Lower relapse incidence with haploidentical versus matched sibling or unrelated donor hematopoietic cell transplantation for core-binding factor AML patients in CR2: A study from the Global Committee and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended for core-binding factor mutated (CBF) AML patients achieving second complete remission (CR2). However, approximately 20% of patients may relapse after transplant and donor preference remains unclear. We compared in this EBMT global multicenter registry-based analysis the allo-HCT outcomes using either haploidentical (Haplo), matched siblings donors (MSD), or 10/10 matched unrelated donors (MUD). Data from 865 de novo adult CBF AML patients in CR2 receiving allo-HCT in 227 EBMT centers from 2010 to 2022 were analyzed, in which 329 MSD, 374 MUD, and 162 Haplo-HCTs were included. For the entire cohort, 503 (58%) patients were inv(16)/CBFB-MYH11 and 362 patients (42%) were t(8;21)/RUNX1-RUNX1T1 AML. On multivariate analysis, Haplo-HCT was associated with a lower Relapse Incidence (RI) compared to either MSD (hazard ratio [HR] = 0.56, 95% CI 0.32-0.97; p < .05) or MUD (HR = 0.57, 95% CI: 0.33-0.99, p < .05). No significant difference was observed among the 3 types of donors on LFS, OS and GRFS. CBF-AML with t(8;21) was associated with both higher RI (HR = 1.79, 95% CI 1.3-2.47; p < .01) and higher NRM (HR = 1.58, 95% CI 1.1-2.27; p < .01) than CBF-AML with inv(16), which led to worse LFS, OS and GRFS. To conclude, for CBF-AML patients in CR2, Haplo-HCTs were associated with a lower RI compared to MSD and MUD allo-HCTs. There was no difference on LFS, OS or GRFS. CBF AML patients with inv(16) had a better progonosis than those with t(8;21) after allo-HCT in CR2.

Etoposide plus cytarabine versus cyclophosphamide or melphalan in busulfan-based preparative regimens for autologous stem cell transplantation in adults with acute myeloid leukemia in first complete remission: a study from the Acute Leukemia Working Party of the EBMT

We retrospectively compared the impact of the conditioning regimen in adult patients with acute myeloid leukemia (AML) in first complete remission (CR1) that received high-dose myeloablative chemotherapy followed by autologous stem cell transplantation (ASCT) from 2010 to 2021 with either high-dose cytarabine, etoposide and busulfan (BEA), busulfan with cyclophosphamide (BUCY) or busulfan and high-dose melphalan (BUMEL) registered in the EBMT database. Overall 1560 patients underwent ASCT, of which 156, 1143 and 261 received BEA, BUCY and BUMEL, respectively. Compared to BUCY and BUMEL, BEA patients were younger (p < 0.001) and less frequently had NPM1 mutations (p = 0.03). Transplant outcomes at 5 years with BEA, BUCY and BUMEL were: cumulative incidence of relapse 41.8%, 46.6% and 51.6%; non-relapse mortality (NRM) 1.5%, 5.2% and 7.3%; probability of leukemia-free survival (LFS) 56.7%, 48.2% and 41.1%; and overall survival (OS) 71.3%, 62.3% and 56%, respectively. In multivariable analysis the BEA regimen showed significant improvement in OS compared to BUCY (hazard ratio [HR] 0.65; 95% CI, 0.42-0.83; p = 0.048) and BUMEL (HR 0.59; 95% CI, 0.37-0.94; p = 0.029). In conclusion, high-dose myeloablative combination chemotherapy with BEA offered improved outcomes compared to classical BUCY or BUMEL in patients with AML in CR1 undergoing ASCT.

History and Development of Autologous Stem Cell Transplantation for Acute Myeloid Leukemia

This review describes the development of cryopreservation, the birth of autologous stem cell transplantation (ASCT) and its past and present use to consolidate adult patients with acute myelogenous leukemia (AML). It summarizes the first autografts in patients in relapse, the experience of autografting in complete remission (CR), using bone marrow unpurged or purged in vitro with cyclophosphamide-derivatives, and the important shift to peripheral blood stem cells. The review also discusses the results of recent studies in favor of the use of ASCT to consolidate good- and intermediate-risk patients who reach CR with no detectable minimal residual disease, and those which support the inclusion of maintenance therapy post autograft with hypomethylating agents, anti-BCL-2, and, possibly, in the future, anti AML chimeric antigen receptor-T cells. Carefully applied to well-selected patients, ASCT may regain interest, because of its simplicity, its reduced toxicity, lower non-relapse mortality and better quality of life.

Non-cryopreserved hematopoietic stem cells in autograft patients with lymphoma: a matched-pair analysis comparing a single center experience with the use of cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry

BACKGROUND AIMS

Around 50 000 autologous stem cell transplantations are done each year worldwide using cryopreserved peripheral blood stem cells (PBSCs). Cryopreservation is time-consuming and expensive. Since 2007, several retrospective studies have shown that PBSCs can be stored at 4°C for 2-3 days, allowing autologous stem cell transplantation in patients with multiple myeloma receiving high-dose melphalan. Data with non-cryopreserved PBSCs in patients autografted for lymphoma following longer pre-conditioning regimens are limited. In addition, no controlled comparison has been able to detect unforeseen differences.

METHODS

The authors compared outcomes of 94 consecutive adult patients with lymphoma (66 with Hodgkin lymphoma) autografted in our department in Oran (Algeria) using PBSCs stored at 4°C, from 2009 to 2018, with patients receiving cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry. Patients autografted in Oran were matched with patients receiving cryopreserved PBSCs in the registry (four controls per patient in Oran).

RESULTS

Neutrophil engraftment was significantly faster with cryopreserved PBSCs (P = 0.003). By day 10, only 17% of patients receiving non-cryopreserved PBSCs engrafted versus 48% for cryopreserved PBSCs. Likewise, platelet recovery to 20 000/mm³ was significantly faster in patients receiving cryopreserved PBSCs (P = 0.01). However, all patients in both groups had recovered by day 20. There were no significant differences in non-relapse mortality (9% versus 7%, P = 0.4), relapse incidence (22% versus 32%, P = 0.13), progression-free survival (70% versus 61%, P = 0.4) or overall survival (85% versus 75%, P = 0.3).

CONCLUSIONS

This analysis suggests that, in patients with lymphoma receiving pre-transplant regimens such as carmustine, etoposide, cytarabine and melphalan, PBSCs stored at 4°C for up to 6 days can be used safely in centers with no cryopreservation facility. However, the kinetics of hematopoietic recovery showed a significant, albeit small, delay in engraftment for both neutrophils and platelets, which favors the use of cryopreservation if available.

Risk stratification using FLT3 and NPM1 in acute myeloid leukemia patients autografted in first complete remission

FLT3-ITD and NPM1 mutation refine prognostic stratification in acute myeloid leukemia (AML) with intermediate-risk cytogenetics. However, data on their role in patients undergoing autologous stem cell transplantation (Auto-SCT) as post-remission therapy (PRT) are limited. We therefore sought to retrospectively evaluate the role of FLT3-ITD and NPM1 in a cohort of AML patients (n = 405) with intermediate-risk cytogenetics, autografted in first complete remission (CR1). Patients were transplanted between 2000 and 2014 and reported to the European Society for Blood and Marrow Transplantation (EBMT) registry. Leukemia-free survival (LFS) was the primary outcome. Median follow-up was 5.5 years. FLT3-ITD^neg/NPM1^WT was the leading molecular subtype (50%), followed by FLT3-ITD^neg/NPM1^mut (30%). In the univariate analysis, molecular subtype was associated with LFS, overall survival (OS), and relapse incidence (RI) (p < 0.001); 5-year LFS: FLT3-ITD^neg/NPM1^mut 62%, FLT3-ITD^pos/NPM1^mut 38%, FLT3-ITD^neg/NPM1^WT 32%, and FLT3-ITD^pos/NPM1^WT 21%. At 5 years, OS and RI in the FLT3-ITD^neg/NPM1^mut subtype were 74% and 35%, respectively. The corresponding OS and RI in other subtypes were below 48% and over 57%. In a Cox multivariable model, molecular subtype was the strongest predictor of LFS, OS, and relapse. In conclusion, AML patients with intermediate-risk cytogenetics and FLT3-ITD^neg/NPM1^mut experience favorable outcomes when autografted in CR1, suggesting that Auto-SCT is a valid PRT option.

Postremission Consolidation by Autologous Hematopoietic Cell Transplantation (HCT) for Acute Myeloid Leukemia in First Complete Remission (CR) and Negative Implications for Subsequent Allogeneic HCT in Second CR: A Study by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

After autologous hematopoietic cell transplantation (HCT) in the first complete remission (CR1), patients with acute myeloid leukemia (AML) may relapse and undergo allogeneic HCT in the second complete remission (CR2). The aim of this study was to analyze the outcome of allogeneic HCT performed in CR2 comparing patients with prior consolidation by autologous HCT versus patients with chemotherapy consolidation. Included were 2619 adults with allogeneic HCT in CR2 from 2000 to 2017 with (n = 417) or without (n = 2202) prior autologous HCT. Patient groups were not entirely comparable; patients with prior autologous HCT were younger, had less often a favorable cytogenetic profile, had more commonly donors other than matched siblings, and more often received reduced-intensity conditioning. In multivariate analysis, nonrelapse mortality risks in patients with prior autologous HCT were 1.34 (1.07 to 1.67; P = .01) after adjustment for age, cytogenetic risk, transplant year, donor, conditioning intensity, sex matching, interval diagnosis-relapse, and relapse-allogeneic HCT as compared with chemotherapy consolidation. Similarly, risks of events in leukemia-free survival and graft-versus-host disease, relapse-free survival were higher with prior autologous HCT, 1.17 (1.01 to 1.35), P = .03 and 1.18 (1.03 to 1.35), P = .02, respectively. Risk of death was also higher, 1.13 (0.97 to 1.32), P = .1, but this was not significant. Postremission consolidation with autologous HCT for AML in CR1 increases toxicity of subsequent allogeneic HCT in CR2.

Optimizing the pretransplant regimen for autologous stem cell transplantation in acute myelogenous leukemia: Better outcomes with busulfan and melphalan compared with busulfan and cyclophosphamide in high risk patients autografted in first complete remission: A study from the acute leukemia working party of the EBMT

Autologous stem cell transplantation remains a clinical option to consolidate some adult patients with acute myelogenous leukemia (AML) in first complete remission (CR1). In a small cohort of patients, we have previously shown better outcomes following Busulfan and Melphalan (BUMEL) over Busulfan and Cyclophosphamide (BUCY). To identify the subpopulations that might get the highest benefit with BUMEL, we designed a larger study. All adult patients with primary AML and available cytogenetics, autografted from January 2000 to December 2016 in CR1, were included: 1137 patients received BUCY and 512 BUMEL. All factors differing in distribution between the 2 conditioning groups were introduced in multivariate analyzes. In a primary analysis, we found an interaction between conditioning and the poor risk group defined as poor cytogenetics and/or presence of the FLT3-ITD mutation. During analysis of the poor risk group, 176 patients received BUCY and 62 BUMEL. BUMEL was associated with a lower RI at 5 years (53% versus 69%, HR: 0.52, P = .002), a better Leukaemia-free survival (LFS) (42% versus 25%, HR: 0.54, P = .002) and a better OS (54% versus 36%, HR: 0.61, P = .02). During analysis of the non poor risk group, 961 patients received BUCY and 450 BUMEL. At 5 years, the RI was 50% and 47%, the LFS 45% and 48% and the OS 56% and 60% respectively, with no significant difference. We conclude that BUMEL is the preferable conditioning regimen for the poor risk leukemic patients, while in AML patients without poor risk cytogenetics or FLT3 both conditioning regimens are valid.

A comparison between allogeneic stem cell transplantation from unmanipulated haploidentical and unrelated donors in acute leukemia

BACKGROUND

In the absence of a HLA-matched related or matched unrelated donor, allogeneic stem cell transplantation (allo-SCT) from mismatched unrelated donors or haploidentical donors are potential alternatives for patients with acute leukemia with an indication to allo-SCT. The objective of this study was to compare the outcome of allo-SCT from T cell-replete haploidentical (Haplo) versus matched (MUD 10/10) or mismatched unrelated donor at a single HLA-locus (MMUD 9/10) for patients with acute leukemia in remission.

METHODS

Two hundred sixty-five adult patients with de novo acute leukemia in first or second remission that received a Haplo-SCT between January 2007 and December 2013 were compared with 2490 patients receiving a MUD 10/10 and 813 receiving a MMUD 9/10. Propensity score weighted analysis was conducted in order to control for disease risk imbalances between the groups.

RESULTS

The weighted 3-year non-relapse mortality and relapse incidence were 29 and 30% for Haplo, 21 and 29% for MUD 10/10, and 29 and 25% for MMUD 9/10, respectively. The weighted 3-year leukemia-free survival (LFS) and overall survival (OS) were 41 and 46% for Haplo, 50 and 56% for MUD 10/10, and 46 and 48% for MMUD 9/10, respectively. Using weighted Cox model, both LFS and OS were significantly higher in transplants from MUD 10/10 compared from those in Haplo but not different between transplants from MMUD 9/10 and Haplo. The type of donor was not significantly associated with neither acute nor chronic graft-versus-host disease.

CONCLUSIONS

Patients with acute leukemia in remission have better outcomes if transplanted from a MUD 10/10. We did not find any significant difference in outcome between transplants from MMUD 9/10 and Haplo, suggesting that both can be equally used in the absence of a 10/10 MUD. KEY POINT 1: Better outcomes using fully (10/10) matched unrelated donor for allo-SCT in acute leukemia in remission. KEY POINT 2: Similar outcomes after allo-SCT from unmanipulated haploidentical graft or mismatched (9/10) unrelated donor in acute leukemia in remission.

Anti-thymocyte globulin as graft-versus-host disease prevention in the setting of allogeneic peripheral blood stem cell transplantation: a review from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Allogeneic hematopoietic stem cell transplantation is increasingly used as treatment for patients with life-threatening blood diseases. Its curative potential is largely based on immune-mediated graft-versus-leukemia effects caused by donor T cells contained in the graft. Unfortunately, donor T cells are also the cause of graft-versus-host disease. The vast majority of human leukocyte antigen-matched allogeneic hematopoietic stem cell transplants are nowadays carried out with peripheral blood stem cells as the stem cell source. In comparison with bone marrows, peripheral blood stem cells contain more hematopoietic stem/progenitor cells but also one log more T cells. Consequently, the use of peripheral blood stem cells instead of bone marrow has been associated with faster hematologic recovery and a lower risk of relapse in patients with advanced disease, but also with a higher incidence of chronic graft-versus-host disease. These observations have been the basis for several studies aimed at assessing the impact of immunoregulation with anti-thymocyte globulin on transplantation outcomes in patients given human leukocyte antigen-matched peripheral blood stem cells from related or unrelated donors. After a brief introduction on anti-thymocyte globulin, this article reviews recent studies assessing the impact of anti-thymocyte globulin on transplantation outcomes in patients given peripheral blood stem cells from human leukocyte antigen-matched related or unrelated donors as well as in recipients of grafts from human leukocyte antigen haploidentical donors.

Expanding transplant options to patients over 50 years. Improved outcome after reduced intensity conditioning mismatched-unrelated donor transplantation for patients with acute myeloid leukemia: a report from the Acute Leukemia Working Party of the EBMT

The outcome of patients undergoing HLA-matched unrelated donor allogeneic hematopoietic cell transplantation following reduced-intensity conditioning or myeloablative regimens is reported to be equivalent; however, it is not known if the intensity of the conditioning impacts outcomes after mismatched unrelated donor transplantation for acute myeloid leukemia. Eight hundred and eighty three patients receiving reduced-intensity conditioning were compared with 1041 myeloablative conditioning regimen recipients in the setting of mismatched unrelated donor transplantation. The donor graft was HLA-matched at 9/10 in 872 (83.8%) and at 8/10 in 169 (16.2%) myeloablative conditioning recipients, while in the reduced-intensity conditioning cohort, 754 (85.4%) and 129 (14.6%) were matched at 9/10 and 8/10 loci, respectively. Myeloablative conditioning regimen recipients were younger, 70% being <50 years of age compared to only 30% in the reduced-intensity conditioning group (P=0.0001). Significantly, more patients had secondary acute myeloid leukemia (P=0.04) and Karnofsky Performance Status score <90% (P=0.02) in the reduced-intensity conditioning group. Patients <50 and ≥50 years were analyzed separately. On multivariate analysis and after adjusting for differences between the two groups, reduced-intensity conditioning in patients age ≥50 years was associated with higher overall survival (HR 0.78; P=0.01), leukemia-free survival (HR 0.82; P=0.05), and decreased non-relapse mortality (HR 0.73; P=0.03). Relapse incidence (HR 0.91; P=0.51) and chronic graft-versus-host disease (HR 1.31; P=0.11) were, however, not significantly different. In patients <50 years old, there were no statistically significant differences in overall survival, leukemia-free survival, relapse incidence, non-relapse mortality, and chronic graft-versus-host-disease between the groups. Our study shows no significant outcome differences in patients younger than 50 years receiving reduced-intensity vs myeloablative conditioning regimens after mismatched unrelated donor transplantation. Furthermore, the data support the superiority of reduced-intensity conditioning regimens in older adults receiving transplants from mismatched unrelated donors.

Prediction of Hematopoietic Stem Cell Transplantation Related Mortality- Lessons Learned from the In-Silico Approach: A European Society for Blood and Marrow Transplantation Acute Leukemia Working Party Data Mining Study

Models for prediction of allogeneic hematopoietic stem transplantation (HSCT) related mortality partially account for transplant risk. Improving predictive accuracy requires understating of prediction limiting factors, such as the statistical methodology used, number and quality of features collected, or simply the population size. Using an in-silico approach (i.e., iterative computerized simulations), based on machine learning (ML) algorithms, we set out to analyze these factors. A cohort of 25,923 adult acute leukemia patients from the European Society for Blood and Marrow Transplantation (EBMT) registry was analyzed. Predictive objective was non-relapse mortality (NRM) 100 days following HSCT. Thousands of prediction models were developed under varying conditions: increasing sample size, specific subpopulations and an increasing number of variables, which were selected and ranked by separate feature selection algorithms. Depending on the algorithm, predictive performance plateaued on a population size of 6,611–8,814 patients, reaching a maximal area under the receiver operator characteristic curve (AUC) of 0.67. AUCs’ of models developed on specific subpopulation ranged from 0.59 to 0.67 for patients in second complete remission and receiving reduced intensity conditioning, respectively. Only 3–5 variables were necessary to achieve near maximal AUCs. The top 3 ranking variables, shared by all algorithms were disease stage, donor type, and conditioning regimen. Our findings empirically demonstrate that with regards to NRM prediction, few variables “carry the weight” and that traditional HSCT data has been “worn out”. “Breaking through” the predictive boundaries will likely require additional types of inputs.

Autologous stem cell transplantation versus alternative allogeneic donor transplants in adult acute leukemias

The availability of alternative sources of stem cells including most recently T-replete haploidentical marrow or peripheral blood, and the increasing use of reduced-intensity conditioning (RIC), renders feasible an allogeneic transplant to almost all patients with acute leukemia up to 70 years of age. Autologous stem cell transplantation (ASCT) for consolidation of complete remission (CR), however, offers in some circumstances an alternative option. Although associated with a higher relapse rate, autologous transplant benefits from a lower non-relapse mortality, the absence of graft-versus-host disease (GVHD), and a better quality of life for long-term survivors. The recent use of intravenous busulfan (IVBU) with high-dose melphalan, better monitoring of minimal residual disease (MRD), and maintenance therapy post autografting bring new interest. Few retrospective studies compared the outcome following alternative donor versus autologous transplants for remission consolidation. Genoidentical and phenoidentical allogeneic stem cell transplantations are undisputed gold standards, but there are no data showing the superiority of alternative allogeneic donor over autologous transplantation, at the time of undetectable MRD, in patients with good- and intermediate-1 risk acute myelocytic leukemia (AML) in first complete remission (CR1), acute promyelocytic leukemia in second complete remission (CR2), and Philadelphia chromosome-positive (Ph(+)) acute lymphocytic leukemia (ALL).

Autologous hematopoietic stem cell transplantation in elderly patients (≥ 70 years) with non-Hodgkin's lymphoma: A French Society of Bone Marrow Transplantation and Cellular Therapy retrospective study

INTRODUCTION

Limited data is available on the feasibility of high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (AHSCT) in elderly patients over 70 years of age with non-Hodgkin's lymphoma (NHL).

MATERIALS AND METHODS

In the setting of the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) group, we retrospectively analyzed 81 consecutive patients with NHL over 70 years of age who received AHSCT.

RESULTS

The median age at AHSCT was 72.3 years [70-80]. Patients' were diagnosed with diffuse large B-cell lymphoma (n=40), follicular lymphoma (n=16), mantle cell lymphoma (n=15), T-cell lymphoma (n=5), and other (n=5). Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) was 0 in 73% of patients. Main conditionings were BEAM (Carmustine-Etoposide-Cytarabine-Melphalan, n=61) and melphalan alone (n=14). Median delays to reach 0.5×10⁹/L neutrophils and 20 × 10(9)/L platelets were of 12 [9-76] days and 12 [0-143] days, respectively. One hundred day and one year cumulative incidence of NRM was 5.4% and 8.5%, respectively. The main cause of death remains relapse.

CONCLUSION

In conclusion, this study revealed that AHSCT seemed to be acceptable in patients over 70 years of age with NHL. Patient age is not a limiting factor if clinical condition is adequate.

Lymphomas of the spleen and bone marrow lymphoid nodules

Many nodular primitive non-Hodgkin's lymphomas of the spleen have a favourable course after splenectomy or chemotherapy. Several observations of this type have been reported in the literature, in which the concept of malignancy is discussed, authors referring to a presarcomatous state or to an idiopathic splenomegaly. The evaluation of the extension of those sarcomas, however, very often show hepatic lesions, and always an increase in the lymphoid marrow nodules. The significance of these nodules is discussed here, with reference to 14 personal observations. These nodules may not always reflect a real extension of the sarcoma to the marrow. From a practical point of view, the presence of lymphoid marrow nodules, when associated with an isolated splenomegaly, is a strong argument to suspect a sarcoma of the spleen, and indicates a splenectomy.

Lenalidomide consolidation and maintenance therapy after autologous stem cell transplant for multiple myeloma induces persistent changes in T-cell homeostasis

Whether the efficacy of lenalidomide in the treatment of multiple myeloma (MM) is due to direct tumor toxicity only or to additional immunomodulatory effects is unclear. We studied the effect of lenalidomide treatment on T-cell immune reconstitution in patients with MM who had undergone autologous peripheral blood stem cell transplant (ASCT). Twenty-nine newly diagnosed patients with MM received induction therapy followed by high-dose melphalan and ASCT. After ASCT, 11 patients received lenalidomide consolidation therapy for 2 months followed by maintenance therapy until disease progression. The remaining 18 patients received no treatment. Serial analysis of thymic output, as given by numbers of T-cell receptor excision circles (sjTRECs), and T-cell phenotyping was performed until 18 months post-ASCT. Lenalidomide impaired long-term thymic T-cell reconstitution, decreased CD4 + and CD8 + CD45RA + CCR7 - effector-terminal T-cell absolute counts and increased CD4 + CD25 + CD127 - /low regulatory T-cells. Lenalidomide consolidation and long-term maintenance therapy, administered post-ASCT, may have a potentially negative impact on immune surveillance.

Improving results of autologous stem cell transplantation for Philadelphia-positive acute lymphoblastic leukaemia in the era of tyrosine kinase inhibitors: a report from the Acute Leukaemia Working Party of the European Group for Blood and Marrow Transplantation

BACKGROUND

Outcome of Philadelphia-positive acute lymphoblastic leukaemia (Ph+ ALL) improved significantly with the introduction of tyrosine kinase inhibitors (TKIs). Autologous stem cell transplantation (ASCT) has never been considered a standard of care in this setting. The aim of our study was to analyse if results of ASCT improved in the era of TKIs.

PATIENTS AND METHODS

One-hundred and seventy-seven adults with Ph+ ALL treated with ASCT in first complete remission were analysed for the impact of year of transplantation on outcome. Additional analysis was performed including 32 patients for whom detailed data on the use of TKIs and the status of minimal residual disease were collected.

RESULTS

The probability of the overall survival (OS) at 3 years increased from 16% for transplants performed between 1996 and 2001 to 48% between 2002 and 2006 and 57% between 2007 and 2010 (P<.0001). Leukaemia-free survival (LFS) was 11%, 39% and 52%, respectively (P<.0001). Relapse incidence decreased from 70% to 45% and 45% (P=.01), respectively, while non-relapse mortality was 19%, 15% and 3% (P=.08). In a multivariate analysis, year of ASCT was the only independent factor influencing the risk of treatment failure (hazard ratio (HR)=0.37; P<.001). In a subgroup of 22 patients actually treated with TKIs and being in complete molecular remission at the time of ASCT, the LFS rate at 3 years was 65%.

CONCLUSIONS

Results of ASCT for Ph+ ALL improved significantly over time. Prospective, innovative studies are needed to verify the role of ASCT in this patient setting.

Cost-effectiveness and clinical outcomes of double versus single cord blood transplantation in adults with acute leukemia in France

Double cord blood transplantation extends the use of cord blood to adults for whom a single unit is not available, but the procedure is limited by its cost. To evaluate outcomes and cost-effectiveness of double compared to single cord blood transplantation, we analyzed 134 transplants in adults with acute leukemia in first remission. Transplants were performed in France with reduced intensity or myeloablative conditioning regimens. Costs were estimated from donor search to 1 year after transplantation. A Markov decision analysis model was used to calculate quality-adjusted life-years and cost-effectiveness ratio within 4 years. The overall survival at 2 years after single and double cord blood transplants was 42% versus 62%, respectively (P=0.03), while the leukemia-free-survival was 33% versus 53%, respectively (P=0.03). The relapse rate was 21% after double transplants and 42% after a single transplant (P=0.006). No difference was observed for non-relapse mortality or chronic graft-versus-host-disease. The estimated costs up to 1 year after reduced intensity conditioning for single and double cord blood transplantation were € 165,253 and €191,827, respectively. The corresponding costs after myeloablative conditioning were € 192,566 and € 213,050, respectively. Compared to single transplants, double cord blood transplantation was associated with supplementary costs of € 21,302 and € 32,420 up to 4 years, but with increases in quality-adjusted life-years of 0.616 and 0.484, respectively, and incremental cost-effectiveness ratios of € 34,581 and €66,983 in the myeloablative and reduced intensity conditioning settings, respectively. Our results showed that for adults with acute leukemia in first complete remission in France, double cord transplantation is more cost-effective than single cord blood transplantation, with better outcomes, including quality-adjusted life-years.

Superiority of the Triple Combination of Bortezomib-Thalidomide-Dexamethasone Over the Dual Combination of Thalidomide-Dexamethasone in Patients With Multiple Myeloma Progressing or Relapsing After Autologous Transplantation: The MMVAR/IFM 2005-04 Randomized Phase III Trial From the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Purpose

This prospective multicenter phase III study compared the efficacy and safety of a triple combination (bortezomib-thalidomide-dexamethasone [VTD]) versus a dual combination (thalidomide-dexamethasone [TD]) in patients with multiple myeloma (MM) progressing or relapsing after autologous stem-cell transplantation (ASCT).

Patients and Methods

Overall, 269 patients were randomly assigned to receive bortezomib (1.3 mg/m2 intravenous bolus) or no bortezomib for 1 year, in combination with thalidomide (200 mg per day orally) and dexamethasone (40 mg orally once a day on 4 days once every 3 weeks). Bortezomib was administered on days 1, 4, 8, and 11 with a 10-day rest period (day 12 to day 21) for eight cycles (6 months), and then on days 1, 8, 15, and 22 with a 20-day rest period (day 23 to day 42) for four cycles (6 months).

Results

Median time to progression (primary end point) was significantly longer with VTD than TD (19.5 v 13.8 months; hazard ratio, 0.59; 95% CI, 0.44 to 0.80; P = .001), the complete response plus near-complete response rate was higher (45% v 21%; P = .001), and the median duration of response was longer (17.9 v 13.4 months; P = .04). The 24-month survival rate was in favor of VTD (71% v 65%; P = .093). Grade 3 peripheral neuropathy was more frequent with VTD (29% v 12%; P = .001) as were the rates of grades 3 and 4 infection and thrombocytopenia.

Conclusion

VTD was more effective than TD in the treatment of patients with MM with progressive or relapsing disease post-ASCT but was associated with a higher incidence of grade 3 neurotoxicity.

European consensus on the medical management of acute radiation syndrome and analysis of the radiation accidents in Belgium and Senegal

A European consensus concerning the medical management of mass radiation exposure was obtained in 2005 during a conference held by the European Group for Blood and Bone Marrow Transplantation, the Institute of Radioprotection and Nuclear Safety, and the University of Ulm. At the conference, a two-step triage strategy to deal with large masses of radiation-exposed patients was designed. The first step of this strategy concerns the first 48 h and involves scoring the patients exclusively on the basis of their clinical symptoms and biological data. This allows the non-irradiated bystanders and outpatient candidates to be identified. The remaining patients are hospitalized and diagnosis is confirmed after the first 48-h period according to the METREPOL (Medical Treatment Protocols for radiation accident victims) scale. This grades the patients according to the severity of their symptoms. It was also agreed that in the case of acute radiation syndrome (ARS), emergency hematopoietic stem cell (HSC) transplantation is not necessary. Instead, cytokines that promote hematological reconstruction should be administered as early as possible for 14-21 d. Crucial tests for determining whether the patient has residual hematopoiesis are physical dose reconstructions combined with daily blood count analyses. It was agreed that HSC transplantation should only be considered if severe aplasia persists after cytokine treatment. Two recent cases of accidental radiation exposure that were managed successfully by following the European consensus with modification are reviewed here. Thus, a European standard for the evaluation and treatment of ARS victims is now available. This standard may be suitable for application around the world.

High-dose therapy and autologous stem-cell transplantation in Waldenstrom macroglobulinemia: the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

PURPOSE

The role of autologous stem-cell transplantation (ASCT) in Waldenström macroglobulinemia (WM) is not defined. The aim of this study was to analyze the results of ASCT in patients with WM and to determine the prognostic factors that have a significant impact on outcome.

PATIENTS AND METHODS

We analyzed 158 adult patients with WM reported to the European Group for Blood and Marrow Transplantation (EBMT) between January 1991 and December 2005. Median time from diagnosis to ASCT was 1.7 years (range, 0.3 to 20.3 years), 32% of the patients experienced treatment failure with at least three lines of therapy, and 93% had sensitive disease at the time of ASCT. Conditioning regimen was total-body irradiation-based in 45 patients. Median follow-up for surviving patients was 4.2 years (range, 0.5 to 14.8 years).

RESULTS

Nonrelapse mortality was 3.8% at 1 year. Ten patients developed a secondary malignancy, with a cumulative incidence of 8.4% at 5 years. Relapse rate was 52.1% at 5 years. Progression-free survival (PFS) and overall survival were 39.7% and 68.5%, respectively, at 5 years and were significantly influenced by number of lines of therapy and chemorefractoriness at ASCT. The achievement of a negative immunofixation after ASCT had a positive impact on PFS after ASCT. When used as consolidation at first response, ASCT provided a PFS of 44% at 5 years.

CONCLUSION

ASCT is a feasible procedure in young patients with advanced WM. ASCT should not be offered to patients with chemoresistant disease and to those who received more than three lines of therapy.

Unimpaired terminal erythroid differentiation and preserved enucleation capacity in myelodysplastic 5q(del) clones: a single cell study

BACKGROUND

Anemia is a characteristic of myelodysplastic syndromes, such as the rare 5q- syndrome, but its mechanism remains unclear. In particular, data are lacking on the terminal phase of differentiation of erythroid cells (enucleation) in myelodysplastic syndromes.

DESIGN AND METHODS

We used a previously published culture model to generate mature red blood cells in vitro from human hematopoietic progenitor cells in order to study the pathophysiology of the 5q- syndrome. Our model enables analysis of cell proliferation and differentiation at a single cell level and determination of the enucleation capacity of erythroid precursors.

RESULTS

The erythroid commitment of 5q(del) clones was not altered and their terminal differentiation capacity was preserved since they achieved final erythroid maturation (enucleation stage). The drop in red blood cell production was secondary to the decrease in the erythroid progenitor cell pool and to impaired proliferative capacity. RPS14 gene haploinsufficiency was related to defective erythroid proliferation but not to differentiation capacity.

CONCLUSIONS

The 5q- syndrome should be considered a quantitative rather than qualitative bone marrow defect. This observation might open the way to new therapeutic concepts.

Feasibility and limits of bone marrow mononuclear cell expansion following irradiation

PURPOSE

To define the ability of bone marrow mononuclear cells (BMMNC) to expand after irradiation and to determine the amount of apoptosis in irradiated expanded cells.

MATERIALS AND METHODS

Non-human primate BMMNC were irradiated in vitro at doses ranging from 0 to 4 Gy and were cultured during 1 week in the presence of interleukin 3, interleukin 6, stem cell factor, thrombopoietin and fms-like tyrosine kinase-3 ligand. The expansion yield of BMMNC, colony-forming cells and CD34(+) cells were compared with non-irradiated control cultures. Apoptosis in expanded cells was also defined by annexin V/propidium iodine staining.

RESULTS

Irradiation of BMMNC up to 1 Gy did not modify the ability of haematopoietic cells to expand. At higher doses, expansion of haematopoietic cells is reduced as compared with non-irradiated cultures but it remains significant. This reduction in expansion of BMMNC was related to radiation-induced apoptosis.

CONCLUSION

The results suggest that it is possible to expand haematopoietic cells after irradiation doses at least up to 2 Gy. This suggests a possible use of cell therapy for the treatment of radiation accident victims.

Simultaneous occurrence of clinical manifestations of myeloma and Waldenström's macroglobulinemia with monoclonal IgG Lambda and IgM Kappa in a single patient

This paper reports a rare case of a patient with biclonal gammopathy IGM kappa and IgG lambda corresponding to the simultaneous occurrence of the clinical manifestations of Waldenström's macroglobulinemia and multiple myeloma. Two cellular populations derived from the B lymphocyte cell line can be observed in this patient. Bone marrow aspiration revealed abnormal plasma cells with inclusions and lymph node aspiration showed immature lymphoid cells containing mu heavy chains.

Waldenström's macroglobulinemia in monozygotic twins

This paper reports a unique familial occurrence of Waldenström's macroglobulinemia (WM) in monozygotic twins. The determination of twin monozygosity has been performed by electrophoretic and immunological typing of genetic systems (erythrocyte blood groups, leucocyte antigens and serum protein polymorphism). The two monoclonal IgM differ one from the other by their light chain type and their idiotypic determinants. Although a genetic predisposition to WM exists in these twins, the gene recombination leading to idiotypic specificity and light chain assortment occurs independently of the monoclonal malignant involvement.

Selected Stro-1-enriched bone marrow stromal cells display a major suppressive effect on lymphocyte proliferation

Mesenchymal stem cells (MSCs) have an immunosuppressive effect and can inhibit the proliferation of alloreactive T cells in vitro and in vivo. Cotransplantation of MSCs and hematopoietic stem cells (HSCs) from HLA-identical siblings has been shown to reduce the incidence of acute graft-vs.-host disease. MSCs are heterogeneous and data on the inhibitory effects of different MSC subsets are lacking. The antigen Stro1 is a marker for a pure primitive MSC subset. We investigated whether Stro-1-enriched induce a more significant suppressive effect on lymphocytes in a mixed lymphocyte reaction (MLR), and whether this action is related to a specific gene expression profile in Stro-1-enriched compared to other MSCs. We demonstrated that the Stro-1-enriched population elicits a significantly more profound dose-dependent inhibition of lymphocyte proliferation in a MLR than MSCs. One thousand expanded Stro-1-enriched induced an inhibitory effect comparable to that of 10 times as many MSCs. Inhibition by Stro-1-enriched was more significant in contact-dependent cultures than in noncontact-dependant cultures at higher ratio. The Stro-1-enriched inhibitory effect in both culture types was linked to increased gene expression for soluble inhibitory factors such as interleukin-8 (IL-8), leukemia inhibitory factor (LIF), indoleamine oxidase (IDO), human leukocyte antigen-G (HLA-G), and vascular cell adhesion molecule (VCAM1). However, tumor growth factor-beta1 (TGF-beta) and IL-10 were only up-regulated in contact-dependant cultures. These results may support using a purified Stro-1-enriched population to augment the suppressive effect in allogeneic transplantation.

Mesenchymal stem cell abnormalities in patients with multiple myeloma

Osteolytic bone lesions are common in patients with multiple myeloma (MM), a clonal plasma cell disorder, and result from increased osteoclastic bone resorption and decreased osteoblastic bone formation. Because mesenchymal stem cells (MSCs) are committed towards cells of the osteoblast lineage, we compared the in vitro characteristics of MSCs from the bone marrow of 18 MM patients (MM-MSCs) and eight normal donors (ND-MSCs). MM-MSCs displayed deficient growth that could be explained in part by the reduced expression of several growth factor receptors on the surface of MM-MSCs compared with ND-MSCs. Receptor downregulation was observed on RT-PCR analysis. A major finding was an approximately fivefold higher expression of osteoblast inhibitor DKK1 at transcript and protein levels in MM-MSCs than ND-MSCs. These data suggest that defective osteoblast function in patients with advanced MM may be related not only to factors released by tumor myeloma cells but also to MSC abnormalities.

Simultaneous regression of Philadelphia chromosome and multiple nonrecurrent clonal chromosomal abnormalities with imatinib mesylate in a patient autografted 22 years before for chronic myelogenous leukemia

A 31-year-old patient developed chronic myelogenous leukemia (CML) in November, 1983. In November 1984, following a diagnosis of acceleration, he received an autologous hemopoietic transplant after conditioning with cyclophosphamide and total body irradiation. The autologous marrow was purged with mafosfamide. Over 20 years, the patient remained in chronic phase of CML. Multiple nonrecurrent clonal chromosomal abnormalities appeared leading to a very complex karyotype, including among others involvement of chromosomes 1, 7, 9, 13, 19, and X. Fluorescent in situ hybridization showed that the two chromosomes 9 were involved. Acute myeloid crisis was diagnosed in February, 2004. Treatment with imatinib mesylate resulted within 6 months in a total disappearance of all chromosomal abnormalities with a complete cytogenetic and molecular response, which persists 3 years later. We question whether the ex vivo purging procedure with mafosfamide has favored the occurrence of these particular cytogenetic abnormalities (with no independent oncogenic potential) within the original leukemic stem cell pool. It remains unclear whether the autologous transplantation has indeed resulted into some prolongation of the duration of the chronic phase, which lasted for 20 years. At time of acute crisis, the dramatic response to imatinib mesylate leading to a complete cytogenetic and molecular response is noteworthy.

Two successful pregnancies in a chronic myeloid leukemia patient treated with imatinib

The number of CML patients in child-bearing age and treated with imatinib is increasing. These women may want to be pregnant or are actually pregnant while on imatinib. Physicians do not know when to stop the treatment and what the risks are for the foetus and the mother. We report a case of a CML patient treated with imatinib who has two children, now 3 years and 10 months of age, in good health. The mother was in complete molecular remission, relapsed during pregnancy and reverted to remission in both cases after delivery.

HLA-identical sibling allogeneic peripheral blood stem cell transplantation with reduced intensity conditioning compared to autologous peripheral blood stem cell transplantation for elderly patients with de novo acute myeloid leukemia

We conducted a retrospective registry-based analysis to compare the outcome of 361 allogeneic human leukocyte antigen (HLA)-identical peripheral blood stem cell transplants (PBSCT) with reduced intensity conditioning (RIC) to that of 1369 autologous (auto) PBSCT in patients aged 50 years or older with de novo acute myeloid leukemia (AML), performed from 1997 until 2003 and reported to the European Group for Blood and Marrow Transplantation. Median age was 58 and 57 years in the RIC and auto groups, respectively. RIC patients had more advanced disease at the time of transplant. At a median follow-up of 24 months for RIC and 16 months for auto, multivariate analysis showed a lower risk for relapse (RR 0.77, P=0.013) without increased non-relapse mortality (NRM) in RIC patients (RR 1.26, P=0.28). Moreover, leukemia-free survival (RR 1.22, P=0.02) and overall survival (OS) (RR 1.32, P=0.005) were superior in the RIC group. In patients in 1st (CR), fewer relapses were counterbalanced by significantly increased NRM. Therefore, there was no survival advantage in this subgroup. In patients in 2nd or subsequent CR, LFS and OS were superior in the RIC group. RIC transplants show encouraging results in this older patient population with de novo AML.

'Indolent' Waldenstrom's macroglobulinemia and a cerebrospinal fluid protein level of 16 g/L

Waldenstrom's macroglobulinemia occasionally presents with neurological manifestations. Very rarely, it is due to a central nervous system localization, the so-called Bing Neel Syndrome. We report a patient with an 'indolent' systemic disease and surprisingly a concomitant major CNS involvement.

Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic haematopoietic stem cell transplantation for patients older than 50 years of age with acute myeloblastic leukaemia: a retrospective survey from the Acute Leukemia Working Party (ALWP) of the European group for Blood and Marrow Transplantation (EBMT)

Results of reduced intensity conditioning regimen (RIC) in the HLA identical haematopoietic stem cell transplantation (HSCT) setting have not been compared to those after myeloablative (MA) regimen HSCT in patients with acute myeloblastic leukaemia (AML) over 50 years of age. With this aim, outcomes of 315 RIC were compared with 407 MA HSCT recipients. The majority of RIC was fludarabine-based regimen associated to busulphan (BU) (53%) or low-dose total body irradiation (24%). Multivariate analyses of outcomes were used adjusting for differences between both groups. The median follow-up was 13 months. Cytogenetics, FAB classification, WBC count at diagnosis and status of the disease at transplant were not statistically different between the two groups. However, RIC patients were older, transplanted more recently, and more frequently with peripheral blood allogeneic stem cells as compared to MA recipients. In multivariate analysis, acute GVHD (II-IV) and transplant-related mortality were significantly decreased (P=0.01 and P<10(-4), respectively) and relapse incidence was significantly higher (P=0.003) after RIC transplantation. Leukaemia-free survival was not statistically different between the two groups. These results may set the grounds for prospective trials comparing RIC with other strategies of treatment in elderly AML.

Homing of in vitro expanded Stro-1- or Stro-1+ human mesenchymal stem cells into the NOD/SCID mouse and their role in supporting human CD34 cell engraftment

The Stro-1 antigen potentially defines a mesenchymal stem cell (MSC) progenitor subset. We here report on the role of human ex vivo-expanded selected Stro-1(+) or Stro-1(-) MSC subsets on the engraftment of human CD34(+) cord blood cells in the nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mouse model. The data show that cotransplantation of expanded Stro-1(-) cells with CD34(+) cells resulted in a significant increase of human CD45, CD34, CD19, and CD11b cells detected in blood or in bone marrow (BM) and spleen as compared with the infusion of CD34(+) cells alone. Infusion into mice of expanded Stro-1(+) and Stro-1(-) cells (without CD34(+) cells) showed that the numbers of Stro-1(+)-derived (as assessed by DNA analysis of human beta-globin with quantitative polymerase chain reaction [PCR]) were higher than Stro-1(-)-derived cells in spleen, muscles, BM, and kidneys, while more Stro-1(-)-derived than Stro-1(+)-derived cells were found in lungs. The transduction of expanded Stro-1(+) cells with an enhanced green fluorescent protein (eGFP) gene did not modify their cytokine release and their homing in NOD/SCID mouse tissues. The difference between the hematopoietic support and the homing capabilities of expanded Stro-1(+) and Stro-1(-) cells may be of importance for clinical therapeutic applications: Stro-1(+) cells may rather be used for gene delivery in tissues while Stro-1(-) cells may rather be used to support hematopoietic engraftment.

Plasma Flt-3 ligand concentration correlated with radiation-induced bone marrow damage during local fractionated radiotherapy

PURPOSE

To determine whether variations in the plasma Flt-3 ligand (FL) concentration after radiotherapy (RT) may serve as a biomarker for radiation-induced bone marrow damage.

METHODS AND MATERIALS

Twenty-seven patients were followed during RT. The irradiated bone marrow volume was determined. The blood cell counts and plasma FL concentrations were evaluated before and after RT. The expression of membrane-bound FL and mRNA expression were also defined in circulating blood cells.

RESULTS

We found a negative correlation between the plasma FL concentration and the number of circulating white blood cells and platelets during RT. Moreover, the overall amount of FL in the blood of patients during RT correlated directly with both the cumulated radiation dose and the proportion of irradiated bone marrow.

CONCLUSIONS

We demonstrated that the variations in plasma FL concentration directly reflect the radiation-induced bone marrow damage during fractionated local RT. We suggest a possible use for FL monitoring as a means to predict the occurrence of Grade 3-4 leukopenia or thrombocytopenia during the course of RT.

Mesenchymal stem cells home to injured tissues when co-infused with hematopoietic cells to treat a radiation-induced multi-organ failure syndrome

BACKGROUND

Recent studies have suggested that ex vivo expansion of autologous hematopoietic cells could be a therapy of choice for the treatment of bone marrow failure. We investigated the potential of a combined infusion of autologous ex vivo expanded hematopoietic cells with mesenchymal (MSCs) for the treatment of multi-organ failure syndrome following irradiation in a non-human primate model.

METHODS

Hematopoietic cells and MSCs were expanded from bone marrow aspirates. MSCs were transduced with the gene encoding for the green fluorescent protein (e-GFP), in order to track them following infusion. Twelve animals were studied. Nine animals received total-body irradiation at 8 Gy from a neutron/gamma source thus resulting in heterogeneous exposure; three animals were sham-irradiated. The animals were treated with expanded hematopoietic stem cells and MSCs, expanded hematopoietic stem cells alone, or MSCs alone. Unmanipulated bone marrow cell transplants were used as controls.

RESULTS

Depending on the neutron/gamma ratio, an acute radiation sickness of varying severity but of similar nature resulted. GFP-labeled cells were found in the injured muscle, skin, bone marrow and gut of the treated animals via PCR up to 82 days post-infusion.

CONCLUSIONS

This is the first evidence of expanded MSCs homing in numerous tissues following a severe multi-organ injury in primates. Localization of the transduced MSCs correlated to the severity and geometry of irradiation. A repair process was observed in various tissues. The plasticity potential of the MSCs and their contribution to the repair process in vivo remains to be studied.

Patients with acute lymphoblastic leukaemia allografted with a matched unrelated donor may have a lower survival with a peripheral blood stem cell graft compared to bone marrow

We analysed data for 213 patients with ALL and AML who received either peripheral blood stem cells (PBSC) (n=74) or bone marrow (BM) (n=139) from an HLA-matched unrelated donor (EBMT acute leukaemia registry; January 1994 to January 1999). The two groups of patients (by cell source) were comparable with respect to age, sex, disease status, year at transplant and graft T cell depletion. Engraftment was achieved in about 90% regardless of stem cell source or leukaemia type. Kinetics of neutrophil and platelet recovery, similar for both sources in ALL patients, were faster for PBSC in AML patients. The incidence of acute graft-versus-host disease was similar for both sources in AML patients, but higher for PBSC in ALL patients (74 vs 54%, P=0.05). The 1-year probability of chronic graft-versus-host disease was 40 and 45% (P=0.66) in ALL patients compared to 49 and 35% (P=0.13) in AML patients (PBSC vs BM). In AML patients, none of the following differed significantly with cell source: transplant-related mortality, relapse incidence, leukaemia-free survival and overall survival. In ALL patients, the transplant-related mortality for PBSC vs BM was 61 vs 47% (P=0.13), the relapse incidence was 47 vs 39% (P=0.17), the leukaemia-free survival was 21 vs 32% (P=0.04) and the overall survival was 24 vs 34% (P=0.04). These data suggest that the short-term outcome of allogeneic PBSC is not significantly different from that of BM in AML patients who underwent a transplant from a matched unrelated donor but, conversely, that survival with PBSC may be decreased in ALL patients. In conclusion, the source of transplant cells needs to be evaluated by disease, especially when dealing with unrelated donors.

Outcome of 5651 hematopoietic stem cell transplants for hematological malignancies carried out in Europe in 1993: a reliability study of the registry

Outcome results of observational databases are frequently criticized as relying on incomplete information from incomplete patient populations. Few data are available to dispute these arguments of selection bias. The European Group for Blood and Marrow transplantation (EBMT) decided to address this question by evaluating the hematopoietic stem cell transplants performed in 1993. A comprehensive survey was launched in an effort to collect informations on all transplants for hematological malignancies performed throughout Europe during the year 1993. The main goals of this effort were to compare the group of spontaneously reported patients with the group of retrospectively solicited patients, and to give an accurate estimate of the outcome of all patients. For the year 1993, the annual EBMT activity survey indicated 6336 transplants performed for hematological malignancies in Europe. A total of 5651 transplants could be analyzed; 2595 were reported spontaneously by the teams (group A) and 3056 were retrieved on solicitation (group B). Patients and transplant characteristics for group A and B were very similar for most parameters with a few exceptions. There was no statistical difference for outcome at 3 years between groups A and B: disease-free survival (DFS) was 45 +/- 1% and 44 +/- 1%, relapse incidence (RI) 41 +/- 1% and 42 +/- 1%, transplant-related mortality (TRM) 23 +/- 1% and 23 +/- 1%, and overall survival (OS) 54 +/- 1% and 55 +/- 1%, respectively, for group A and group B. The real outcome at 3 years for the 5651 patients (group A + group B) transplanted in 1993 was 44 +/- 1%, 41 +/- 1%, 23 +/- 1%, and 54 +/- 1%, for DFS, RI, TRM and OS, respectively. The outcome at 3 years by transplant modality, autologous or allogeneic transplants, and by disease categories showed no difference between groups A and B.

Autologous stem cell transplantation in acute lymphocytic leukemia

Autologous stem cell transplantation (ASCT) as well as allogeneic stem cell transplantation and conventional chemotherapy (CT) are less effective at treating acute lymphocytic leukemia (ALL) than acute myelocytic leukemia (AML). Chemoresistance and late relapses are hallmarks of ALL. In this context, the question of whether ASCT is superior to CT remains unanswered. In vitro marrow purging using monoclonal antibodies is not routinely used. This review summarizes the results of ASCT for adult and childhood ALL. Statistics from the European Group for Blood and Marrow Transplantation reveal a transplant-related mortality at 5 years of 11% +/- 1%, a relapse incidence of 60% +/- 2%, and a leukemia-free survival (LFS) and overall survival (OS) of 36% +/- 2% and 42% +/- 2%, respectively in 1,366 adults autografted in first remission (CR1). In 269 children, the LFS and OS were 50% +/- 3% and 54% +/- 3%, respectively. There was no evidence in favor of purging the autograft in vitro. In contrast, multicentric and single-institution studies have found better results in adults autografted in CR1, with LFS at 5 years from 46% to 64%, possible efficacy of marrow in vitro purging with mafosfamide (LFS 52%), and improvement in outcome with additional measures post-ASCT, such as maintenance chemotherapy (LFS 57%). Further, as already observed for AML, analyses by risk groups suggest that ASCT may essentially benefit good- but not poor-risk patients. For patients with the Ph1/bcr-abl translocation, the role of STI571 anti-tyrosine kinase for in vivo purging before stem cell harvesting is being investigated.

In vitro production of dendritic cells from human blood monocytes for therapeutic use

Dendritic cells (DC) are professional antigen-presenting cells that are promising adjuvants for clinical immunotherapy. Methods to generate in vitro large numbers of functional human DC using either peripheral blood monocytes or CD34(+) pluripotent hematopoietic progenitor cells have been now developed. For this purpose, their in vitro production for further clinical use need to fit good manufacturing practice (GMP) conditions. In the present review, we give our experience of such a procedure: it includes collection of mononuclear cells by apheresis, separation of monocytes by elutriation, and culture of monocytes with GM-CSF + IL-13 + human serum (autologous patient's serum or AB serum) or in a serum-free medium (AIM V). The characteristics of monocyte-derived DC grown in these various conditions varied mainly regarding their phenotype and their morphology in confocal microscopy, whereas no significant differences were found in their capacity to phagocytize latex particles and to stimulate allogeneic (MLR) or autologous lymphocytes (antigen-presentation tests). The DC were also cryopreserved in bags (either by putting the bags directly in a -80 degrees C mechanical freezer or using a classical liquid nitrogen controlled-rate freezer at -1 degrees C/min) in a solution containing 10% dimethyl sulfoxide (Me(2)SO) and 2% human albumin in doses of DC available for several infusions. The mean recoveries after freezing and thawing were not statistically different (around 70%). The immunophenotype of DC, as well as the T lymphocyte-stimulating capacity, were not modified by the freezing--thawing procedure. The results obtained demonstrate that the experimental conditions we set up are easily applicable in clinical trials and lead to large numbers of well-defined DC. Clinical trials using DC already published will be discussed.

Level of Flt3-ligand in plasma: a possible new bio-indicator for radiation-induced aplasia

PURPOSE

To follow plasma Flt3-ligand (FL) concentrations in irradiated animals in order to evaluate it as an indicator of bone marrow damage for the management of accidental radiation-induced aplasia.

MATERIALS AND METHODS

Non-human primates were irradiated at doses ranging from 2 to 8 Gy, using whole- or partial-body irradiation. Plasma FL concentrations and blood cell counts were determined daily.

RESULTS

FL concentrations increased as early as day 2 after irradiation, whatever the irradiation dose. Increase in plasma FL concentration on day 5 post-irradiation was correlated with radiation dose and with the severity of radiation-induced aplasia. During the course of aplasia, FL concentrations in plasma were inversely correlated with neutrophil counts. A peak in FL concentration appeared before the neutrophil nadir, and the subsequent decrease in FL concentration was correlated with the recovery of blood-cell populations.

CONCLUSIONS

Monitoring plasma FL concentration can be used as an indicator of radiation-induced marrow aplasia, and this may be of use in accidental irradiation situations.

Improved efficiency of remission induction facilitates autologous BMT harvesting and improves overall survival in adults with AML: 108 patients treated at a single institution

A hundred and eight patients less than 60 years old with de novo acute myeloid leukemia were treated between 1982 and 1994 by protocols including final intensification with a transplant using autologous bone marrow purged by mafosfamide in first remission in the absence of an HLA-matched sibling donor available for allograft. From 1989, we attempted to improve tumor control by using high-dose anthracyclines in induction, by increasing from one to two the number of consolidation courses pre-transplant and by introducing intermediate doses of cytarabine in the first consolidation course. The CR rate was 77% (33/43) before 1989 and 90% (59/65) after 1989 (P = 0.06). Forty-five out of the 59 patients (76%) who achieved CR after 1989 could undergo bone marrow grafting in CR1 vs 16/33 (48%) before 1989 (P = 0.01). In spite of the higher proportion of patients above 50 years after 1989 (32%) toxicity was mild and an adequate graft was obtained more frequently after one collection. The principal factor relating to improvement in graft feasibility was the post-1989 modification of induction and consolidation regimens. This improvement in graft feasibility was associated with a better disease-free survival (DFS) (48 +/- 7% vs 32 +/- 8%, P = 0.04) and overall survival (OS) (53 +/- 6% vs 30 +/- 7%, P = 0.007) at 5 years. By multivariate analysis four factors were associated with overall survival (OS): karyotype, white blood cell count at diagnosis, treatment regimen and bone marrow grafting in CR1. This global approach should be prospectively compared with intensive chemotherapy.