Molecular Taxonomy of Myelodysplastic Syndromes and its Clinical Implications.

Myelodysplastic syndromes/neoplasms (MDS) are clonal hematologic disorders characterized by morphologic abnormalities of myeloid cells and peripheral cytopenias. While genetic abnormalities underlie the pathogenesis of these disorders and their heterogeneity, current classifications of MDS rely predominantly on morphology. We performed genomic profiling of 3,233 patients with MDS or related disorders to delineate molecular subtypes and define their clinical implications. Gene mutations, copy-number alterations (CNAs), and copy-neutral loss of heterozygosity (cnLOH) were derived from targeted sequencing of a 152-gene panel, with abnormalities identified in 91, 43, and 11% of patients, respectively. We characterized 16 molecular groups, encompassing 86% of patients, using information from 21 genes, 6 cytogenetic events, and LOH at the TP53 and TET2 loci. Two residual groups defined by negative findings (molecularly not-otherwise specified, absence of recurrent drivers) comprised 14% of patients. The groups varied in size from 0.5% to 14% of patients and were associated with distinct clinical phenotypes and outcomes. The median bone marrow blast percentage across groups ranged from 1.5 to 10%, and the median overall survival from 0.9 to 8.2 years. We validated 5 well-characterized entities, added further evidence to support 3 previously reported subsets, and described 8 novel groups. The prognostic influence of bone marrow blasts depended on the genetic subtypes. Within genetic subgroups, therapy-related MDS and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) had comparable clinical and outcome profiles to primary MDS. In conclusion, genetically-derived subgroups of MDS are clinically relevant and may inform future classification schemas and translational therapeutic research.

Molecular and clinical presentation of UBA1-mutated myelodysplastic syndromes.

Mutations in UBA1, which are disease-defining for VEXAS syndrome, have been reported in patients diagnosed with myelodysplastic syndromes (MDS). Here, we define the prevalence and clinical associations of UBA1 mutations in a representative cohort of patients with MDS. Digital droplet PCR profiling of a selected cohort of 375 male patients lacking MDS disease-defining mutations or established WHO disease classification identified 28 patients (7%) with UBA1 p.M41T/V/L mutations. Using targeted sequencing of UBA1 in a representative MDS cohort (n=2,027), we identified an additional 27 variants in 26 patients (1%), which we classified as likely/pathogenic (n=12) and unknown significance (n=15). Among the total 40 patients with likely/pathogenic variants (2%), all were male and 63% were classified by WHO2016 as MDS-MLD/SLD. Patients had a median of one additional myeloid gene mutation, often in TET2 (n=12), DNMT3A (n=10), ASXL1 (n=3), or SF3B1 (n=3). Retrospective clinical review where possible showed that 83% (28/34) UBA1-mutant cases had VEXAS-associated diagnoses or inflammatory clinical presentation. The prevalence of UBA1-mutations in MDS patients argues for systematic screening for UBA1 in the management of MDS.

Immune reconstitution after single-unit umbilical cord blood transplantation using anti-thymoglobulin and myeloablative conditioning in adults with hematological malignancies.

This study aimed to investigate the kinetics of immune recovery following umbilical cord blood transplantation (UCBT) in adults who received a myeloablative conditioning (MAC) regimen and antithymocyte globulin (ATG). While the immune recovery kinetics has been extensively studied in pediatric UCBT recipients, limited data exist for adults. We conducted a comprehensive analysis of 221 consecutive adult patients who underwent UCBT with MAC and ATG at a single institution. Our objective was to evaluate the influence of patient, disease, and transplant factors, along with acute graft-versus-host disease (aGVHD), on immune reconstitution and overall survival. Our findings confirm a delayed recovery of T cells, while B and NK cell reconstitution exhibited rapid progress, with NK cell counts reaching normal levels within 3 months post-transplantation and B cells within 6 months. Within CD3+ T cells, CD8+ T cells also experienced a delayed recovery (12 months), but to a lesser extent compared to CD4+ T cells (18 months). Delayed immune recovery of T-cell subsets was associated with the development of aGVHD grade II-IV, older age, CMV negativity, and a female donor. Patients with lymphoproliferative diseases showed slower NK cell recovery. Our study demonstrates that adult patients undergoing MAC with ATG and receiving a single unit UCBT for hematologic malignancies experienced rapid reconstitution of NK and B cells. However, T cell recovery, particularly CD4+ T cells, was significantly delayed. To enhance T cell recovery, it may be crucial to consider UCB units with higher cellularity and optimize ATG doses in conditioning.

STIMULUS-MDS2 design and rationale: a phase III trial with the anti-TIM-3 sabatolimab (MBG453) + azacitidine in higher risk MDS and CMML-2.

Patients with higher-risk myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) unfit for hematopoietic stem cell transplantation have poor outcomes. Novel therapies that provide durable benefit with favorable tolerability and clinically meaningful improvement in survival are needed. T-cell immunoglobulin domain and mucin domain-3 (TIM-3) is an immuno-myeloid regulator expressed on immune and leukemic stem cells in myeloid malignancies. Sabatolimab is a novel immunotherapy targeting TIM-3 with a potential dual mechanism of reactivating the immune system and directly targeting TIM-3+ leukemic blasts suppressing the growth of cancer cells. Here, we describe the aims and design of the phase III STIMULUS-MDS2 trial, which aims to demonstrate the potential for sabatolimab plus azacitidine to improve survival for patients with higher-risk MDS and CMML-2 (NCT04266301). Clinical Trial Registration: NCT04266301 (ClinicalTrials.gov).

The ABNL-MARRO 001 study: a phase 1-2 study of randomly allocated active myeloid target compound combinations in MDS/MPN overlap syndromes.

BACKGROUND: Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) comprise several rare hematologic malignancies with shared concomitant dysplastic and proliferative clinicopathologic features of bone marrow failure and propensity of acute leukemic transformation, and have significant impact on patient quality of life. The only approved disease-modifying therapies for any of the MDS/MPN are DNA methyltransferase inhibitors (DNMTi) for patients with dysplastic CMML, and still, outcomes are generally poor, making this an important area of unmet clinical need. Due to both the rarity and the heterogeneous nature of MDS/MPN, they have been challenging to study in dedicated prospective studies. Thus, refining first-line treatment strategies has been difficult, and optimal salvage treatments following DNMTi failure have also not been rigorously studied. ABNL-MARRO (A Basket study of Novel therapy for untreated MDS/MPN and Relapsed/Refractory Overlap Syndromes) is an international cooperation that leverages the expertise of the MDS/MPN International Working Group (IWG) and provides the framework for collaborative studies to advance treatment of MDS/MPN and to explore clinical and pathologic markers of disease severity, prognosis, and treatment response. METHODS: ABNL MARRO 001 (AM-001) is an open label, randomly allocated phase 1/2 study that will test novel treatment combinations in MDS/MPNs, beginning with the novel targeted agent itacitinib, a selective JAK1 inhibitor, combined with ASTX727, a fixed dose oral combination of the DNMTi decitabine and the cytidine deaminase inhibitor cedazuridine to improve decitabine bioavailability. DISCUSSION: Beyond the primary objectives of the study to evaluate the safety and efficacy of novel treatment combinations in MDS/MPN, the study will (i) Establish the ABNL MARRO infrastructure for future prospective studies, (ii) Forge innovative scientific research that will improve our understanding of pathogenetic mechanisms of disease, and (iii) Inform the clinical application of diagnostic criteria, risk stratification and prognostication tools, as well as response assessments in this heterogeneous patient population. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov on August 19, 2019 (Registration No. NCT04061421).

Prospective Randomized Study Comparing Myeloablative Unrelated Umbilical Cord Blood Transplantation versus HLA-Haploidentical Related Stem Cell Transplantation for Adults with Hematologic Malignancies.

In this prospective randomized study, we compared the outcomes of single-unit umbilical cord blood transplantation (UCBT) and unmanipulated haploidentical stem cell transplantation (haplo-SCT) with post-transplantation cyclophosphamide (PTCy) in adults with hematologic malignancies. All patients received a myeloablative conditioning (MAC) regimen consisting of thiotepa, busulfan, and fludarabine, with antithymocyte globulin (ATG) added for UCBT recipients. Nineteen patients were randomized to UCBT and the other 26 to haplo-HSCT. Four patients (15%) allocated to the haplo-HSCT arm lacked a suitable donor and were crossed over to the UCBT arm. Finally, 23 underwent UCBT and 22 underwent haplo-HSCT. The cumulative incidence of neutrophil recovery was 87% at a median of 19 days (range, 13 to 24 days) in the UCBT arm versus 100% at a median of 17 days (range, 13 to 25 days) in the haplo-SCT arm (P = .04). Platelet recovery was 70% at a median of 40 days (range, 18 to 129 days) in the UCBT arm versus 86% at a median of 24 days (range, 12 to 127 days) in the haplo-HCT arm (P = .02). Rates of acute graft-versus-host disease (GVHD) grade II-IV or grade III-IV, overall chronic GVHD, and extensive chronic GVHD in the UCBT and Haplo-SCT arms were 43% versus 36% (P = .8), 9% versus 9% (P = 1), 66% versus 43% (P = .04), and 41% versus 23% (P = .2), respectively. Two-year nonrelapse mortality and relapse in the 2 arms were 52% versus 23% (P = .06) and 17% versus 23% (P = .5), respectively. Two-year disease-free survival, overall survival, and GVHD/relapse-free survival in the 2 arms were 30% versus 54% (P = .2), 35% versus 59% (P = .1), and 17% versus 40% (P = .04), respectively. Our data show that in the context of an MAC regimen, haplo-SCT with PTCy provides improved outcomes compared with ATG-containing single-unit UCBT.

Partial T Cell-Depleted Peripheral Blood Stem Cell Transplantation from HLA-Identical Sibling Donors for Patients with Severe Aplastic Anemia.

We analyzed the outcomes of 26 consecutive patients with acquired severe aplastic anemia (SAA) undergoing peripheral blood stem cell transplantation (PBSCT) with partial ex vivo T cell depletion with a targeted T cell dose from HLA-identical sibling donors. The median patient age was 37 years (range, 3 to 63 years). Four patients with uncontrolled pneumonia at the time of transplantation died, on days +1, +2, +21, and +26. All evaluable patients engrafted, with a median time to neutrophil recovery of 11 days (range, 10 to 14 days) and a median time to platelet recovery of 19 days (range, 8 to 53 days). Two patients had transient grade I acute graft-versus-host disease (GVHD) with skin involvement, but no patients developed grade II-IV acute GVHD. Two patients had mild skin chronic GVHD, and 1 patient had moderate chronic GVHD with ocular involvement. No relapse was observed after a median follow-up of 114 months (range, 4 to 233 months). The overall cumulative incidence of TRM at 10 years was 19%, whereas it was 5% for those with a Karnofsky Performance Status (KPS) score >60 at the time of transplantation. Disease-free survival, overall survival, and GVHD and relapse-free survival at 10 years were 81%, 81%, and 80%, respectively, for all patients and 95%, 95%, and 90%, respectively, for patients with a KPS score >60 at transplantation. Our data indicate that PBSCT with partial ex vivo T cell-depleted targeted cell dose grafts from an HLA-identical sibling donor is a feasible, safe, and effective approach to reduce GVHD and cure patients with SAA.

Development of a core outcome set for myelodysplastic syndromes - a Delphi study from the EUMDS Registry Group.

Treatment options for myelodysplastic syndromes (MDS) vary widely, depending on the natural disease course and patient-related factors. Comparison of treatment effectiveness is challenging as different endpoints have been included in clinical trials and outcome reporting. Our goal was to develop the first MDS core outcome set (MDS-COS) defining a minimum set of outcomes that should be reported in future clinical studies. We performed a comprehensive systematic literature review among MDS studies to extract patient- and/or clinically relevant outcomes. Clinical experts from the European LeukemiaNet MDS (EUMDS) identified 26 potential MDS core outcomes and participated in a three-round Delphi survey. After the first survey (56 experts), 15 outcomes met the inclusion criteria and one additional outcome was included. The second round (38 experts) resulted in six included outcomes. In the third round, a final check on plausibility and practicality of the six included outcomes and their definitions was performed. The final MDS-COS includes: health-related quality of life, treatment-related mortality, overall survival, performance status, safety, and haematological improvement. This newly developed MDS-COS represents the first minimum set of outcomes aiming to enhance comparability across future MDS studies and facilitate a better understanding of treatment effectiveness.

Incidence and outcome of invasive fungal disease after front-line intensive chemotherapy in patients with acute myeloid leukemia: impact of antifungal prophylaxis.

Few reports analyze the incidence and clinical outcome of invasive fungal disease (IFD) in patients with newly diagnosed acute myeloid leukemia (AML) undergoing intensive chemotherapy, and thus the impact of different antifungal prophylactic regimens remains unclear. We analyze the incidence and clinical outcome of IFD in a large series of adult AML patients undergoing front-line intensive induction and consolidation chemotherapy between 2004 and 2015 in a single institution. Three antifungal prophylaxis regimens were given (2004-2005 oral fluconazole, 2006-2012 intravenous itraconazole, and 2013-2015 voriconazole). Overall, 285 patients and 589 intensive chemotherapy episodes were assessed (47%) (induction courses 47% and consolidation 53%). The median age was 51 years (range, 17-65). We observed 56 (10%) episodes of IFD. According to the EORTC 2008 criteria, IFD was classified as possible (29, 52%), probable (17, 30%), and proven (10, 18%). Possible/probable/proven IFD rate was significantly lower during HiDAC consolidation as compared to any anthracycline-containing chemotherapy courses (2% vs. 11%, P = 0.001), and under voriconazole prophylaxis as compared to itraconazole and fluconazole (6% vs. 11% vs. 15%, P = 0.007), and the multivariate analysis showed that they were independent risk factors. Patients under voriconazole prophylaxis had shorter hospitalization duration and less frequent use of empirical or directed antifungal therapy. In conclusion, IFD was a frequent complication during upfront intensive chemotherapy courses for adult AML patients. This retrospective study shows that voriconazole prophylaxis was feasible and associated with a lower risk of IFD compared with intravenous itraconazole or oral fluconazole schedules.

Invasive fungal disease in patients undergoing umbilical cord blood transplantation after myeloablative conditioning regimen.

OBJECTIVE: Characteristics and risk factors (RFs) of invasive fungal disease (IFD) have been little studied in the setting of umbilical cord blood transplantation (UCBT). METHOD: We retrospectively included 205 single-unit myeloablative UCBT recipients with a median follow-up of 64 months. RESULTS: Fifty-six episodes of IFD were observed in 48 patients (23%) at a median time of 123 days after stem cell infusion. Invasive mold disease (IMD) occurred in 42 cases, 38 of them (90%) caused by invasive aspergillosis whereas invasive yeast disease (IYD) occurred in 14 cases, most of them due to candidemia (n = 12, 86%). The 5-year cumulative incidence of IFD, IMDs, and IYDs was 24% 19%, and 7%, respectively. In multivariate analysis, three RFs for IMDs were identified: age >30 years (HR 3.5, P = 0.017), acute grade II-IV graft-versus-host disease (HR 2.3, P = 0.011), and ≥1 previous transplant (HR 3.1, P = 0.012). The probability of IMDs was 2.5%, 14%, and 33% for recipients with none, 1, or 2-3 RFs, respectively (P < 0.001). Among IFD, IMDs had a negative effect on non-relapse mortality in multivariate analysis (HR 1.6, P = 0.039). IMDs showed a negative impact on overall survival (HR 1.59, P = 0.018). CONCLUSION: Invasive mold disease were very common and serious complication after UCBT.

Validation of a multivariable prediction model for post-engraftment invasive fungal disease in 465 adult allogeneic hematopoietic stem cell transplant recipients.

BACKGROUND: Recently, we reported a simple prognostic score for post-engraftment invasive fungal disease (IFD) obtained in 404 adult allogeneic hematopoietic stem cell transplant (alloSCT) (training cohort). OBJECTIVES: We aim to validate this score in an external cohort assessing the 1-year cumulative incidence (CI) of post-engraftment IFD. Additionally, we analyse the type of IFD and incidence of IFD according to type of prophylaxis. PATIENTS/METHODS: We included 465 consecutive adult recipients surviving >40 days who engrafted and were discharged without prior IFD (median age 45 years, range, 14-69). RESULTS: Patients classified as low-risk, 139; intermediate-risk, 162; and high-risk, 164 (35% vs 27% in the training cohort, P = 0.03). The CI of probable/proven IFD in the validation cohort was 8% vs 11% in the training cohort (P = 0.006). The only voriconazole prophylaxis used in the training cohort was 100 mg/12 h, 65% vs 27% in the validation cohort, but 38% received 200 mg/12 h. Thus, the validation cohort showed a lower CI of IFD (P = 0.009). The post-engraftment IFD score was validated, showing a CI of IFD for low-, intermediate- and high-risk of 3%, 6% and 14%, respectively (P < 0.001). CONCLUSION: To our knowledge, this is the first prognostic index to predict the occurrence of post-engraftment IFD after alloSCT that has been validated in an external cohort.

Current management of patients with chronic myelomonocytic leukemia.

PURPOSE OF REVIEW: The present review focuses on the current management of patients with chronic myelomonocytic leukemia (CMML) and the most recent developments in the field. RECENT FINDINGS: CMML is a heterogeneous malignant myeloid disorder sharing features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms and characterized by peripheral blood monocytosis and increased risk of progression to acute leukemia. Its natural course is highly variable and use of CMML-specific prognostic scoring systems is strongly recommended for tailoring treatment. Multiple recent studies have showed that somatic mutations, which are almost always present have a relevant and independent impact on survival but lack a clear role in predicting the response to currently available drugs. SUMMARY: The incorporation of somatic mutations to prognostic scoring systems has improved the prediction of patients' outcomes. Current treatment for CMML remains unsatisfactory. Allogeneic hematopoietic cell transplantation is the only curative option but is applicable to a minority of patients. Usually higher-risk patients displaying MDS-like characteristics are treated with hypomethylating agents (HMAs), whereas those with myeloproliferative features generally receive hydroxyurea or HMAs but none of these drugs substantially modify the natural history of CMML. Newer therapies are clearly needed.

Integrating clinical features and genetic lesions in the risk assessment of patients with chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm with variable clinical course. To predict the clinical outcome, we previously developed a CMML-specific prognostic scoring system (CPSS) based on clinical parameters and cytogenetics. In this work, we tested the hypothesis that accounting for gene mutations would further improve risk stratification of CMML patients. We therefore sequenced 38 genes to explore the role of somatic mutations in disease phenotype and clinical outcome. Overall, 199 of 214 (93%) CMML patients carried at least 1 somatic mutation. Stepwise linear regression models showed that these mutations accounted for 15% to 24% of variability of clinical phenotype. Based on multivariable Cox regression analyses, cytogenetic abnormalities and mutations in RUNX1, NRAS, SETBP1, and ASXL1 were independently associated with overall survival (OS). Using these parameters, we defined a genetic score that identified 4 categories with significantly different OS and cumulative incidence of leukemic evolution. In multivariable analyses, genetic score, red blood cell transfusion dependency, white blood cell count, and marrow blasts retained independent prognostic value. These parameters were included into a clinical/molecular CPSS (CPSS-Mol) model that identified 4 risk groups with markedly different median OS (from >144 to 18 months, hazard ratio [HR] = 2.69) and cumulative incidence of leukemic evolution (from 0% to 48% at 4 years, HR = 3.84) (P < .001). The CPSS-Mol fully retained its ability to risk stratify in an independent validation cohort of 260 CMML patients. In conclusion, integrating conventional parameters and gene mutations significantly improves risk stratification of CMML patients, providing a robust basis for clinical decision-making and a reliable tool for clinical trials.

Factors influencing platelet transfusion refractoriness in patients undergoing allogeneic hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation has been considered a risk factor for development of platelet transfusion refractoriness. The objective of this study was to assess the platelet transfusion refractoriness rate in patients undergoing allogeneic hematopoietic stem cell transplantation from different sources. We retrospectively reviewed the charts and transfusion records of patients who underwent allogeneic stem cell transplantation at our institution between 2013 and 2015. The evaluation of post-transfusion platelet count was assessed for each transfusion given, from day of progenitor infusion to day 30 after transplantation. Of 167 patients included in this study, 101 received peripheral blood stem cell transplantation (PBSCT) and 66 received umbilical cord blood transplantation (UCBT). Overall, the percentage of platelet transfusions with a 14-h CCI lower than 5000 was 59.3%, being these data significantly higher for UCBT (67.6%) than for PBSCT (31.0%). Seventy-eight percent of patients underwent UCBT become refractory, while 38.6% of patients who received PBSCT were refractory. Factors associated to platelet refractoriness were lower CD34+ cell dose infused, higher number of antibiotics used, presence of anti-HLA I antibodies, and reduced-intensity conditioning regimen. Platelet refractoriness is a frequent and complex adverse event and remains a therapeutic challenge in the management of patients undergoing HSCT. There is a higher rate of platelet refractoriness in patients who received UCBT as compared to patients who received PBSCT.

Enumerating bone marrow blasts from nonerythroid cellularity improves outcome prediction in myelodysplastic syndromes and permits a better definition of the intermediate risk category of the Revised International Prognostic Scoring System (IPSS-R).

The Revised International Prognostic Scoring System (IPSS-R) has been recognized as the score with the best outcome prediction capability in MDS, but this brought new concerns about the accurate prognostication of patients classified into the intermediate risk category. The correct enumeration of blasts is essential in prognostication of MDS. Recent data evidenced that considering blasts from nonerythroid cellularity (NECs) improves outcome prediction in the context of IPSS and WHO classification. We assessed the percentage of blasts from total nucleated cells (TNCs) and NECs in 3924 MDS patients from the GESMD, 498 of whom were MDS with erythroid predominance (MDS-E). We assessed if calculating IPSS-R by enumerating blasts from NECs improves prognostication of MDS. Twenty-four percent of patients classified into the intermediate category were reclassified into higher-risk categories and showed shorter overall survival (OS) and time to AML evolution than those who remained into the intermediate one. Likewise, a better distribution of patients was observed, since lower-risk patients showed longer survivals than previously whereas higher-risk ones maintained the outcome expected in this poor prognostic group (median OS < 20 months). Furthermore, our approach was particularly useful for detecting patients at risk of dying with AML. Regarding MDS-E, 51% patients classified into the intermediate category were reclassified into higher-risk ones and showed shorter OS and time to AML. In this subgroup of MDS, IPSS-R was capable of splitting our series in five groups with significant differences in OS only when blasts were assessed from NECs. In conclusion, our easy-applicable approach improves prognostic assessment of MDS patients.

Multidimensional assessment of patient condition and mutational analysis in peripheral blood, as tools to improve outcome prediction in myelodysplastic syndromes: A prospective study of the Spanish MDS group.

The International Prognostic Scoring System and its revised form (IPSS-R) are the most widely used indices for prognostic assessment of patients with myelodysplastic syndromes (MDS), but can only partially account for the observed variation in patient outcomes. This study aimed to evaluate the relative contribution of patient condition and mutational status in peripheral blood when added to the IPSS-R, for estimating overall survival and the risk of leukemic transformation in patients with MDS. A prospective cohort (2006-2015) of 200 consecutive patients with MDS were included in the study series and categorized according to the IPSS-R. Patients were further stratified according to patient condition (assessed using the multidimensional Lee index for older adults) and genetic mutations (peripheral blood samples screened using next-generation sequencing). The change in likelihood-ratio was tested in Cox models after adding individual covariates. The addition of the Lee index to the IPSS-R significantly improved prediction of overall survival [hazard ratio (HR) 3.02, 95% confidence interval (CI) 1.96-4.66, P < 0.001), and mutational analysis significantly improved prediction of leukemic evolution (HR 2.64, 1.56-4.46, P < 0.001). Non-leukemic death was strongly linked to patient condition (HR 2.71, 1.72-4.25, P < 0.001), but not to IPSS-R score (P = 0.35) or mutational status (P = 0.75). Adjustment for exposure to disease-modifying therapy, evaluated as a time-dependent covariate, had no effect on the proposed model's predictive ability. In conclusion, patient condition, assessed by the multidimensional Lee index and patient mutational status can improve the prediction of clinical outcomes of patients with MDS already stratified by IPSS-R.

Killer Cell Immunoglobulin-Like Receptor-Ligand Matching and Outcomes after Unrelated Cord Blood Transplantation in Acute Myeloid Leukemia.

The effect of killer cell immunoglobulin-like receptor (KIR)-ligand matching on outcomes after unrelated cord blood (CB) transplantation was studied in 461 patients with acute myeloid leukemia, categorizing KIR ligand for HLA-C groups C1 and C2 and Bw4. Donor-recipient HLA matching considered allele-level matching at HLA-A, -B, -C, and -DRB1. Separate analyses were conducted for 6-7/8 HLA-matched and 3-5/8 HLA-matched transplants because HLA matching confounded KIR-ligand matching (ie, KIR-ligand mismatching was less likely with better HLA matching). All patients received single CB unit and myeloablative conditioning. There were no significant differences in nonrelapse mortality (NRM), relapse, and overall mortality by KIR-ligand match status. However, among recipients of 3-5/8 HLA-matched transplants, NRM (HR, 2.26; P = .008) and overall mortality (HR, 1.78; P = .008) but not relapse were higher with KIR-ligand mismatched (host-versus-graft direction) compared with KIR-ligand matched transplants. These data do not support selecting CB units based on KIR-ligand match status for transplants mismatched at 1 or 2 HLA loci. Although transplants mismatched at 3 or more HLA loci are not recommended, avoiding KIR-ligand mismatching in this setting lowers mortality risks.

Erythroleukemia shares biological features and outcome with myelodysplastic syndromes with excess blasts: a rationale for its inclusion into future classifications of myelodysplastic syndromes.

Erythroleukemia was considered an acute myeloid leukemia in the 2008 World Health Organization (WHO) classification and is defined by the presence of ≥50% bone marrow erythroblasts, having <20% bone marrow blasts from total nucleated cells but ≥20% bone marrow myeloblasts from nonerythroid cells. Erythroleukemia shares clinicopathologic features with myelodysplastic syndromes, especially with erythroid-predominant myelodysplastic syndromes (≥50% bone marrow erythroblasts). The upcoming WHO revision proposes to eliminate the nonerythroid blast cell count rule and to move erythroleukemia patients into the appropriate myelodysplastic syndrome category on the basis of the absolute blast cell count. We conducted a retrospective study of patients with de novo erythroleukemia and compared their clinico-biological features and outcome with those of de novo myelodysplastic syndromes, focusing on erythroid-predominant myelodysplastic syndromes. Median overall survival of 405 erythroid-predominant myelodysplastic syndromes without excess blasts was significantly longer than that observed in 57 erythroid-predominant refractory anemias with excess blasts-1 and in 59 erythroleukemias, but no significant difference was observed between erythroid-predominant refractory anemias with excess blasts-1 and erythroleukemias. In this subset of patients with ≥50% bone marrow erythroblasts and excess blasts, the presence of a high-risk karyotype defined by the International Prognostic Scoring System or by the Revised International Prognostic Scoring System was the main prognostic factor. In the same way, the survival of 459 refractory anemias with excess blasts-2, independently of having ≥20% bone marrow blasts from nonerythroid cells or not, was almost identical to the observed in 59 erythroleukemias. Interestingly, 11 low-blast count erythroleukemias with 5 to <10% bone marrow blasts from total nucleated cells showed similar survival than the rest of erythroleukemias. Our data suggest that de novo erythroleukemia is in the spectrum of myelodysplastic syndromes with excess blasts and support its inclusion into future classifications of myelodysplastic syndromes.

Impact of allele-level HLA matching on outcomes after myeloablative single unit umbilical cord blood transplantation for hematologic malignancy.

We studied the effect of allele-level matching at human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 in 1568 single umbilical cord blood (UCB) transplantations for hematologic malignancy. The primary end point was nonrelapse mortality (NRM). Only 7% of units were allele matched at HLA-A, -B, -C, and -DRB1; 15% were mismatched at 1, 26% at 2, 30% at 3, 16% at 4, and 5% at 5 alleles. In a subset, allele-level HLA match was assigned using imputation; concordance between HLA-match assignment and outcome correlation was confirmed between the actual and imputed HLA-match groups. Compared with HLA-matched units, neutrophil recovery was lower with mismatches at 3, 4, or 5, but not 1 or 2 alleles. NRM was higher with units mismatched at 1, 2, 3, 4, or 5 alleles compared with HLA-matched units. The observed effects are independent of cell dose and patient age. These data support allele-level HLA matching in the selection of single UCB units.

Bloodstream infections in adult patients undergoing cord blood transplantation from unrelated donors after myeloablative conditioning regimen.

The incidence, epidemiology, and risk factors of bloodstream infection (BSI) and their impact on transplant outcomes after umbilical cord blood transplantation (UCBT) are not well defined. Between May 1997 and December 2012, 202 isolates in 189 episodes of BSI were registered in 134 of 241 patients who underwent single-unit myeloablative UCBT. Cumulative incidence (CI) of developing at least 1 episode of BSI was 21%, 29%, 34%, 42%, and 52% at days +7, +14, +30, +100, and +365, respectively. The median time of onset for the first BSI episode was day +10 (range, day -7 to +1217). Early BSI before day 7 was associated with increased nonrelapse mortality (relative risk [RR], 1.5; 95% confidence interval [CI], 1.1 to 2.3; P = .04), whereas BSI before day 14 was an independent adverse risk factor for neutrophil recovery (RR, .6; 95% CI, .5 to .9; P = .002). A higher CD8(+) cell dose of the graft was the only variable independently associated with reduced risk of BSI (RR, .1; 95% CI, .02 to .7; P = .02). The gram-negative rod (GNR) to gram-positive bacteria ratio was .9 before day +30 and 1.6 thereafter (P = .03). Escherichia coli (31%) and Pseudomonas sp. (28%) were the most frequently isolated among GNR. The overall crude mortality rate was 12% at day 7 and was higher for GNR (18%) compared with gram-positive bacteria (7%) (P = .03). These findings emphasize the importance of preventing bacterial infections during conditioning and the very early post-UCBT period.