A modified EBMT risk score predicts the outcome of patients with acute myeloid leukemia receiving allogeneic stem cell transplants

How to improve the outcomes of elderly acute myeloid leukemia patients through allogeneic hematopoietic stem cell transplantation

In recent years, with the gradual advancement of haploidentical transplantation technology, the availability of donors has increased significantly, along with the widespread use of reduced-intensity conditioning and the improvement of nursing techniques, giving more elderly acute myeloid leukemia (AML) patients the chance to receive allogeneic hematopoietic stem cell transplantation. We have summarized the classic and recently proposed pre-transplant assessment methods and assessed the various sources of donors, conditioning regimens, and post-transplant complication management based on the outcomes of large-scale clinical studies for elderly AML patients.

Patient age and donor HLA matching can stratify allogeneic hematopoietic cell transplantation patients into prognostic groups

BACKGROUND

Mixed results surround the accuracy of commonly used prognostic risk scores to predict overall survival (OS) and non-relapse mortality (NRM) in allogeneic hematopoietic stem cell transplant (allo-HCT) recipients. We hypothesize that a simple prognostic score performs better than conventional scoring systems.

PATIENTS AND METHODS

OS risk factors, HCT-CI, age-HCT-CI, and augmented-HCT-CI were studied in 299 patients who underwent allo-HCT for myeloid and lymphoid malignancies. A scoring system was developed based on results and validated in a different cohort of 455 patient.

RESULTS

2-year OS was 51% (95%CI 0.45-0.56). 2-year NRM was 34% (95%CI 0.29-0.39). HCT-CI and associated scores were grouped into 0-2 and ≥3. Age and HLA mismatch status were the only risk factors to affect OS in multivariate analysis (p = 0.02 and 0.05, respectively). HCT-CI and associated scores were not informative for OS prediction. The weighted scoring system assigned 0 to 2 points for age <50, 50 to 64, or ≥65, respectively, and 0 to 1 points for no HLA mismatch versus any mismatch (except HLA-DQ). Distinct 2-year OS [62%, 53%, and 38% (p = <0.001)] and NRM [24%, 34%, and 43% (p = 0.02)] groups were characterized. The scoring system was validated in a second independent cohort with similar results on OS and NRM (p <0.001).

CONCLUSIONS

A simple scoring system based on recipient's age and mismatch status accurately predicts OS and NRM in two distinct cohorts of allo-HCT patients. Its simplicity makes it a helpful tool to aid clinicians and patients in clinical decision making. This article is protected by copyright. All rights reserved.

Utility of the Treatment-Related Mortality (TRM) score to predict outcomes of adults with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation

There is long-standing interest in estimating non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) for AML, but existing tools have limited discriminative capacity. Using single-institution data from 861 adults with AML, we retrospectively examined the Treatment-Related Mortality (TRM) score, originally developed to predict early mortality following induction chemotherapy, as a predictor of post-HCT outcome. NRM risks increased stepwise across the four TRM score quartiles (at 3 years: 9% [95% confidence interval: 5-13%] in Q1 vs. 28% [22-34%] in Q4). The 3-year risk of relapse was lower in patients with lower TRM score (26% [20-32%] in Q1 vs. 37% [30-43%] in Q4). Consequently, relapse-free survival (RFS) and overall survival (OS) estimates progressively decreased (RFS at 3 years: 66% [59-72%] in Q1 vs. 36% [29-42%] in Q4; OS at 3 years: 72% [66-78%] in Q1 vs. 39% [33-46%] in Q4). With a C-statistic of 0.661 (continuous variable) or 0.642 (categorized by quartile), the TRM score predicted NRM better than the Pretransplantation Assessment of Mortality (PAM) score (0.603) or the HCT-CI/age composite score (0.576). While post-HCT outcome prediction remains challenging, these findings suggest that the TRM score may be useful for risk stratification for adults with AML undergoing allogeneic HCT.

Comparison of the Prognostic Ability of the HCT-CI, the Modified EBMT, and the EBMT-ADT Pre-transplant Risk Scores for Acute Leukemia

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) outcomes may be predicted by published risk scores; however, the ideal system has not been identified for acute leukemias.

PATIENTS AND METHODS

We retrospectively examined the Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI), modified European Group for Blood and Marrow Transplantation (mEBMT), EBMT-Alternating Decision Tree (ADT), and others on 231 patients with acute leukemia.

RESULTS

Acute myeloid leukemia was diagnosed in 200 patients, and acute lymphocytic leukemia was diagnosed in 31 patients. For HCT-CI, patients were grouped as 0 to 1, 2 to 3, and > 3. For mEBMT, patients were grouped as 0 to 2, 3, and > 3. For EBMT-ADT, the 100-day mortality was calculated and grouped as ≤ 4.1%, 4.1% to 11.5%, and > 11.5%. Higher HCI-CI demonstrated inferior overall survival (P = .04; c-statistic, 0.57), whereas mEBMT and EBMT-ADT did not stratify well. A new weighted score was developed that assigned 1 point for age ≥ 60 years, acute lymphocytic leukemia diagnosis, mismatch unrelated or haploidentical donor, cardiovascular comorbidity, and pre-transplant diabetes, whereas arrhythmia received 2 points. The new weighted score assigned 0 points to 88 (38%), 1 to 2 points to 121 (52%) and ≥ 3 points to 22 (10%) patients, and demonstrated improved prognostic capability compared with the other scores (P = .0001; c-statistic, 0.61).

CONCLUSIONS

The HCT-CI stratifies patients with leukemia for overall survival but is inferior to our single-center score, which is influenced by cardiac comorbidity and arrhythmia. Differences in pre-transplant risk scores may be related to different transplant practices.

Predominant low Hematopoietic Cell Transplantation Specific Comorbidity Index (HCT-CI) score in a Mexican referral center: a selection bias caused by limited-resources?

INTRODUCTION

To date, many studies have validated the Hematopoietic Cell Transplantation Specific Comorbidity Index (HCT-CI) scoring system in allogeneic hematopoietic stem cell transplantation (allo-HSCT), but studies from developing countries remain scarce.

OBJECTIVE

The aim of this study was to evaluate and categorize Mexican patients using the HCT-CI at a referral center.

METHODS

One hundred and nineteen consecutive patients undergoing allo-HSCT at the National Institute of Medical Sciences and Nutrition in Mexico City were included. Patients were classified according to the HCT-CI scores.

RESULTS

The median age was 31 years and most were males (56%). Most patients had hematological malignancies (73%) and a low HCT-CI score (72%). The non-relapse mortality and survival were predicted according to the score.

CONCLUSIONS

This is one of the few studies to evaluate the HCT-CI in adults with HLA-matched donors in a developing country and our findings suggest that the high percentage of patients with a low HCT-CI scores, contrary to international reports, could be explained by different comorbidities and demographics, but mainly due to stricter filters applied to HSCT candidates and consequently, a potential selection bias caused by limited resources.

Acute Myeloid Leukemia in Young Adults: Does Everyone Need a Transplant?

With the exception of the minority of patients with acute myelocytic leukemia who are considered potentially cured by chemotherapy, hematopoietic cell transplantation (HCT) has traditionally been the recommended approach for those patients achieving complete remission who meet the criteria for HCT and have an appropriate stem-cell donor. This decision has become more complex with the discovery of new risk factors, such as genomic abnormalities and minimal residual disease, especially in younger populations. Patients younger than age 60 years who are considered fit and who do not harbor poor prognostic features are felt still to have a high likelihood of cure without having to undergo HCT. Here, we discuss the role that these emerging risk factors play in the decision to undergo transplantation, but emphasize that this remains a decision made jointly by the patient, the treating hematologist, and the transplant physician.

Description of CD8+ Regulatory T Lymphocytes and Their Specific Intervention in Graft-versus-Host and Infectious Diseases, Autoimmunity, and Cancer

Gershon and Kondo described CD8⁺ Treg lymphocytes as the first ones with regulating activity due to their tolerance ability to foreign antigens and their capacity to inhibit the proliferation of other lymphocytes. Regardless, CD8⁺ Treg lymphocytes have not been fully described-unlike CD4⁺ Treg lymphocytes-because of their low numbers in blood and the lack of specific and accurate population markers. Still, these lymphocytes have been studied for the past 30 years, even after finding difficulties during investigations. As a result, studies have identified markers that define their subpopulations. This review is focused on the expression of cell membrane markers as CD25, CD122, CD103, CTLA-4, CD39, CD73, LAG-3, and FasL as well as soluble molecules such as FoxP3, IFN-γ, IL-10, TGF-β, IL-34, and IL-35, in addition to the lack of expression of cell activation markers such as CD28, CD127 CD45RC, and CD49d. This work also underlines the importance of identifying some of these markers in infections with several pathogens, autoimmunity, cancer, and graft-versus-host disease as a strategy in their prevention, monitoring, and cure.

Hematopoietic cell transplantation comorbidity index and risk of developing invasive fungal infections after allografting

We evaluated the potential correlation of the hematopoietic cell transplantation comorbidity index (HCT-CI) with the risk of developing post-transplant invasive fungal infections (IFIs). Between January 2009 and March 2015, 312 consecutive patients who received a first allograft entered the study. Low/intermediate HCT-CI risk score (0-2) was observed in 172/312 (55%), whereas high HCT-CI score (≥3) was seen in 140/312 (45%). Overall, 51/312 (16%) patients experienced IFI, defined as possible in 19 (6%), probable in 27 (9%), and proven in 5 (2%). Cumulative incidence of probable-proven IFI at 1 year was 8.5% with a significant higher incidence in patients with high HCT-CI (12%) vs. those with low-intermediate HCT-CI (5%; p = 0.006). There was a strong trend for a higher incidence of baseline severe pulmonary comorbidity in patients who developed probable-proven IFI (p = 0.051). One-year cumulative incidence of non-relapse mortality was higher in patients with IFI vs. those without, 49 and 16% (p < 0.001). By multivariate analysis, disease status at transplant and high HCT-CI, when combined with acute GVHD, were independently associated with the risk of post-transplant IFI. This study shows that a high HCT-CI predicts the risk of developing IFI and may indicate the need of mold-active antifungal prophylaxis in high-risk patients.

Minimal residual disease by either flow cytometry or cytogenetics prior to an allogeneic hematopoietic stem cell transplant is associated with poor outcome in acute myeloid leukemia

Relapsed acute myeloid leukemia (AML) is a significant challenge after allogeneic hematopoietic cell transplant (HCT). Multiparameter flow cytometry (MFC), conventional cytogenetics (CG), and fluorescence in situ hybridization (FISH) are routinely performed on bone marrow specimens prior to HCT to assess disease status. We questioned the extent by which pre-HCT evidence of minimal residual disease (MRD) detected by these standard assays, corresponded with post-HCT relapse. We conducted a single center, retrospective study of 166 AML patients who underwent HCT. Thirty-eight of one hundred sixty-six (23%) patients in complete remission (CR) or CR with incomplete count recovery (CRi) had MRD detectable by MFC, CG, or FISH. MRD was more frequently seen in patients with poor risk karyotype at diagnosis (P = 0.011). MRD-negative patients (MRD^neg) had significantly longer overall survival (OS) and relapse-free survival than patients who were MRD positive (MRD^pos) (P = 0.002 and 0.013, respectively). In patients with MRD^pos prior to HCT, the presence of acute graft vs. host disease (GVHD) (grade ≥ 2) or chronic GVHD significantly improved progression free survival (PFS) (hazard ratio (HR) = 0.053 (95% confidence interval (CI): 0.01-0.279), P = 0.0005) and OS (HR = 0.211 (95% CI: 0.081-0.547), P = 0.0014).

European Group for Blood and Marrow Transplantation Risk Score Predicts the Outcome of Patients with Acute Leukemia Receiving Single Umbilical Cord Blood Transplantation

The European Group for Blood and Marrow Transplantation (EBMT) risk score has been implemented as an important tool to predict patient outcomes after allogeneic hematopoietic stem cell transplantation. However, to our knowledge, this score has never been applied in cases of single umbilical cord blood transplantation (sUCBT). We retrospectively analyzed 207 consecutive patients with acute leukemia who received sUCBT at our center between February 2011 and December 2015. The probabilities of 3-year overall survival (OS) and leukemia-free survival (LFS) of the entire cohort were 65.0% and 59.8%, respectively, whereas the cumulative incidences of 3-year nonrelapse mortality (NRM) and relapse rate were 19.5% and 20.3%, respectively. In the univariate analysis, a higher EBMT risk score was associated with worse OS and LFS and higher NRM and relapse rate, ranging from 81.7%, 75.9%, 7.3%, and 15.3%, respectively, for patients with a score of 1 to 43.8%, 44.3%, 31.7%, and 23.9%, respectively, for patients with scores of 4 to 6. Hazard ratios of OS, LFS, and NRM all steadily increased for each additional score point. Importantly, the prognostic value of the EBMT risk score on OS, LFS, NRM, and relapse was maintained in the multivariate analysis. Moreover, considering the univariate analysis results of donor-recipient gender and mismatched allele-level HLA-A, -B, -C, and -DRB1 loci on patient outcomes and the fairly strong interaction between time from diagnosis to sUCBT and disease status, we developed a modified sUCBT-EBMT risk score by using degrees of 8-allele HLA match instead of donor type, donor-recipient gender combination, and time from diagnosis to sUCBT, and found that the modified score could also be used as a predictor for patient outcomes after sUCBT. The EBMT risk score is a good predictor of outcomes of patients with leukemia after sUCBT. The modified sUCBT-EBMT risk score can also be used as a pretransplant risk assessment, but this metric still requires further evaluation with a larger cohort.

Characteristics predicting outcomes of allogeneic stem-cell transplantation in relapsed acute myelogenous leukemia

BACKGROUND

Allogeneic hematopoietic stem-cell transplantation (ahsct) is associated with significant morbidity and mortality, but it can cure carefully selected patients with acute myeloid leukemia (aml) in second remission (cr2). In a cohort of patients with aml who underwent ahsct in cr2, we determined the pre-transplant factors that predicted for overall survival (os), relapse, and non-relapse mortality. We also sought to validate the prognostic risk groups derived by Michelis and colleagues in this independent population.

METHODS

In a retrospective chart review, we obtained data for 55 consecutive patients who underwent ahsct for aml in cr2. Hazard ratios were used to describe the independent effects of pre-transplant variables on outcome, and Kaplan-Meier curves were used to assess outcomes in the three prognostic groups identified by Michelis and colleagues.

RESULTS

At 1, 3, and 5 years post-transplant, os was 60%, 45.5%, and 37.5% respectively. Statistically significant differences in os, relapse mortality, and non-relapse mortality were not identified between the prognostic risk groups identified by Michelis and colleagues. Women were less likely than men to relapse, and a modified European Society for Blood and Marrow Transplantation (mebmt) score of 3 or less was associated with a lower non-relapse mortality.

CONCLUSIONS

The 37.5% 5-year os in this cohort suggests that, compared with other options, ahsct offers patients with aml in cr2 a better chance of cure. Our study supports the use of the mebmt score to predict non-relapse mortality in this population.

Predictive significance of the European LeukemiaNet classification of genetic aberrations in patients with acute myeloid leukaemia undergoing allogeneic stem cell transplantation

OBJECTIVES

The purpose of this study was to evaluate the predictive capacity of the European LeukemiaNet (ELN) classification of genetic risk in patients with acute myeloid leukaemia (AML) undergoing allogeneic stem cell transplantation (alloSCT).

METHODS

We retrospectively analysed 274 patients transplanted at our centre between 2004 and 2014.

RESULTS

The ELN grouping is comparable to the Southwest Oncology Group/Eastern Cooperative Oncology Group (SWOG/ECOG) stratification in predicting the outcome after alloSCT [overall P = 0.0064 for disease-free survival (DFS), overall P = 0.003 for relapse]. Patients with an intermediate-1 profile have a significantly elevated 5-yr relapse incidence as compared to favourable risk patients, that is 40% vs. 15%, [hazard ratio (HR) 2.58, P = 0.048]. An intermediate-1 risk profile is an independent predictor for relapse as determined by multivariate Cox regression analysis (HR 3.05, P = 0.023). In intermediate-1 patients, the presence of an FLT3 internal tandem duplication (FLT3-ITD) is associated with a significantly increased relapse incidence (P = 0.0323), and a lower DFS (P = 0.0465). FLT3-ITD is an independent predictor for overall survival, DFS and relapse incidence in the intermediate-1 subgroup.

CONCLUSIONS

The ELN stratification of genetic risk predicts the outcome of patients with AML undergoing alloSCT. Patients with an intermediate-1 profile have a high risk for treatment failure due to relapse, which prompts the development of alternative treatment strategies.

Combined model of the EBMT score modified model and the HCT-CI improves the stratification of high-risk patients undergoing unmanipulated haploidentical blood and marrow transplantation

Both European Group for blood and marrow transplantation risk score (EBMT score modified model) and hematopoietic cell transplantation comorbidity index (HCT-CI) are suitable for evaluating patients undergoing unmanipulated haploidentical blood and marrow transplantation (HBMT), while the predictive capacity of the combined model following haploidentical transplantation is still unknown. In this study, we calculated and validated 322 consecutive unmanipulated HBMT patients. Patients in groups with HCT-CI scores of 0 or 1-2 exhibited similar overall survival (OS), non-relapse mortality (NRM), and relapse rates, independent of their EBMT score modified model. In the group in which patients' HCT-CI scores were ≥3, patients with high EBMT score modified model showed lower OS (p = 0.003) and higher NRM (p = 0.001) than did patients with low EBMT score. In conclusion, this combined model can be used to predict outcomes and may improve the stratification of high-risk patients following unmanipulated HBMT.

Patient age, remission status and HCT-CI in a combined score are prognostic for patients with AML undergoing allogeneic hematopoietic cell transplantation in CR1 and CR2

For AML, older age, advanced disease and increased hematopoietic cell transplant comorbidity index (HCT-CI) are associated with worse prognosis following allogeneic hematopoietic cell transplantation (HCT). This single-center retrospective study investigated the influence of pre-transplant characteristics on outcomes of 387 patients undergoing allogeneic HCT for AML in CR1 and CR2. The multivariable analysis model for overall survival (OS) included age (hazard ratio (HR)=2.24 for ages 31-64 years and HR=3.23 for age ⩾65 years compared with age ⩽30 years, P=0.003), remission status (HR=1.49 for CR2 compared with CR1, P=0.005) and HCT-CI score (HR=1.47 for ⩾3 compared with <3, P=0.005). Transplant year was significantly associated with OS (P=0.001) but this did not influence the model. A weighted score was developed with age ⩽30, CR1 and HCT-CI score <3 receiving 0 points each, and CR2 and HCT-CI score ⩾3 receiving 1 point each. Ages 31-64 received 2 points, age ⩾65 received 3 points. Scores were grouped as follows: scores 0-1 (low risk, n=36), score 2 (intermediate-low risk, n=147), score 3 (intermediate-high risk, n=141) and scores 4-5 (high risk, n=63) with 3-year OS of 71%, 55%, 42% and 29% for scores 0-1, 2, 3 and 4-5, respectively (P<0.0001). The score predicted nonrelapse mortality (P=0.03) but not cumulative incidence of relapse (P=0.18). This model should be validated for the pre-HCT assessment of AML patients in CR1 and CR2.

Allogeneic stem cell transplantation for refractory acute myeloid leukemia: a single center analysis of long-term outcome

For patients with refractory acute myeloid leukemia (AML), allogeneic stem cell transplantation (alloSCT) represents the only curative approach. We here analyzed the long-term outcome of 131 consecutive patients with active AML, which was either primary refractory or unresponsive to salvage chemotherapy, transplanted at our center between 1997 and 2013. After a median follow-up of 48 months for the surviving patients, disease-free survival (DFS) at 5 yr post alloSCT was 26% (94% CI: 17-35). Relapses, most of which occurred within the first 2 yr from transplant, were the predominant cause of treatment failure affecting 48% (95%CI: 40-58) of patients, whereas non-relapse mortality was 26% (95%CI: 20-36) at 5 yr and thereafter. A marrow blast count ≥20% before alloSCT was an independent prognosticator associated with an inferior DFS (HR: 1.58, P = 0.027), whereas the development of chronic graft-versus-host disease (cGvHD) predicted an improved DFS (HR 0.21, P < 0.001) and a decreased relapse incidence (HR: 0.18, P = 0.026), respectively. These results indicate that alloSCT represents a curative treatment option in a substantial proportion of patients with refractory AML. A pretransplant blast count <20% before alloSCT and the development of cGvHD are the most important predictors of long-term disease control.

Impact of early remission by induction therapy on allogeneic stem cell transplantation for acute myeloid leukemia with an intermediate-risk karyotype in first complete remission

For patients with acute myeloid leukemia (AML) early achievement of remission during induction treatment is an important predictor for long-term outcome irrespective of the type of consolidation therapy employed. Here, we retrospectively examined the prognostic impact of early remission (ER) vs. delayed remission (DR) in a cohort of 132 AML patients with an intermediate-risk karyotype undergoing allogeneic stem cell transplantation (alloSCT) in first complete remission (CR1). In contrast to patients showing DR, patients achieving ER had a significantly higher 3-yr overall survival (OS) and disease-free survival (DFS) of 76% vs. 54% (P = 0.03) and 76% vs. 53% (P = 0.03). Likewise, 3 yr after alloSCT the cumulative incidence of relapse (CI-R) was significantly lower in the ER subgroup as compared to patients achieving DR, that is, 10% vs. 35% (P = 0.004), whereas non-relapse mortality (NRM) did not differ significantly. Multivariate analysis identified DR as an independent prognosticator for an inferior DFS (HR 3.37, P = 0.002) and a higher CI-R (HR 3.55, P = 0.002). Taken together, these data may indicate that the rapid achievement of remission predicts a favorable outcome in patients with intermediate-risk AML undergoing alloSCT in CR1. In turn, the adverse effect of DR may not be fully overcome by alloSCT.

EBMT risk score can predict the outcome of leukaemia after unmanipulated haploidentical blood and marrow transplantation

Systematic, standardised pretransplant risk assessment is an important tool for predicting patient outcomes following allogeneic haematopoietic SCT (HSCT). To assess the European Group for Blood and Marrow Transplantation (EBMT) risk score capacities for predicting patient outcomes following unmanipulated haploidentical blood and marrow transplantation (HBMT), we analysed 502 leukaemia patients who received transplants at our centre between 2008 and 2010. The cohort OS and leukaemia-free survival (LFS) were 72.1% and 68.1%, whereas the cumulative non-relapse mortality (NRM) and relapse incidences were 16.5% and 16.1%. According to univariate analysis, the values for OS, LFS and NRM were worse for an EBMT risk score of 6 (40.0, 40.0, 50.0%) than a score of 1 (83.1, 78.3, 8.4%). Hazard ratios steadily increased for each additional score point. Likewise, a higher EBMT risk score was associated with an increased relapse incidence. Importantly, the EBMT risk score prognostic value regarding OS, LFS, NRM and relapse was maintained in the multivariate analysis. Moreover, we also made a haploidentical EBMT (haplo-EBMT) risk score, which used number of HLA disparity instead of donor type, and the haplo-EBMT risk scores can also be used to predict patient outcomes following unmanipulated HBMT.

Validation of the EBMT Risk Score for South Brazilian Patients Submitted to Allogeneic Hematopoietic Stem Cell Transplantation

Background. Allogeneic hematopoietic stem cell transplantation (HSCT) is still associated with a high transplant-related mortality rate. In 2009, the EBMT risk score was validated as a simple tool to predict the outcome after allogeneic HSCT for acquired hematological disorders. Objectives. The aim of this study was to validate the applicability of the EBMT risk score for allogeneic HSCT on South Brazilian patients. Methods. A retrospective observational study was performed based on patients' records and data base at Hospital de Clínicas de Porto Alegre, including all allogeneic transplants for malignant and severe aplastic anemia from 1994 to 2010. Patients were categorized according to EBMT risk score and overall survival (OS). Nonrelapse mortality (NRM) and relapse rate (RR) were analyzed. Results. There were 278 evaluable patients. OS, NRM, and RR at five years median followup were 48.7%, 40.7%, and 30.7%, respectively. The OS was 81.8% for risk score 0 and 0% for score 6 (P < 0.001), and NRM was 13.6% and 80% for risk scores 0 and 6, respectively (P = 0.001). Conclusion. The EBMT risk score can be utilized as a tool for clinical decision making before allogeneic HSCT for malignant hematological diseases and severe aplastic anemia at a single center in Brazil.

Cytogenetic risk grouping by the monosomal karyotype classification is superior in predicting the outcome of acute myeloid leukemia undergoing allogeneic stem cell transplantation in complete remission

We retrospectively analyzed the impact of cytogenetic abnormalities grouped according to the monosomal karyotype (MK) classification or the Southwest Oncology/Eastern Cooperative Oncology Group (SWOG/ECOG) definition in 263 patients with acute myeloid leukemia (AML) who underwent allogeneic stem cell transplantation (alloSCT) in complete remission (CR) at our center. Risk grouping using the MK criteria shows a highly significant difference in 5-yr overall survival (OS) ranging between 67%, for the most favorable, and 32%, for the poorest risk group (P = 0.001). Although similarly precise in predicting OS, the MK scheme better separates patients with respect to relapse incidence as compared to the SWOG/ECOG grouping (P = 0.0001 vs. P = 0.01). Notably, patients displaying non-MK abnormalities (MK-) had a 5-yr relapse incidence identical to those cytogenetically normal (CN), that is 24%. Multivariate analysis revealed that the MK classification is an independent prognosticator and superior in predicting OS (hazard ratios, HR 3.74, P = 0.01) and relapse incidence (HR 3.74, P = 0.005) as compared to the SWOG/ECOG criteria. Finally, subgroup analysis revealed that the prognostic capacity of the MK classification is highly significant in patients treated with standard myeloablative conditioning prior to alloSCT (P = 0.0011 for OS, P = 0.0007 for relapse). In contrast, the MK grouping failed to predict OS or relapse incidence in patients treated with reduced intensity conditioning. Taken together, these results indicate that the MK classification is superior in predicting the overall outcome of patients with AML undergoing alloSCT in CR. Furthermore, our data suggest that the genetic risk profile of MK- and CN patients is mostly overlapping in this setting.

Acute myeloid leukemia creates an arginase-dependent immunosuppressive microenvironment

Acute myeloid leukemia (AML) is the most common acute leukemia in adults and the second most common frequent leukemia of childhood. Patients may present with lymphopenia or pancytopenia at diagnosis. We investigated the mechanisms by which AML causes pancytopenia and suppresses patients' immune response. This study identified for the first time that AML blasts alter the immune microenvironment through enhanced arginine metabolism. Arginase II is expressed and released from AML blasts and is present at high concentrations in the plasma of patients with AML, resulting in suppression of T-cell proliferation. We extended these results by demonstrating an arginase-dependent ability of AML blasts to polarize surrounding monocytes into a suppressive M2-like phenotype in vitro and in engrafted nonobese diabetic-severe combined immunodeficiency mice. In addition, AML blasts can suppress the proliferation and differentiation of murine granulocyte-monocyte progenitors and human CD34(+) progenitors. Finally, the study showed that the immunosuppressive activity of AML blasts can be modulated through small-molecule inhibitors of arginase and inducible nitric oxide synthase, suggesting a novel therapeutic target in AML. The results strongly support the hypothesis that AML creates an immunosuppressive microenvironment that contributes to the pancytopenia observed at diagnosis.

Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia

We retrospectively analysed 78 patients with relapsed (n = 38), primary refractory (n = 34) or untreated (n = 6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47 %) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29 %). With a median follow-up time of 5 years, 13 of 78 patients (17 %) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58 %), infection in ten patients (16 %) and GVHD in six (9 %). One-year non-relapse mortality was 35 %. In multivariate analysis, performance status ≥80 % WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P = 0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.