) occurred in 28%. In BTM, the 12-year disease-free survival (DFS) of the whole group of BTM patients was 72.4%. DFS was 74% for peripheral blood stem cell (PBSC) group compared to 64% in the BM stem cell group. The incidence of graft rejection was significantly lower in patients who received PBSC than in those who received BM (9% vs 25%) (p = 0.036). AGVHD grade II-IV and cGVHD occurred in 15% and 12% of the whole group of BTM patients respectively. In FA, the 5-year OS was 64.5%. Graft rejection occurred in 10% of patients. Grade II-IV aGVHD occurred in 16% while cGVHD occurred in 4%. In ID, the 5-year OS was 62%. Graft rejection occurred in two (10%) patients. Three patients (15%) developed grade II-IV aGVHD, 2 of them progressed to secondary cGVHD. In IMD, OS was 46% at 5 years. Graft rejection occurred in 8% of patients. AGVHD grade II-IV occurred in 15% while cGVHD occurred in 14%. In conclusion, Allo-HSCT provides a higher DFS rate over conventional therapies for patients with non-malignant hematological disorders with prolonged survival.

Transplantation tolerance: from theory to clinic

Tolerance induction and alloreactivity can be applied to the clinic for the transplantation of solid organs and in the treatment of human cancers respectively. Hematopoietic chimerism, the stable coexistence of host and donor blood cells, guarantees that a solid organ from the same donor will be tolerated without a requirement for maintenance immunosuppression, and it also serves as a platform for the adoptive immunotherapy of hematologic malignancies using donor lymphocyte infusions. This review focuses on clinically relevant methods for inducing hematopoietic chimerism and transplantation tolerance, with a special emphasis on reduced intensity transplantation conditioning and high dose, post-transplantation cyclophosphamide to prevent graft rejection and graft-versus-host disease (GVHD). Reduced intensity transplantation regimens permit a transient cooperation between donor and host immune systems to eradicate malignancy without producing GVHD. Their favorable toxicity profile also enables the application of allogeneic stem cell transplantation to treat non-malignant disorders of hematopoiesis and to induce tolerance for solid organ transplantation.

Acquired aplastic anemia in children

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

Retrospective study of alemtuzumab vs ATG-based conditioning without irradiation for unrelated and matched sibling donor transplants in acquired severe aplastic anemia: a study from the British Society for Blood and Marrow Transplantation

This retrospective national study compared the use of alemtuzumab-based conditioning regimens for hematopoietic SCT (HSCT) in acquired severe aplastic anemia with antithymocyte globulin (ATG)-based regimens. One hundred patients received alemtuzumab and 55 ATG-based regimens. A matched sibling donor (MSD) was used in 87 (56%), matched unrelated donor (MUD) in 60 (39%) and other related or mismatched unrelated donor (UD) in 8 (5%) patients. Engraftment failure occurred in 9% of the alemtuzumab group and 11% of the ATG group. Five-year OS was 90% for the alemtuzumab and 79% for the ATG groups, P=0.11. For UD HSCT, OS of patients was better when using alemtuzumab (88%) compared with ATG (57%), P=0.026, although smaller numbers of patients received ATG. Similar outcomes for MSD HSCT using alemtuzumab or ATG were seen (91% vs 85%, respectively, P=0.562). A lower risk of chronic GVHD (cGVHD) was observed in the alemtuzumab group (11% vs 26%, P=0.031). On multivariate analysis, use of BM as stem cell source was associated with better OS and EFS, and less acute and cGVHD; young age was associated with better EFS and lower risk of graft failure. This large study confirms successful avoidance of irradiation in the conditioning regimens for MUD HSCT patients.

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 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.

Immunotherapy following hematopoietic stem cell transplantation: potential for synergistic effects

Hematopoietic stem cell transplantation (HSCT) is a particularly important treatment for hematologic malignancies. Unfortunately, following allogeneic HSCT, graft-versus-host disease, immunosuppression and susceptibility to opportunistic infections remain among the most substantial problems restricting the efficacy and use of this procedure, particularly for cancer. Adoptive immunotherapy and/or manipulation of the graft offer ways to attack residual cancer as well as other transplant-related complications. Recent exciting discoveries have demonstrated that HSCT could be expanded to solid tissue cancers with profound effects on the effectiveness of adoptive immunotherapy. This review will provide a background regarding HSCT, discuss the complications that make it such a complex treatment procedure following up with current immunotherapeutic strategies and discuss emerging approaches in applying immunotherapy in HSCT for cancer.

Fludarabine-based conditioning chemotherapy for allogeneic hematopoietic stem cell transplantation in acquired severe aplastic anemia

Thirty-eight patients who met the diagnostic criteria for severe aplastic anemia underwent allogeneic hematopoietic stem cell transplantation (HSCT). The median patient age was 20 years (range, 14-36 years). Twenty-four patients were treatment-naïve, 11 had failed one or more previous courses of immunosuppressive therapy, and 3 had failed a previous HSCT. The conditioning regimen included fludarabine 30 mg/m(2)/day for 3 days (days -9, -8, and -7) and cyclophosphamide 50 mg/kg/day for 4 days (days -5, -4, -3, and -2). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and short-course methotrexate. All patients underwent transplantation with unmanipulated bone marrow as the stem cell source. The median total nucleated cell (TNC) dose was 2.43 × 10(8)/kg (range, 0.60-6.7 × 10(8)/ kg). The conditioning regimen was well tolerated, with minimal treatment-related mortality. Engraftment was observed in all patients after transplantation; the median time to engraftment of neutrophils and platelets was 18 and 23 days, respectively. Twenty-five of the 27 patients with available chimeric studies at day 180 maintained donor chimerism. Acute GVHD grade ≥II was diagnosed in 4 patients (11%). Extensive chronic GVHD was observed in 8 patients (25%) who survived beyond day +100, at a median observation time of 43 months. Graft rejection with relapse of aplais was observed in one patient. The overall survival (OS) for the whole group was 79%. A trend toward improved OS was observed in the treatment-naïve patients (83% vs 71%), but this was statistically insignificant (P = .384). The fludarabine-based conditioning regimen used in this study with relatively young cohort of patients was well tolerated, with a low rate of rejection and treatment outcomes comparable to those seen in other, more intense and potentially more toxic conditioning regimens. Our results await validation in a larger study, optimally in a randomized controlled manner.

Is it time for a change? The case for early application of unrelated allo-SCT for severe aplastic anemia

Severe aplastic anemia (SAA) is a BM failure syndrome in which allo-SCT remains a highly effective curative option. Its application remains limited by donor availability and by the potential for treatment-related morbidity and mortality. The improved outcomes with unrelated transplantation are a result of the advent of molecular donor-recipient matching, generation of effective novel conditioning regimens, improvement of supportive care and expansion of the donor registry. Decision making regarding the earlier use of unrelated transplant procedures is rapidly evolving. This paper reviews critical data relevant to these treatment options and recommends early consideration of related SCT for patients with SAA who show failure of immune suppressive therapy.

Donor-derived second hematologic malignancies after cord blood transplantation

Double umbilical cord blood transplantation (UCBT) with a reduced-intensity conditioning regimen is an effective strategy for adult patients without a matched donor. The risk of second malignancies in these patients has not yet been established, however. In the present study, 98 adults with a hematologic malignancy underwent double UCBT. Seventy patients received a reduced-intensity conditioning regimen of fludarabine 30 mg/m(2)/day for 6 days, melphalan 100 mg/m(2)/day for 1 day, and rabbit antithymocyte globulin 1.5 mg/kg/day for 4 days, and 28 patients received a myeloablative total body radiation-containing conditioning regimen. Sixty-three patients received sirolimus-based graft-versus-host disease (GVHD) prophylaxis, and 35 patients received non-sirolimus-based GVHD prophylaxis. The median patient age was 48 years (range, 19-67 years). Eighteen patients developed a second malignancy at a median of 134 days after transplantation. Sixteen patients had lymphoma, and 2 patients had myelodysplasic syndrome/myeloproliferative disorder (MDS/MPD). Sixteen of these second malignancies (both cases of MDS/MPD and 14 of the lymphomas) were donor-derived; the origins of the others were not determined. GVHD prophylaxis, HLA matching, primary disease, age, total nucleated cell dose, and CD34(+) cell dose were not associated with a higher rate of second malignancy. Second myelogenous malignancies of donor origin occur after double UCBT, suggesting that a search for donor origin should be performed in all patients with suspected relapse.

Comparison of matched-sibling donor BMT and unrelated donor BMT in children and adolescent with acquired severe aplastic anemia

From January 1991 to March 2007, 61 children and adolescent with acquired severe aplastic anemia received BMT in our institutions. We retrospectively compared the outcome of 30 cases of matched-sibling donor BMT (MSD-BMT) and 31 cases of unrelated donor BMT (URD-BMT). We observed one graft failure among MSD-BMT recipients and three graft failures among URD-BMT recipients, respectively. No patients in the MSD-BMT group developed grades II-IV acute GVHD compared with 11 of 30 patients (37%) in the URD-BMT group (P<0.001). One of 30 MSD-BMT recipients (3%) developed chronic GVHD compared with 8 of 30 URD-BMT recipients (27%) (P=0.013). The incidence of EBV and CMV reactivation was 11 of 20 URD-BMT recipients and 23 of 30, respectively. One patient in the URD-BMT group died of a motor accident 5.5 years after BMT. Ten-year OS was 100% in MSD-BMT recipients and 93.8% (95% CI, 81.9-100%) in URD-BMT recipients, respectively (P=0.252). Ten-year failure-free survival was 96.7% (95% CI, 90.2-100%) in the MSD-BMT group and 84.7% (95% CI, 70.2-99.2%) in the URD-BMT group, respectively (P=0.161).

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.

Banking on cord blood stem cells

Umbilical cord blood gifted to non-profit public cord blood banks is now routinely used as an alternative source of haematopoietic stem cells for allogeneic transplantation for children and adults with cancer, bone marrow failure syndromes, haemoglobinopathies and many genetic metabolic disorders. Because of the success and outcomes of public cord banking, many companies now provide private cord banking services. However, in the absence of any published transplant evidence to support autologous and non-directed family banking, commercial cord banks currently offer a superfluous service.