Genomic classification and outcomes of young patients with polycythemia vera and essential thrombocythemia according to the presence of splanchnic vein thrombosis and its chronology.

To elucidate the role of splanchnic vein thrombosis (SVT) and genomic characteristics in prognosis and survival, we compared patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting SVT at diagnosis (n = 69, median age 43 years) or during follow-up (n = 21, median age 46 years) to a sex- and age-matched control group of PV/ET without SVT (n = 165, median age 48 years). The majority of patients presenting with SVT at diagnosis were classified as myeloproliferative neoplasm with heterozygous JAK2 mutation (87% of cases vs. 69% in PV/ET control group, p < 0.05), characterized by low JAK2 allele burden and no high-risk mutations. Despite this lower molecular complexity, patients presenting with SVT showed a higher risk of death (HR 3.0, 95% CI 1.5-6.0, p = 0.003) and lower event-free survival (HR 3.0, 95% CI 1.9-4.8, p < 0.001) than age- and sex-matched PV/ET controls. In patients presenting with SVT, molecular high-risk was associated with increased risk of venous re-thrombosis (HR 5.8, 95% CI 1.4-24.0, p = 0.01). Patients developing SVT during follow-up were more frequently allocated in molecular high-risk than those with SVT at diagnosis (52% versus 13%, p < 0.05). In the whole cohort of patients, molecular classification identified PV/ET patients at higher risk of disease progression whereas DNMT3A/TET2/ASXL1 mutations were associated with higher risk of arterial thrombosis. In conclusion, clinical and molecular characteristics are different in PV/ET patients with SVT, depending on whether it occurs at diagnosis or at follow-up. Molecular characterization by NGS is useful for assessing the risk of thrombosis and disease progression in young patients with PV/ET.

Endothelial Activation and Stress Index in adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide-based prophylaxis.

BACKGROUND AIMS: Post-transplant cyclophosphamide (PTCY)-based prophylaxis is becoming widespread for allogeneic hematopoietic cell transplantation (allo-HCT) performed independently of the selected donor source. In parallel, use of the Endothelial Activation and Stress Index (EASIX)-considered a surrogate parameter of endothelial activation-for predicting patient outcomes and clinical complications is gaining popularity in the allo-HCT setting. METHODS: We first investigated whether the dynamics of EASIX after allo-HCT differ between patients receiving PTCY and patients receiving other prophylaxis. We then investigated whether the predictive capacity of EASIX persists in PTCY-based allo-HCT. A total of 328 patients transplanted between 2014 and 2020 were included, and 201 (61.2%) received PTCY. RESULTS: EASIX trends differed significantly between the groups. Compared with patients receiving other prophylaxis, patients receiving PTCY had lower EASIX on day 0 and higher values between day 7 and day 100. In patients receiving PTCY, higher EASIX correlated significantly with higher non-relapse mortality (NRM) and lower overall survival (OS) when measured before and during the first 180 days after allo-HCT. In addition, higher EASIX scores measured at specific time points were predictors of veno-occlusive disease (VOD), transplant-associated thrombotic microangiopathy (TA-TMA) and grade 2-4 acute graft-versus-host disease (aGVHD) risk. CONCLUSIONS: This study demonstrates how EASIX trends vary during the first 180 days after allo-HCT in patients receiving PTCY and those not receiving PTCY and validates the utility of this index for predicting NRM, OS and risk of VOD, TA-TMA and grade 2-4 aGVHD in patients receiving PTCY.

Post-Transplantation Cyclophosphamide and Tacrolimus for Graft-versus-Host Disease Prevention after Allogeneic Hematopoietic Cell Transplantation from HLA-Matched Donors Has More Advantages Than Limitations.

This study compared the efficacy of graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy) and tacrolimus (Tac) versus other regimens in 272 adults undergoing peripheral blood (PB) allogeneic hematopoietic cell transplantation (allo-HCT) from HLA-matched donors. Of these 272 patients, 95 (34.9%) received PTCy/Tac. The times to neutrophil and platelet engraftment were longer in the PTCy/Tac group (20 days versus 16 days for neutrophils and 19 days versus 12 days for platelets). The day +30 cumulative incidence (CuI) of bacterial bloodstream infection was higher in the PTCy/Tac group (43.2% versus 13.0%; P < .001). The CuIs of grade II-IV and grade III-IV acute GVHD (aGVHD) at day +180 were 14.7% and 4.2%, and the CuI of moderate/severe cGVHD at 2 years was 2.4% in the PTCy/Tac group and 41.8% (hazard ratio [HR], .29; P < .001), 15.8%, (HR, .24; P = .007), and 47.0% (HR, .05; P < .001), respectively, in the no-PTCy group. The duration of immunosuppression was shorter in patients receiving PTCy/Tac (6.2 months versus 9.0 months; P < .001). PTCy/Tac patients had higher OS (2 years: 74.3% versus 60.9%; HR, .54; P = .012), lower NRM (2 years: 8.6% versus 15.8%; HR, .54; P = .11), comparable CuI of relapse (2 years: 26.0% versus 24.4%; HR, 1.03; P = .89), and higher GRFS (2 years: 59.1% versus 16.7%; HR, .32; P < .001). Using PTCy/Tac in HLA-matched PB allo-HCT improved transplantation outcomes at out institution compared with previous prophylactic regimens, including a higher probability of survival despite more delayed engraftment and a higher rate of bacterial infection.

Endothelial activation and damage as a common pathological substrate in different pathologies and cell therapy complications.

The endothelium is a biologically active interface with multiple functions, some of them common throughout the vascular tree, and others that depend on its anatomical location. Endothelial cells are continually exposed to cellular and humoral factors, and to all those elements (biological, chemical, or hemodynamic) that circulate in blood at a certain time. It can adapt to different stimuli but this capability may be lost if the stimuli are strong enough and/or persistent in time. If the endothelium loses its adaptability it may become dysfunctional, becoming a potential real danger to the host. Endothelial dysfunction is present in multiple clinical conditions, such as chronic kidney disease, obesity, major depression, pregnancy-related complications, septic syndromes, COVID-19, and thrombotic microangiopathies, among other pathologies, but also in association with cell therapies, such as hematopoietic stem cell transplantation and treatment with chimeric antigen receptor T cells. In these diverse conditions, evidence suggests that the presence and severity of endothelial dysfunction correlate with the severity of the associated disease. More importantly, endothelial dysfunction has a strong diagnostic and prognostic value for the development of critical complications that, although may differ according to the underlying disease, have a vascular background in common. Our multidisciplinary team of women has devoted many years to exploring the role of the endothelium in association with the mentioned diseases and conditions. Our research group has characterized some of the mechanisms and also proposed biomarkers of endothelial damage. A better knowledge would provide therapeutic strategies either to prevent or to treat endothelial dysfunction.

Lysinuric Protein Intolerance and Its Nutritional and Multisystemic Challenges in Pregnancy: A Case Report and Literature Review.

Lysinuric protein intolerance (LPI) is a rare inborn error of metabolism (IEM), classified as an inherited aminoaciduria, caused by mutations in the SLC7A7 gene, leading to a defective cationic amino acid transport. The metabolic adaptations to the demands of pregnancy and delivery cause significant physiological stress, so those patients affected by IEM are at greater risk of decompensation. A 28-year-old woman with LPI had experienced 3 early miscarriages. While pregnancy was finally achieved, diverse nutritional and medical challenges emerged (food aversion, intrauterine growth restriction, bleeding risk, and preeclampsia suspicion), which put both the mother and the fetus at risk. Moreover, the patient requested a natural childbirth (epidural-free, delayed cord clamping). Although the existence of multiple safety concerns rejected this approach at first, the application of novel strategies made a successful delivery possible. This case reinforces that the woman's wish for a non-medicated, low-intervention natural birth should not be automatically discouraged because of an underlying complex metabolic condition. Achieving a successful pregnancy is conceivable thanks to the cooperation of interdisciplinary teams, but it is still important to consider the risks beforehand in order to be prepared for possible additional complications.

Incidence, risk factors, and impact of early cardiac toxicity after allogeneic hematopoietic cell transplant.

This study investigates early cardiac events (ECEs) occurring during the first 180 days after allogeneic hematopoietic cell transplant (allo-HCT) in 416 adults receiving posttransplant cyclophosphamide (PTCY) (n = 258) or not receiving PTCY (n = 158). Total body irradiation (TBI) was given to 133 (31.9%) patients, of whom 111 (83.4%) received TBI combined with PTCY. The day +180 cumulative incidence function (CIF) of ECEs was 8.4%, with heart failure (n = 13) and pericardial complications (n = 11) being the most prevalent complications. The incidence of ECEs was higher in patients receiving PTCY, and receiving TBI. ECEs were more prevalent in haploidentical HCTs than in matched sibling donor, 10/10 HLA-matched unrelated donor, and 9/10 HLA-mismatched unrelated donor allo-HCTs. As for the ECE risk from the combination of PTCY and TBI, the multivariate analysis reported that patients receiving PTCY without TBI, TBI without PTCY, and TBI with PTCY were at higher risk for ECEs compared with patients receiving neither PTCY nor TBI. Pre-existing cardiac morbidity predicted ECEs. However, using high-dose CY-containing preparative regimens did not increase the risk for cardiac toxicity at +180 days after allo-HCT. ECEs were associated with higher nonrelapse mortality and lower overall survival. Considering that PTCY and TBI were predictors for ECEs, and the impact of this complication on transplant mortality, the implementation of cardiac monitoring plans could be appropriate in patients receiving these medications.

Bacterial Bloodstream Infections in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation With Post-Transplantation Cyclophosphamide.

This study investigates the incidence and predictors for bacterial bloodstream infection (BSI) in 330 adults undergoing allo-HCT, and explores the effect of post-transplantation cyclophosphamide (PTCY) on the probability of presenting this complication. All patients received levofloxacin during the aplastic phase. Only the first episode of BSI was counted as an event. Patients were classified into 2 groups: PTCY-based (n = 200) versus other prophylaxis (n = 130). One hundred twenty-four patients were diagnosed with a first episode of BSI, most of them during the first 30 days (70.2%). Proportions of BSIs caused by Gram-positive bacteria were comparable to those caused by Gram-negative bacteria (48.3% versus 45.9%). The cumulative incidence of BSI was higher in patients receiving PTCY than in those receiving other prophylaxis (days 30 and 100: 35.0% and 37.0% versus 13.1% and 18.5%, P < .001). At day 30, the likelihood of BSI was 2.41 (P = .012) times higher in the PTCY group than in the non-PTCY group. The 30-day mortality rate in all patients with BSI was 8.0%, lower (P = .002) in the PTCY group (2.3%) than in the non-PTCY group (21.6%). Finally, the overall survival of patients receiving PTCY and diagnosed with BSI was similar to that of patients without presenting this complication. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

PTCY and Tacrolimus for GVHD Prevention for Older Adults Undergoing HLA-Matched Sibling and Unrelated Donor AlloHCT.

The use of post-transplantation cyclophosphamide (PTCY) for graft-versus-host disease (GHVD) prevention is becoming prevalent in the transplantation community when HLA-identical sibling and 10/10 HLA-matched (MUD) and 9/10 mismatched unrelated donors are selected for alloHSCT. However, reported evidence on outcomes from elderly patients receiving PTCY-containing GVHD prophylaxis remains limited. This study aims to compare the outcomes of PTCY- tacrolimus (TK) prophylaxis and conventional GVHD prophylaxis in patients aged >50 years undergoing peripheral blood alloHSCT from a single institution. A total of 161 consecutive patients aged >50 years undergoing alloHSCT between January 2014 and February 2021 were included. Data were collected retrospectively and updated in December 2021. Patients received grafts from HLA-identical sibling, and from 10/10 and 9/10 HLA matched and mismatched unrelated donors. Overall, median age was 60 years, and 91 (54.8%) received PTCY-TK for GVHD prevention. Time to neutrophil and platelet engraftment was longer in the PTCY-TK group (20 versus 16 days and 19 versus 11 days, P < .001). The cumulative incidences of grade II-IV and III-IV acute GVHD (aGVHD) at day 100 and moderate/severe chronic GVHD (cGVHD) at 2 years were 18.2%, 5.7%, and 9.5% for patients receiving PTCY-TK, and 26.0%, 9.6% and 39.5% for those who did not. The multivariate analysis showed that PTCY-TK reduced the probability of grade II-IV aGVHD (hazard ratio [HR] 0.41, P = .035), of cGVHD (any grade: HR 0.43 [P = .014], and of moderate/severe cGVHD [HR 0.15 {P < .001}]). At 2 years, the overall survival (65.4% versus 65.6%, P = .472), non-relapse mortality (17.4% versus 13.7%, P = .967), and cumulative incidence of relapse rates (24.2% versus 27.5%, P = .712) were comparable between both cohorts; GVHD-free/relapse-free survival (GRFS) was higher in the PTCY-TK group (2 years: 50.2% versus 21.8%; HR 0.42, P = .001). In patients aged ≥50 years. PTCY-TK was safe and a more effective drug combination than non-PTCY containing GVHD prophylaxis, even with the use of matched and mismatched unrelated donors, and resulted in comparable relapse rates and better GRFS.

Efficacy of early transfusion of convalescent plasma with high-titer SARS-CoV-2 neutralizing antibodies in hospitalized patients with COVID-19.

BACKGROUND: Despite most controlled trials have shown no measurable benefit of COVID-19 convalescent plasma (CCP) in patients with COVID-19, some studies suggest that early administration of CCP with high-titer anti-SARS-CoV-2 can be beneficial in selected patients. We investigated the efficacy of early administration of high-titer CCP to patients with COVID-19 who required hospitalization, STUDY DESIGN AND METHODS: Observational, propensity score (PS) matched case-control study of COVID-19 patients treated with CCP within 72 h of hospital admission and untreated controls from August 2020 to February 2021. All CCP donations had a Euroimmun anti-SARS-CoV-2 sample-to-cutoff ratio ≥3. PS matching was based on prognostic factors and presented features with high-standardized differences between the treated and control groups. The primary endpoint was mortality within 30 days of diagnosis. RESULTS: A total of 1604 patients were analyzed, 261 of whom received CCP, most (82%) within 24 h after admission. Median age was 67 years (interquartile range: 56-79), and 953 (60%) were men. Presenting factors independently associated with higher 30-day mortality were increased age, cardiac disease, hypoxemic respiratory failure, renal failure, and plasma d-dimer >700 ng/ml. After PS matching, transfusion of CCP was associated with a significant reduction in the 30-day mortality rate (odds ratio [OR]; 0.94, 95% confidence interval [CI]: 0.91-0.98; p = .001) that extended to the 60th day after COVID-19 diagnosis (OR: 0.95; 95% CI: 0.92-0.99; p = .01). CONCLUSION: Our results suggest that CCP can still be helpful in selected patients with COVID-19 and call for further studies before withdrawing CCP from the COVID-19 therapeutic armamentarium.

Recent developments and persisting challenges in the prevention and treatment of venous thromboembolism in patients with hematological malignancies.

Venous thromboembolism (VTE) is a common complication of cancer. Its treatment is challenging because of the high risk for both VTE recurrence and bleeding. Evidence is particularly scarce for patients with hematological malignancies. This review aims to summarize new developments in anticoagulation for the prevention and treatment of VTE in patients with active cancer, largely derived from the formal introduction of direct anticoagulants (DOACs) in this population. We then offer our recommendations for the thromboprophylaxis and treatment of VTE in patients with hematological disorders (mature lymphoid disorders, plasma cell disorders, myeloproliferative neoplasms, myelodysplastic syndrome and acute leukemia/stem cell transplant). We conclude by emphasizing the lack of high-quality evidence in a majority of these settings, caution about the use of DOACs in clinical situations where evidence is lacking and, finally, note the importance of involving patients in the decision-making process.

Conventional and molecular cytogenetic studies to characterize 32 complex variant Philadelphia translocations in patients with chronic myeloid leukemia.

BCR/ABL1 gene fusion is the hallmark of chronic myeloid leukemia (CML), and is generated in 5-10% of patients by a variant translocation involving 9q34, 22q11.2 and one or more additional genomic regions. The objective of the present study was to characterize, by conventional and molecular cytogenetics, 32 complex variant Philadelphia (Ph) translocations present at diagnosis in patients with CML. The chromosomes most frequently involved were 1 and 5, and the breakpoint most frequently involved was 12p13. The q-chromosome arm was more frequently involved (60%) than the p-arm. The breakpoints were located in the G-light bands in the majority of cases (85%). Additional chromosomal abnormalities were observed in 6 out of 32 (19%) patients. In conclusion, the combination of conventional and molecular cytogenetics studies has allowed us to: i) Detect and quantify the BCR/ABL1 fusion gene; ii) characterize the complex variant translocations and detect cryptic translocations; iii) confirm that the breakpoints are commonly localized in the G-light bands; (iv) confirm that the genesis of variant translocations could be via either the one-step or two-step mechanisms; and v) to report new cases of complex variant translocations.

Serotonin receptor type 1B constitutes a therapeutic target for MDS and CMML.

Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) are chronic myeloid clonal neoplasms. To date, the only potentially curative therapy for these disorders remains allogeneic hematopoietic progenitor cell transplantation (HCT), although patient eligibility is limited due to high morbimortality associated with this procedure coupled with advanced age of most patients. Dopamine receptors (DRs) and serotonin receptors type 1 (HTR1s) were identified as cancer stem cell therapeutic targets in acute myeloid leukemia. Given their close pathophysiologic relationship, expression of HTR1s and DRs was interrogated in MDS and CMML. Both receptors were differentially expressed in patient samples compared to healthy donors. Treatment with HTR1B antagonists reduced cell viability. HTR1 antagonists showed a synergistic cytotoxic effect with currently approved hypomethylating agents in AML cells. Our results suggest that HTR1B constitutes a novel therapeutic target for MDS and CMML. Due to its druggability, the clinical development of new regimens based on this target is promising.

Clinical and biological significance of isolated Y chromosome loss in myelodysplastic syndromes and chronic myelomonocytic leukemia. A report from the Spanish MDS Group.

Isolate loss of chromosome Y (-Y) in myelodysplastic syndromes (MDS) is associated to a better outcome but it is also well described as an age-related phenomenon. In this study we aimed to analyze the prognostic impact of -Y in the context of the IPSS-R cytogenetic classification, evaluate the clinical significance of the percentage of metaphases with isolated -Y, and test whether finding -Y may predispose to over-diagnose MDS in patients with borderline morphological features. We evaluated 3581 male patients from the Spanish MDS Registry with a diagnosis of MDS or chronic myelomonocytic leukemia (CMML). -Y was identified in 177 patients (4.9%). Compared with the 2246 male patients with normal karyotype, -Y group showed a reduced risk of leukemic transformation that did not translate into a survival advantage. The overall survival and the risk of leukemic transformation were not influenced by the percentage of metaphases with -Y. The -Y group was not enriched in patients with minor morphologic traits of dysplasia, suggesting that the better outcome in the -Y group cannot be explained by enrichment in cases misdiagnosed as MDS. In conclusion, our results support the current recommendation of classifying patients with -Y within the very good risk category of the IPSS-R for MDS and rule out a selection bias as a possible explanation of this better outcome. An analysis of the molecular basis of MDS with isolated -Y would be of interest as it may provide a biological basis of protection against progression to acute leukemia.

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.

Excess mortality in the myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are the commonest hematologic malignancies in the elderly. Since many patients with MDS actually die from age-related ailments, the very disease burden of MDS remains largely unknown. This registry-based study was aimed at investigating the excess mortality attributable to MDS. We analyzed 7,408 adult patients diagnosed with primary MDS from 1980 to 2014. Excess mortality was estimated by comparing the patients' survival with that expected in the matched general population. Median age of patients was 74 years, 58% were males, and 65% belonged to the lower risk categories of the Revised International Prognostic Scoring System (IPSS-R). Excess mortality accounted for three-fourths of the all-cause mortality and was mainly driven by factors unrelated to leukemic transformation. Excess mortality increased with the IPSS-R risk category [Incidence rate ratio (IRR): 2.1, 95% CI: 1.9-2.3; P < .001]. Older age and male sex retained an independent association with higher excess mortality after discounting demographic effects. Excess mortality increased in the most recent periods just in the higher risk IPSS-R categories (IRR: 1.2; 95% CI: 1.1-1.3 when comparing periods 2007-14, 2000-06, and 1980-99). In conclusion, MDS carry a significant excess mortality, even in the lower risk categories, that is mainly driven by factors unrelated to leukemic transformation, and increases with older age, male sex, and poorer risk categories. Excess mortality has increased in recent years in the higher risk patients, which might be ascribed to a parallel increase in age-related comorbidities. Our results claim for more comprehensive treatment strategies for patients with MDS. Am. J. Hematol. 92:149-154, 2017. © 2016 Wiley Periodicals, Inc.

Repositioning of bromocriptine for treatment of acute myeloid leukemia.

BACKGROUND: Treatment for acute myeloid leukemia (AML) has not significantly changed in the last decades and new therapeutic approaches are needed to achieve prolonged survival rates. Leukemia stem cells (LSC) are responsible for the initiation and maintenance of AML due to their stem-cell properties. Differentiation therapies aim to abrogate the self-renewal capacity and diminish blast lifespan. METHODS: An in silico screening was designed to search for FDA-approved small molecules that potentially induce differentiation of AML cells. Bromocriptine was identified and validated in an in vitro screening. Bromocriptine is an approved drug originally indicated for Parkinson's disease, acromegaly, hyperprolactinemia and galactorrhoea, and recently repositioned for diabetes mellitus. RESULTS: Treatment with bromocriptine reduced cell viability of AML cells by activation of the apoptosis program and induction of myeloid differentiation. Moreover, the LSC-enriched primitive AML cell fraction was more sensitive to the presence of bromocriptine. In fact, bromocriptine decreased the clonogenic capacity of AML cells. Interestingly, a negligible effect is observed in healthy blood cells and hematopoietic stem/progenitor cells. CONCLUSIONS: Our results support the use of bromocriptine as an anti-AML drug in a repositioning setting and the further clinical validation of this preclinical study.

Emetine induces chemosensitivity and reduces clonogenicity of acute myeloid leukemia cells.

Acute myeloid leukemia (AML) is an hematologic neoplasia characterized by the accumulation of transformed immature myeloid cells in bone marrow. Although the response rate to induction therapy is high, survival rate 5-year after diagnosis is still low, highlighting the necessity of new novel agents. To identify agents with the capability to abolish the self-renewal capacity of AML blasts, an in silico screening was performed to search for small molecules that induce terminal differentiation. Emetine, a hit compound, was validated for its anti-leukemic effect in vitro, ex vivo and in vivo. Emetine, a second-line anti-protozoa drug, differentially reduced cell viability and clonogenic capacity of AML primary patient samples, sparing healthy blood cells. Emetine treatment markedly reduced AML burden in bone marrow of xenotransplanted mice and decreased self-renewal capacity of the remaining engrafted AML cells. Emetine also synergized with commonly used chemotherapeutic agents such as ara-C. At a molecular level, emetine treatment was followed by a reduction in HIF-1α protein levels. This study validated the anti-leukemiceffect of emetine in AML cell lines, a group of diverse AML primary samples, and in a human AML-transplanted murine model, sparing healthy blood cells. The selective anti-leukemic effect of emetine together with the safety of the dose range required to exert this effect support the development of this agent in clinical practice.

Refining the Breakpoints of Three New Translocations Identified in Myelodysplastic Syndromes.

Recurrent translocations are uncommon in myelodysplastic syndromes (MDS). Three new recurrent translocations, namely der(12)t(3;12)(q13;p13), t(11;13;22)(q13;q14;q12) and der(17)t(13;17)(q21;p13), identified by conventional cytogenetics (CC) in 4 MDS patients, were further characterized using a panel of commercial and homemade fluorescence in situ hybridization (FISH) probes. The goal of this study was to determine the precise breakpoints and to identify genes that could be related with the neoplastic process. Half of the breakpoints (4/8) were precisely identified and in the remaining half they were narrowed to a region ranging from 14 to 926 kb. All the studied breakpoints had interstitial or terminal deletions ranging from 536 kb to 89 Mb, and only those 7 Mb were detected by CC. The genes located in or around the breakpoints described in our study have not been previously related to MDS. The deleted regions include the ETV6 and RB1 genes, among others, and exclude the TP53 gene. FISH studies were useful to refine the breakpoints of the translocations, but further studies are needed to determine the role of the involved genes in the neoplastic process.

Prognostic impact of chromosomal translocations in myelodysplastic syndromes and chronic myelomonocytic leukemia patients. A study by the spanish group of myelodysplastic syndromes.

Chromosomal translocations are rare in the myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). With the exception of t(3q), translocations are not explicitly considered in the cytogenetic classification of the IPSS-R and their impact on disease progression and patient survival is unknown. The present study was aimed at determining the prognostic impact of translocations in the context of the cytogenetic classification of the IPSS-R. We evaluated 1,653 patients from the Spanish Registry of MDS diagnosed with MDS or CMML and an abnormal karyotype by conventional cytogenetic analysis. Translocations were identified in 168 patients (T group). Compared with the 1,485 patients with abnormal karyotype without translocations (non-T group), the T group had a larger proportion of patients with refractory anemia with excess of blasts and higher scores in both the cytogenetic and global IPSS-R. Translocations were associated with a significantly shorter survival and higher incidence of transformation into AML at univariate analysis but both features disappeared after multivariate adjustment for the IPSS-R cytogenetic category. Patients with single or double translocations other than t(3q) had an outcome similar to those in the non-T group in the intermediate cytogenetic risk category of the IPSS-R. In conclusion, the presence of translocations identifies a subgroup of MDS/CMML patients with a more aggressive clinical presentation that can be explained by a higher incidence of complex karyotypes. Single or double translocations other than t(3q) should be explicitly considered into the intermediate risk category of cytogenetic IPSS-R classification.

Treatment with G-CSF reduces acute myeloid leukemia blast viability in the presence of bone marrow stroma.

BACKGROUND: The resulting clinical impact of the combined use of G-CSF with chemotherapy as a chemosensitizing strategy for treatment of acute myeloid leukemia (AML) patients is still controversial. In this study, the effect of ex vivo treatment with G-CSF on AML primary blasts was studied. METHODS: Peripheral blood mononuclear cells from AML patients were treated with G-CSF at increasing doses, alone or in co-culture with HS-5 stromal cells. Cell viability and surface phenotype was determined by flow cytometry 72 h after treatment. For clonogenicity assays, AML primary samples were treated for 18 h with G-CSF at increasing concentrations and cultured in methyl-cellulose for 14 days. Colonies were counted based on cellularity and morphology criteria. RESULTS: The presence of G-CSF reduced the overall viability of AML cells co-cultured with bone marrow stroma; whereas, in absence of stroma, a negligible effect was observed. Moreover, clonogenic capacity of AML cells was significantly reduced upon treatment with G-CSF. Interestingly, reduction in the AML clonogenic capacity correlated with the sensitivity to chemotherapy observed in vivo. CONCLUSIONS: These ex vivo results would provide a biological basis to data available from studies showing a clinical benefit with the use of G-CSF as a priming agent in patients with a chemosensitive AML and would support implementation of further studies exploring new strategies of chemotherapy priming in AML.