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1.
Transfusion ; 64(2): 223-235, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38323704

RESUMEN

BACKGROUND: The optimal hemoglobin (Hb) threshold for red blood cell transfusions in adult patients with myelodysplastic syndromes (MDS) has not been defined. STUDY DESIGN AND METHODS: We conducted a pilot randomized multi-center study of two transfusion algorithms (liberal, to maintain Hb 110-120 g/L, transfuse 2 units if Hb < 105 g/L and 1 unit if Hb 105-110 g/L vs. restrictive, 85-105 g/L, transfuse 2 units when Hgb < 85 g/L). Primary objectives were 70% compliance in maintaining the q2 week hemoglobin within the targeted range and the achievement of a 15 g/L difference in pre-transfusion Hb. Secondary outcomes included measures of quality of life (QOL), iron studies and safety. RESULTS: Twenty-eight patients were randomized between February 2015-2020, 13 to the restrictive arm and 15 to the liberal arm in three tertiary care centers. The compliance was 66% and 45% and the mean pre-transfusion Hb thresholds were 86 (standard deviation [SD] 8) and 98 g/L (SD 10) in the restrictive and liberal arms, (mean difference 11.8 g/L, p < .0001), respectively. Patients in the liberal arm experienced a mean of 3.4 (SD 2.6) more transfusion visits and received a mean of 5.3 (SD 5.5) more units of blood during the 12-week study. Ferritin increased by 1043 (SD 1516) IU/L and 148 (SD 1319) IU/L in the liberal and restrictive arms, respectively. Selected QOL scores were superior pre-transfusion and more patients achieved clinically important improvements in the liberal arm compared with the restrictive arm for selected symptoms and function domains. CONCLUSION: The results establish that policies for transfusion support can be delivered in practice at multiple hospitals, but further research is required to understand the full clinical effects and safety of liberal transfusion policies in MDS outpatients.


Asunto(s)
Transfusión de Eritrocitos , Síndromes Mielodisplásicos , Adulto , Humanos , Transfusión de Eritrocitos/métodos , Calidad de Vida , Pacientes Ambulatorios , Proyectos Piloto , Síndromes Mielodisplásicos/terapia , Hemoglobinas/análisis
3.
JMIR Public Health Surveill ; 8(2): e32426, 2022 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-35038302

RESUMEN

BACKGROUND: Early estimates of excess mortality are crucial for understanding the impact of COVID-19. However, there is a lag of several months in the reporting of vital statistics mortality data for many jurisdictions, including across Canada. In Ontario, a Canadian province, certification by a coroner is required before cremation can occur, creating real-time mortality data that encompasses the majority of deaths within the province. OBJECTIVE: This study aimed to validate the use of cremation data as a timely surveillance tool for all-cause mortality during a public health emergency in a jurisdiction with delays in vital statistics data. Specifically, this study aimed to validate this surveillance tool by determining the stability, timeliness, and robustness of its real-time estimation of all-cause mortality. METHODS: Cremation records from January 2020 until April 2021 were compared to the historical records from 2017 to 2019, grouped according to week, age, sex, and whether COVID-19 was the cause of death. Cremation data were compared to Ontario's provisional vital statistics mortality data released by Statistics Canada. The 2020 and 2021 records were then compared to previous years (2017-2019) to determine whether there was excess mortality within various age groups and whether deaths attributed to COVID-19 accounted for the entirety of the excess mortality. RESULTS: Between 2017 and 2019, cremations were performed for 67.4% (95% CI 67.3%-67.5%) of deaths. The proportion of cremated deaths remained stable throughout 2020, even within age and sex categories. Cremation records are 99% complete within 3 weeks of the date of death, which precedes the compilation of vital statistics data by several months. Consequently, during the first wave (from April to June 2020), cremation records detected a 16.9% increase (95% CI 14.6%-19.3%) in all-cause mortality, a finding that was confirmed several months later with cremation data. CONCLUSIONS: The percentage of Ontarians cremated and the completion of cremation data several months before vital statistics did not change meaningfully during the COVID-19 pandemic period, establishing that the pandemic did not significantly alter cremation practices. Cremation data can be used to accurately estimate all-cause mortality in near real-time, particularly when real-time mortality estimates are needed to inform policy decisions for public health measures. The accuracy of this excess mortality estimation was confirmed by comparing it with official vital statistics data. These findings demonstrate the utility of cremation data as a complementary data source for timely mortality information during public health emergencies.


Asunto(s)
COVID-19 , Cremación , Humanos , Ontario/epidemiología , Pandemias , SARS-CoV-2
4.
Lancet Reg Health Am ; 7: 100130, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34927128

RESUMEN

BACKGROUND: The effects of the COVID-19 pandemic on non-natural manners of death in Ontario is not known. Understanding the indirect consequences of the pandemic and related public health measures (i.e. lockdown) fills a vital need to inform best practice in public health and guide policy decisions. METHODS: The Office of the Chief Coroner and the Ontario Forensic Pathology Service (OCC-OFPS) investigate sudden and unexpected deaths in the province of Ontario. The number of homicides, suicides, and accidental deaths (non-natural deaths=77,655) were extracted from the centralized Coroner's Information System database (total deaths=197,966), across four provincially defined stages of lockdown related to the COVID-19 pandemic (March 17 to December 31, 2020), and crude rates (per 100,000 people) were compared to the previous eleven years. FINDINGS: There was no major change to the rate of homicides during 2020 compared to 2009-2019 (RR 1⋅1, 95% CI 0⋅95-1⋅2; p=0⋅19; estimated annual effect=21 more deaths in 2020). The rate of suicides also did not show an overall major change in 2020 (RR 1⋅02, 95% CI 0⋅96-1⋅1; p=0⋅50; estimated annual effect=27 more deaths in 2020). However, during the first stage of lockdown (Stage 0), there was a decrease in the rate of suicides compared to all combinations of recent years from 2013 onwards (RRs 0⋅82-0⋅86, combined 95% CI 0⋅69-0⋅99; max p=0⋅039; estimated effect of 30 less deaths in Stage 0). There was an excess of over 1,500 accidental drug-related deaths that occurred during 2020 (RR 2⋅5, 95% CI 2⋅4-2⋅7; p<0⋅001). This finding held up to 'interrupted time series' robustness testing, indicating that 2020 had substantially more drug-related deaths, even when accounting for the linear increasing trend over time. Although motor vehicle collision associated fatalities appeared to decrease slightly in 2020 (RR 0⋅89, 95% CI 0⋅81-0⋅96; p=0⋅0039; estimated annual effect of 78 less deaths), we could not conclude any lockdown-associated effect, particularly when compared to 2019 (RR 0⋅26, 95% CI 0⋅75-1⋅1; p=0⋅26). INTERPRETATION: In Ontario, the short-term effects of the COVID-19 pandemic did not greatly increase homicide or suicide rates, nor decrease motor vehicle collision fatality rates; however, the longer-term impact of the pandemic remains to be elucidated and ongoing vigilance is warranted in the event that other trends emerge. Accidental drug-related fatalities substantially increased during all stages of the lockdown, marking an urgent need for consideration in policy. These results highlight the vital role of death investigation systems in providing high quality and timely data to inform public health recommendations.

5.
BMC Cancer ; 21(1): 509, 2021 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-33957868

RESUMEN

BACKGROUND: Patients with myelodysplastic syndrome (MDS) require chronic red blood cell (RBC) transfusion due to anemia. Multiple RBC transfusions cause secondary iron overload and subsequent excessive generation of reactive oxygen species (ROS), which leads to mutations, cell death, organ failure, and inferior disease outcomes. We hypothesize that iron loading promotes AML development by increasing oxidative stress and disrupting important signaling pathways in the bone marrow cells (BMCs). Conversely, iron chelation therapy (ICT) may reduce AML risk by lowering iron burden in the iron-loaded animals. METHODS: We utilized a radiation-induced acute myeloid leukemia (RI-AML) animal model. Iron overload was introduced via intraperitoneal injection of iron dextran, and iron chelation via oral gavage of deferasirox. A total of 86 irradiated B6D2F1 mice with various levels of iron burden were monitored for leukemia development over a period of 70 weeks. The Kaplan-Meier estimator was utilized to assess AML free survival. In addition, a second cohort of 30 mice was assigned for early analysis at 5 and 7 months post-irradiation. The BMCs of the early cohort were assessed for alterations of signaling pathways, DNA damage response and gene expression. Statistical significance was established using Student's t-test or ANOVA. RESULTS: Iron loading in irradiated B6D2F1 mice accelerated RI-AML development. However, there was a progressive decrease in AML risk for irradiated mice with increase in iron burden from 7.5 to 15 to 30 mg. In addition, ICT decreased AML incidence in the 7.5 mg iron-loaded irradiated mice, while AML onset was earlier for the 30 mg iron-loaded irradiated mice that received ICT. Furthermore, analysis of BMCs from irradiated mice at earlier intervals revealed accelerated dysregulation of signaling pathways upon iron loading, while ICT partially mitigated the effects. CONCLUSIONS: We concluded that iron is a promoter of leukemogenesis in vivo up to a peak iron dose, but further iron loading decreases AML risk by increasing cell death. ICT can partially mitigate the adverse effects of iron overload, and to maximize its benefit this intervention should be undertaken prior to the development of extreme iron overload.


Asunto(s)
Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/complicaciones , Leucemia Mieloide Aguda/etiología , Leucemia Inducida por Radiación/etiología , Animales , Modelos Animales de Enfermedad , Transfusión de Eritrocitos/efectos adversos , Ratones
6.
Hematology ; 26(1): 88-95, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34000978

RESUMEN

Objectives: Reactive oxygen species (ROS) are under scrutiny as a participant in the pathophysiology of myelodysplastic syndrome (MDS) and the progression of MDS to acute myeloid leukemia (AML). Measurement of intracellular ROS (iROS) is particularly important since iROS is a direct indicator of cellular health and integrity.Methods: We developed a technique to measure standardize iROS (siROS) level in lymphocytes and bone marrow (BM) CD34+ hematopoietic progenitors using the fluorescent probe dichlorofluorescein (DCF). We then quantified the siROS in 38 consecutive BM specimens from 27 MDS patients over the course of 10 months. Disease outcome of these patients were also assessed.Results: High serum ferritin, high blast count and poor IPSS were associated with inferior survival and AML progression in this cohort. High blast MDS patients had lower siROS in their BM CD34+ cells than those of low blast patients, consistent with increased reliance on glycolysis and enhanced ROS defense in high blast MDS. We also observed narrower siROS distribution in the BM CD34+ cells of high blast patients, suggesting that loss of heterogeneity in ROS content accompanies the clonal evolution of MDS. Furthermore, we observed a strong correlation between CD34+ cells siROS and serum ferritin level in high blast patients. In one case, iron chelation therapy (ICT) resulted in parallel decreases in serum ferritin and CD34+ cells siROS.Conclusion: Our findings established the siROS profile in early hematopoietic cells of MDS patients and its relationship with blast count and iron overload.


Asunto(s)
Crisis Blástica/metabolismo , Células Madre Hematopoyéticas/metabolismo , Sobrecarga de Hierro/metabolismo , Leucemia Mieloide Aguda/metabolismo , Síndromes Mielodisplásicos/metabolismo , Anciano , Anciano de 80 o más Años , Crisis Blástica/etiología , Crisis Blástica/patología , Crisis Blástica/terapia , Femenino , Células Madre Hematopoyéticas/patología , Humanos , Sobrecarga de Hierro/complicaciones , Sobrecarga de Hierro/terapia , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/terapia , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/patología , Síndromes Mielodisplásicos/terapia
8.
Br J Haematol ; 191(3): 476-485, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32449174

RESUMEN

Ravulizumab, a novel long-acting complement component 5 (C5) inhibitor administered every 8 weeks (q8w), was non-inferior to eculizumab for all efficacy outcomes in two randomised, open-label, phase 3 trials in C5 inhibitor-naïve (Study 301) and eculizumab-experienced (Study 302) adult patients with paroxysmal nocturnal haemoglobinuria (PNH). This pre-specified analysis characterised ravulizumab pharmacokinetics (PK), pharmacodynamics (PD; free C5 levels), and PD differences between medications (Study 301, n = 246; Study 302, n = 195). Ravulizumab PK parameters were determined using non-compartmental analysis. Serum free C5 was quantified with a Gyros-based fluorescence assay (ravulizumab) and an electrochemiluminescence ligand-binding assay (eculizumab). Ravulizumab PK parameters were numerically comparable in both studies; the median time to maximum concentrations ranged from 2·3 to 2·8 and 2·3 to 2·6 h in studies 301 and 302, respectively. Ravulizumab steady-state serum concentrations were achieved immediately after the first dose and sustained throughout treatment. For ravulizumab, the mean (SD) post hoc terminal elimination half-life was 49·7 (8·9) days. Serum free C5 concentrations <0·5 µg/ml were achieved after the first ravulizumab dose and sustained throughout treatment in both studies. In a minority of patients, free C5 concentrations <0·5 µg/ml were not consistently achieved with eculizumab in either study. Ravulizumab q8w was more consistent in providing immediate, complete, sustained C5 inhibition than eculizumab every-2-weeks in patients with PNH.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacocinética , Complemento C5/inmunología , Inactivadores del Complemento/farmacocinética , Hemoglobinuria Paroxística/tratamiento farmacológico , Hemoglobinuria Paroxística/inmunología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Biomarcadores/sangre , Inactivadores del Complemento/uso terapéutico , Femenino , Hemoglobinuria Paroxística/sangre , Hemoglobinuria Paroxística/diagnóstico , Humanos , Masculino , Terapia Molecular Dirigida , Resultado del Tratamiento
9.
Eur J Haematol ; 102(1): 36-52, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30242915

RESUMEN

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disease characterized by intravascular hemolysis, thrombophilia, and marrow failure. Its phenotype is due to absent or reduced expression of GPI-linked complement regulators and subsequent sensitivity of hematopoietic cells to complement-mediated damage and lysis. Introduction of the terminal complement inhibitor eculizumab drastically improved outcomes in PNH patients; however, despite this improvement, there remain several challenges faced by PNH patients and physicians who care for them. One of the most important is increasing awareness of the heterogeneity with which patients can present, which can lead to significant delays in recognition. Data from the Canadian PNH Registry are presented to demonstrate the variety of presenting symptoms. In Canada, geography precludes consolidation of care to just a few centers, so management is distributed across academic hospitals, linked together as the Canadian PNH Network. The Network over the last several years has developed educational programs and clinical checklists and has worked to standardize access to diagnostics across the country. Herein, we address some of the common diagnostic and therapeutic challenges faced by PNH physicians and give our recommendations. Gaps in knowledge are also addressed, and where appropriate, consensus opinion is provided.


Asunto(s)
Hemoglobinuria Paroxística/terapia , Canadá , Pruebas Diagnósticas de Rutina , Manejo de la Enfermedad , Hemoglobinuria Paroxística/diagnóstico , Hemoglobinuria Paroxística/etiología , Humanos , Técnicas de Diagnóstico Molecular , Sistema de Registros , Evaluación de Síntomas
10.
Leuk Res ; 76: 76-81, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30580105

RESUMEN

BACKGROUND: Severe thrombocytopenia affects 10% of patients with myelodysplastic syndrome (MDS) and is associated with poor outcomes. The role for prophylactic platelet transfusions in the outpatient setting is unknown. OBJECTIVE/METHODS: To audit treatments, bleeding rates, and transfusion requirements of patients with MDS and persistent severe thrombocytopenia (PST) registered in a prospective MDS registry at our center. RESULTS: 99 (17%) of 586 total registry patients had PST; 28 were treated with tranexamic acid alone (TXA), 39 with TXA and prophylactic platelet transfusions (PROPH), 19 with PROPH alone, and 13 were untreated. Median duration of PST was 27 weeks and median overall survival was 0.9 years (95% CI 0.7-1.2). During the PST, 6% (6/99) of patients had a grade 4 bleeding event, from which 4 died. Platelet count at the time of grade 4 bleeding ranged from 2 to 19 × 109/L. 66% (27/41) of patients on TXA alone or untreated required no therapeutic platelet transfusions and experienced no grade 3-4 bleeds. There were no significant differences in grade 3-4 bleeding rates between groups. CONCLUSIONS: Patients with MDS and PST had low rates of major bleeding but poor overall survival. Disparities in clinical practice likely relate to patient and provider heterogeneity and the lack of published evidence. The benefit of TXA and/or prophylactic platelet transfusions would be best evaluated by a randomized controlled trial.


Asunto(s)
Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/epidemiología , Trombocitopenia/epidemiología , Trombocitopenia/etiología , Anciano , Anciano de 80 o más Años , Manejo de la Enfermedad , Femenino , Hemorragia/etiología , Hemorragia/prevención & control , Hemorragia/terapia , Humanos , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/terapia , Evaluación del Resultado de la Atención al Paciente , Recuento de Plaquetas , Transfusión de Plaquetas , Sistema de Registros , Análisis de Supervivencia , Trombocitopenia/diagnóstico , Trombocitopenia/terapia
11.
Biomark Res ; 6: 36, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30555701

RESUMEN

BACKGROUND: In patients with myelodysplastic syndrome (MDS), bone marrow cells have an increased predisposition to apoptosis, yet MDS cells outcompete normal bone marrow (BM)-- suggesting that factors regulating growth potential may be important in MDS. We previously identified v-Erb A related-2 (EAR-2, NR2F6) as a gene involved in control of growth ability. METHODS: Bone marrow obtained from C57BL/6 mice was transfected with a retrovirus containing EAR-2-IRES-GFP. Ex vivo transduced cells were flow sorted. In some experiments cells were cultured in vitro, in other experiments cells were injected into lethally irradiated recipients, along with non-transduced bone marrow cells. Short-hairpin RNA silencing EAR-2 was also introduced into bone marrow cells cultured ex vivo. RESULTS: Here, we show that EAR-2 inhibits maturation of normal BM in vitro and in vivo and that EAR-2 transplant chimeras demonstrate key features of MDS. Competitive repopulation of lethally irradiated murine hosts with EAR-2-transduced BM cells resulted in increased engraftment and increased colony formation in serial replating experiments. Recipients of EAR-2-transduced grafts had hypercellular BM, erythroid dysplasia, abnormal localization of immature precursors and increased blasts; secondary transplantation resulted in acute leukemia. Animals were cytopenic, having reduced numbers of erythrocytes, monocytes and granulocytes. Suspension culture confirmed that EAR-2 inhibits granulocytic and monocytic differentiation, while knockdown induced granulocytic differentiation. We observed a reduction in the number of BFU-E and CFU-GM colonies and the size of erythroid and myeloid colonies. Serial replating of transduced hematopoietic colonies revealed extended replating potential in EAR-2-overexpressing BM, while knockdown reduced re-plating ability. EAR-2 functions by recruitment of histone deacetylases, and inhibition of differentiation in 32D cells is dependent on the DNA binding domain. CONCLUSIONS: This data suggest that NR2F6 inhibits maturation of normal BM in vitro and in vivo and that the NR2F6 transplant chimera system demonstrates key features of MDS, and could provide a mouse model for MDS.

12.
Leuk Res ; 74: 21-41, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30286330

RESUMEN

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.


Asunto(s)
Sobrecarga de Hierro , Síndromes Mielodisplásicos , Canadá , Femenino , Humanos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/metabolismo , Sobrecarga de Hierro/patología , Sobrecarga de Hierro/terapia , Masculino , Estudios Multicéntricos como Asunto , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/metabolismo , Síndromes Mielodisplásicos/patología , Síndromes Mielodisplásicos/terapia , Guías de Práctica Clínica como Asunto
13.
Blood Adv ; 2(17): 2176-2185, 2018 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-30171081

RESUMEN

Ravulizumab (ALXN1210), a humanized monoclonal antibody to complement component C5, was engineered from eculizumab to have a substantially longer terminal half-life, permitting longer dosing intervals for paroxysmal nocturnal hemoglobinuria (PNH) treatment. Two phase 1b/2 multicenter open-label studies evaluated efficacy and safety of multiple doses and regimens of ravulizumab in PNH patients naive to complement-inhibitor treatment. Patients in study 103 (n = 13) received ravulizumab 900 mg (lower trough exposure) or 1800 mg every 4 weeks (higher trough exposure); those in study 201 (n = 26) received 1000 mg every 4, 1600 mg every 6, 2400 mg every 8, or 5400 mg every 12 weeks. Trough exposure levels with study 201 dosing regimens were similar to the study 103 900-mg every-4-weeks regimen. Rapid sustained reduction of plasma lactate dehydrogenase (LDH) occurred across all cohorts (73%-90% at end point vs baseline). A greater proportion of patients had normalized LDH (<234 U/L) at least once from days 29 to 253 in the higher- (85.7%) vs lower-trough-exposure (50.0%-83.3%) cohorts; the weighted average of the proportion of instances of LDH normalization from days 29 to 253 was highest in higher- vs lower-trough-exposure cohorts (62.3% vs 31.4%-54.5%). No patients in the higher-trough-exposure cohort, but 1 to 2 patients in all lower-trough-exposure cohorts, experienced breakthrough hemolysis. Ravulizumab improved quality of life (QoL) measures in all cohorts. Two patients experienced meningococcal infections; both recovered and continued in the study. In summary, ravulizumab provided rapid and sustained reduction in complement-mediated hemolysis and improved QoL at dosing intervals up to 12 weeks. This trial was registered at www.clinicaltrials.gov as #NCT02598583 (study 103) and NCT02605993 (study 201).


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Hemoglobinuria Paroxística/tratamiento farmacológico , Adulto , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Complemento C5/antagonistas & inhibidores , Femenino , Hemólisis/efectos de los fármacos , Humanos , L-Lactato Deshidrogenasa/sangre , Masculino , Persona de Mediana Edad , Calidad de Vida , Resultado del Tratamiento
14.
Exp Hematol ; 59: 60-65, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29195897

RESUMEN

Clonal hematopoiesis of aging and indeterminate potential (ARCH or CHIP), driven mainly by mutations in DNMT3A and TET2, is an emerging public health issue, affecting at least 10-15% of adults older than 65 years. CHIP is associated with increased risks of de novo and therapy-related hematological neoplasms and serves as a reservoir for leukemic relapse. CHIP is also associated with increased all-cause mortality and risk of cardio-metabolic disease. The latter association may be explained, at least in part, by the effects of inactivating mutations in TET2 on progeny macrophages. We and others have shown recently that TET2-deficient macrophages are hyperinflammatory and this may exacerbate processes such as atherosclerosis. We postulated an inflammatory state associated with TET2 inactivation and/or unhealthy aging may also favor TET2-mutant hematopoietic stem and progenitor cell (HSPC) expansion. Herein, we demonstrate a clonogenic advantage for Tet2-knockout murine and TET2-mutant human HSPCs in an in vitro environment that contains the proinflammatory cytokine tumor necrosis factor-alpha (TNFα). This phenotype emerges on chronic TNFα exposure and is associated with myeloid skewing and resistance to apoptosis. To our knowledge, this is the first evidence to suggest that TET2 mutations promote clonal dominance with aging by conferring TNFα resistance to sensitive bone marrow progenitors while also propagating such an inflammatory environment. Normalizing the immune environment may present a novel strategy to control or eradicate mutant CHIP clones.


Asunto(s)
Envejecimiento , Apoptosis , Macrófagos/inmunología , Mutación , Nicho de Células Madre , Factor de Necrosis Tumoral alfa , Anciano , Envejecimiento/genética , Envejecimiento/inmunología , Envejecimiento/patología , Animales , Apoptosis/genética , Apoptosis/inmunología , Proteínas de Unión al ADN , Dioxigenasas , Femenino , Humanos , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Macrófagos/patología , Masculino , Ratones , Ratones Noqueados , Proteínas Proto-Oncogénicas , Nicho de Células Madre/genética , Nicho de Células Madre/inmunología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología
15.
Ann Hematol ; 96(12): 2025-2029, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28975386

RESUMEN

Prediction of response to erythropoietin stimulating agents (ESAs) in anemic MDS patients is often based on the Nordic score. We wished to validate the Nordic score (IWG 2006 response criteria) in a larger cohort and determine if other variables such as IPSS/IPSS-R, ferritin, LDH, and a novel European ESA response score (Santini 2013) were of prognostic importance. We analyzed 208 ESA-treated MDS patients (WHO 2008 criteria) from a prospective registry. Ninety-four and 93% had lower risk scores by IPSS (low/int - 1) and IPSS-R (low/very low), respectively. Erythroid response was achieved in 94 patients (47%); responses were similar with erythropoietin (50%) and darbepoetin (39%; p = 0.2). The Nordic and European scores were both validated on univariate analysis. Variables independently predictive of response in multivariate analysis were low-risk IPSS score (OR 0.1, p = 0.0016) and serum EPO level < 100 mIU/mL (OR 8.7, p < 0.0001). We propose a new ESA response score, consisting of (a) IPSS low score (1 point) and (b) serum EPO levels < 100 mIU/ml (2 points), yielding scores ranging from 0 to 3, with response rates varying from 17 to 81%. The Nordic score has validity but we observed lower than the expected response rates in the best risk group. Our proposed scoring system appears more discriminating but needs validation.


Asunto(s)
Eritropoyetina/sangre , Hematínicos/administración & dosificación , Modelos Biológicos , Síndromes Mielodisplásicos , Sistema de Registros , Canadá , Femenino , Ferritinas/sangre , Humanos , Lactante , Recién Nacido , L-Lactato Deshidrogenasa/sangre , Masculino , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/mortalidad , Estudios Prospectivos
16.
Exp Hematol ; 55: 56-70.e13, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28826859

RESUMEN

Tet methylcytosine dioxygenase 2 (TET2) is one of the earliest and most frequently mutated genes in clonal hematopoiesis of indeterminate potential (CHIP) and myeloid cancers, including myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). TET2 catalyzes the oxidation of 5-methylcytosine to 5-hydroxymethylcytosine, leading to DNA demethylation, and also affects transcription by recruiting histone modifiers. Inactivating TET2 mutations cause epigenetic dysregulation, clonal hematopoietic stem cell (HSC) dominance, and monocytic lineage skewing. Here, we found that Tet2 was the most highly expressed Tet enzyme in murine macrophage (MΦ) differentiation. Tet2 transcription was further induced by lipopolysaccharide (LPS), but not interleukin (IL)-4, stimulation, potentially in a nuclear factor κß-dependent manner. Tet2 loss did not affect early LPS gene responses in vitro, but increased Il-1b, Il-6, and Arginase 1 (Arg1) mRNA expression at later stages of stimulation in bone-marrow-derived MΦs (BMMΦs). Tet2-deficient peritoneal MΦs, however, demonstrated profound, constitutive expression of LPS-induced genes associated with an inflammatory state in vivo. In contrast, Tet2 deficiency did not affect alternative MΦ gene expression significantly in response to IL-4. These results suggested impaired resolution of inflammation in the absence of Tet2 both in vitro and in vivo. For the first time, we also detected TET2 mutations in BMMΦs from MDS and CMML patients and assayed their effects on LPS responses, including their potential influence on human IL-6 expression. Our results show that Tet2 restrains inflammation in murine MΦs and mice, raising the possibility that loss of TET2 function in MΦs may alter the immune environment in the large elderly population with TET2-mutant CHIP and in TET2-mutant myeloid cancer patients.


Asunto(s)
Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica/genética , Inflamación/genética , Macrófagos/metabolismo , Proteínas Proto-Oncogénicas/genética , Animales , Arginasa/genética , Diferenciación Celular/genética , Línea Celular , Células Cultivadas , Dioxigenasas , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-1beta/genética , Interleucina-6/genética , Leucemia Mielomonocítica Crónica/genética , Leucemia Mielomonocítica Crónica/patología , Lipopolisacáridos/farmacología , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología
17.
Br J Haematol ; 179(1): 83-97, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28677895

RESUMEN

Analyses suggest iron overload in red blood cell (RBC) transfusion-dependent (TD) patients with myleodysplastic syndrome (MDS) portends inferior overall survival (OS) that is attenuated by iron chelation therapy (ICT) but may be biassed by unbalanced patient-related factors. The Canadian MDS Registry prospectively measures frailty, comorbidity and disability. We analysed OS by receipt of ICT, adjusting for these patient-related factors. TD International Prognostic Scoring System (IPSS) low and intermediate-1 risk MDS, at RBC TD, were included. Predictive factors for OS were determined. A matched pair analysis considering age, revised IPSS, TD severity, time from MDS diagnosis to TD, and receipt of disease-modifying agents was conducted. Of 239 patients, 83 received ICT; frailty, comorbidity and disability did not differ from non-ICT patients. Median OS from TD was superior in ICT patients (5·2 vs. 2·1 years; P < 0·0001). By multivariate analysis, not receiving ICT independently predicted inferior OS, (hazard ratio for death 2·0, P = 0·03). In matched pair analysis, OS remained superior for ICT patients (P = 0·02). In this prospective, non-randomized analysis, receiving ICT was associated with superior OS in lower IPSS risk MDS, adjusting for age, frailty, comorbidity, disability, revised IPSS, TD severity, time to TD and receiving disease-modifying agents. This provides additional evidence that ICT may confer clinical benefit.


Asunto(s)
Transfusión de Eritrocitos/efectos adversos , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Síndromes Mielodisplásicos/mortalidad , Anciano , Anciano de 80 o más Años , Canadá/epidemiología , Causas de Muerte , Terapia por Quelación , Comorbilidad , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Sobrecarga de Hierro/sangre , Sobrecarga de Hierro/epidemiología , Sobrecarga de Hierro/etiología , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/complicaciones , Síndromes Mielodisplásicos/epidemiología , Síndromes Mielodisplásicos/terapia , Pronóstico , Sistema de Registros , Riesgo , Análisis de Supervivencia , Trasplante Homólogo
18.
Br J Haematol ; 174(1): 88-101, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26991631

RESUMEN

UNLABELLED: Little is known about the effects of frailty, disability and physical functioning on the clinical outcomes for myelodysplastic syndromes (MDS). We investigated the predictive value of these factors on overall survival (OS) in 445 consecutive patients with MDS and chronic monomyelocytic leukaemia (CMML) enrolled in a multi-centre prospective national registry. Frailty, comorbidity, instrumental activities of daily living, disability, quality of life, fatigue and physical performance measures were evaluated at baseline and were added as covariates to conventional MDS-related factors as predictors of OS in Cox proportional hazards models. The median age was 73 years, and 79% had revised International Prognostic Scoring System (IPSS-R) risk scores of intermediate or lower. Frailty correlated only modestly with comorbidity. OS was significantly shorter for patients with higher frailty and comorbidity scores, any disability, impaired grip strength and timed chair stand tests. By multivariate analysis, the age-adjusted IPSS-R, frailty (Hazard ratio 2·7 (95% confidence interval [CI] 1·7-4·2), P < 0·0001) and Charlson comorbidity score (Hazard ratio 1·8 (95% CI 1·1-2·8), P = 0·01) were independently prognostic of OS. Incorporation of frailty and comorbidity scores improved risk stratification of the IPSS-R by 30% and 5%, respectively. These data demonstrate for the first time, the importance of considering frailty in prognostic models and a potential target for therapeutic intervention in optimizing clinical outcomes in older MDS patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02537990.


Asunto(s)
Síndromes Mielodisplásicos/mortalidad , Actividades Cotidianas , Anciano , Comorbilidad , Femenino , Anciano Frágil , Humanos , Leucemia Mielomonocítica Crónica/mortalidad , Masculino , Estudios Prospectivos , Calidad de Vida , Sistema de Registros , Factores de Riesgo , Tasa de Supervivencia
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