Evolving Risk Classifications in AML in a Real-Life Scenario: After Changes upon Changes, Is It More and More Adverse?

Acute myeloid leukemia (AML) is a heterogeneous disease classified into three risk categories (favorable, intermediate and adverse) with significant differences in outcomes. Definitions of risk categories evolve overtime, incorporating advances in molecular knowledge of AML. In this study, we analyzed the impacts of evolving risk classifications in 130 consecutive AML patients in a single-center real-life experience. Complete cytogenetic and molecular data were collected using conventional qPCR and targeted Next Generation Sequencing (NGS). Five-year OS probabilities were consistent among all classification models (roughly 50-72%, 26-32% and 16-20% for favorable, intermediate and adverse risk groups, respectively). In the same way, the medians of survival months and prediction power were similar in all models. In each update, around 20% of patients were re-classified. The adverse category consistently increased over time (31% in MRC, 34% in ELN2010, 50% in ELN2017), reaching up to 56% in the recent ELN2022. Noteworthily, in multivariate models, only age and the presence of TP53 mutations remained statistically significant. With updates in risk-classification models, the percentage of patients assigned to the adverse group is increasing, and so will the indications for allogeneic stem cell transplantation.

First importations of SARS-CoV-2 P.1 and P.2 variants from Brazil to Spain and early community transmission.

INTRODUCTION: SARS-CoV-2variants of concern (VOC) have been described in the UK (B.1.1.7), South Africa (B.1.351) and Brazil (P.1). Among them, the most scarce information has been obtained from the P.1 variant and more data on its global presence and about its spreading dynamics are needed. METHODS: Whole genome sequencing was performed prospectively on travellers arriving from Brazil and on a random selection of SARS-CoV-2 positive cases from our population. RESULTS: In this study we report the first SARS-CoV-2 P.1 and P.2 variants exported from Brazil to Spain. The case infected with the P.1 variant, who had only stayed in Rio de Janeiro, required hospitalisation. The two P.2 cases remained asymptomatic. A wider distribution for P.1 variant beyond the Brazilian Amazonia should be considered. The exportation of the P.2 variant, carrying the E484K mutation, deserves attention. One month after the first description of P.1 and P.2 importations from Brazil to Madrid, these variants were identified circulating in the community, in cases without a travel history, and involved in household transmissions CONCLUSION: Whole genome sequencing of SARS-CoV-2 positive travellers arriving from Brazil allowed us to identify the first importations of P.1 and P.2 variants to Spain and their early community transmission.

First importations of SARS-CoV-2 P.1 and P.2 variants from Brazil to Spain and early community transmission / Primeras importaciones de las variantes SARS-CoV-2 P.1 y P.2 de Brasil a Madrid y transmisión comunitaria

Introduction: SARS-CoV-2variants of concern (VOC) have been described in the UK (B.1.1.7), South Africa (B.1.351) and Brazil (P.1). Among them, the most scarce information has been obtained from the P.1 variant and more data on its global presence and about its spreading dynamics are needed.Methods: Whole genome sequencing was performed prospectively on travellers arriving from Brazil and on a random selection of SARS-CoV-2 positive cases from our population.Results: In this study we report the first SARS-CoV-2 P.1 and P.2 variants exported from Brazil to Spain. The case infected with the P.1 variant, who had only stayed in Rio de Janeiro, required hospitalisation. The two P.2 cases remained asymptomatic. A wider distribution for P.1 variant beyond the Brazilian Amazonia should be considered. The exportation of the P.2 variant, carrying the E484K mutation, deserves attention. One month after the first description of P.1 and P.2 importations from Brazil to Madrid, these variants were identified circulating in the community, in cases without a travel history, and involved in household transmissionsConclusion: Whole genome sequencing of SARS-CoV-2 positive travellers arriving from Brazil allowed us to identify the first importations of P.1 and P.2 variants to Spain and their early community transmission.

Introducción: Se han descrito «variantes de preocupación» (VOC) de SARS-CoV-2 en el Reino Unido (B.1.1.7), Sudáfrica (B.1.351) y Brasil (P.1). Entre ellas, se dispone de información más escasa para la variante P.1 y se necesitan más datos sobre su presencia global y sobre su dinámica de expansión.Métodos: Se realizó secuenciación del genoma completo de forma prospectiva de SARS-CoV-2 en viajeros procedentes de Brasil y en una selección aleatoria de casos positivos de SARS-CoV-2 de nuestra población.Resultados: En este estudio reportamos las primeras variantes de SARS-CoV-2 P.1 y P.2 exportadas desde Brasil a España. El caso infectado por la variante P.1, que solo había permanecido en Río de Janeiro, requirió hospitalización. Los 2 casos de la variante P.2 permanecieron asintomáticos. Se debe considerar una distribución más amplia para la variante P.1 más allá de la Amazonía brasileña. La exportación de la variante P.2, que porta la mutación E484K, merece asimismo atención adicional. Un mes después de la primera descripción de las importaciones de P.1 y P.2 de Brasil a Madrid, se identificaron estas variantes circulando en la comunidad, en casos sin antecedentes de viaje, e implicadas en transmisiones domiciliarias.Conclusión: La secuenciación de genoma completo de viajeros positivos para SARS-CoV-2 procedentes de Brasil nos permitió identificar las primeras importaciones de variantes P.1 y P.2 a España y su transmisión comunitaria precoz.

Systematic Genomic and Clinical Analysis of Severe Acute Respiratory Syndrome Coronavirus 2 Reinfections and Recurrences Involving the Same Strain.

Estimates of the burden of severe acute respiratory syndrome coronavirus 2 reinfections are limited by the scarcity of population-level studies incorporating genomic support. We conducted a systematic study of reinfections in Madrid, Spain, supported by genomic viral analysis and host genetic analysis, to cleanse laboratory errors and to discriminate between reinfections and recurrences involving the same strain. Among the 41,195 cases diagnosed (March 2020-March 2021), 93 (0.23%) had 2 positive reverse transcription PCR tests (55-346 days apart). After eliminating cases with specimens not stored, of suboptimal sequence quality, or belonging to different persons, we obtained valid data from 22 cases. Of those, 4 (0.01%) cases were recurrences involving the same strain; case-patients were 39-93 years of age, and 3 were immunosuppressed. Eighteen (0.04%) cases were reinfections; patients were 19-84 years of age, and most had no relevant clinical history. The second episode was more severe in 8 cases.

First importations of SARS-CoV-2 P.1 and P.2 variants from Brazil to Spain and early community transmission.

Introduction: SARS-CoV-2variants of concern (VOC) have been described in the UK (B.1.1.7), South Africa (B.1.351) and Brazil (P.1). Among them, the most scarce information has been obtained from the P.1 variant and more data on its global presence and about its spreading dynamics are needed. Methods: Whole genome sequencing was performed prospectively on travellers arriving from Brazil and on a random selection of SARS-CoV-2 positive cases from our population. Results: In this study we report the first SARS-CoV-2 P.1 and P.2 variants exported from Brazil to Spain. The case infected with the P.1 variant, who had only stayed in Rio de Janeiro, required hospitalisation. The two P.2 cases remained asymptomatic. A wider distribution for P.1 variant beyond the Brazilian Amazonia should be considered. The exportation of the P.2 variant, carrying the E484K mutation, deserves attention. One month after the first description of P.1 and P.2 importations from Brazil to Madrid, these variants were identified circulating in the community, in cases without a travel history, and involved in household transmissions. Conclusion: Whole genome sequencing of SARS-CoV-2 positive travellers arriving from Brazil allowed us to identify the first importations of P.1 and P.2 variants to Spain and their early community transmission.

Introducción: Se han descrito «variantes de preocupación¼ (VOC) de SARS-CoV-2 en el Reino Unido (B.1.1.7), Sudáfrica (B.1.351) y Brasil (P.1). Entre ellas, se dispone de información más escasa para la variante P.1 y se necesitan más datos sobre su presencia global y sobre su dinámica de expansión. Métodos: Se realizó secuenciación del genoma completo de forma prospectiva de SARS-CoV-2 en viajeros procedentes de Brasil y en una selección aleatoria de casos positivos de SARS-CoV-2 de nuestra población. Resultados: En este estudio reportamos las primeras variantes de SARS-CoV-2 P.1 y P.2 exportadas desde Brasil a España. El caso infectado por la variante P.1, que solo había permanecido en Río de Janeiro, requirió hospitalización. Los 2 casos de la variante P.2 permanecieron asintomáticos. Se debe considerar una distribución más amplia para la variante P.1 más allá de la Amazonía brasileña. La exportación de la variante P.2, que porta la mutación E484K, merece asimismo atención adicional. Un mes después de la primera descripción de las importaciones de P.1 y P.2 de Brasil a Madrid, se identificaron estas variantes circulando en la comunidad, en casos sin antecedentes de viaje, e implicadas en transmisiones domiciliarias. Conclusión: La secuenciación de genoma completo de viajeros positivos para SARS-CoV-2 procedentes de Brasil nos permitió identificar las primeras importaciones de variantes P.1 y P.2 a España y su transmisión comunitaria precoz.

SARS-CoV-2 B.1.1.7 Decline Is Not Driven by the Introduction of a More Successful Variant.

The SARS-CoV-2 variant of concern (VOC) Delta (B.617.2 lineage) displaced the predominant VOC Alpha (B.1.1.7 lineage) in the United Kingdom. In Madrid, recent start of the decline of predominant VOC Alpha suggested an equivalent phenomenon. However, 11 different variants, none overrepresented in frequency, occupied progressively over a period of 7 weeks the niche previously dominated by VOC Alpha. Only after these 7 weeks, VOC Delta started to emerge. Viral competition due to the entry of VOC Delta is not the major force driving the start of VOC Alpha decline in Madrid. IMPORTANCE Our data indicate that the dynamics of SARS-CoV-2 VOCs turnover in our setting differ from those proposed for other countries. A systematic genomic analysis, updated on a weekly basis, of representative randomly selected samples of SARS-CoV-2 circulating variants allowed us to define a lapse of 7 weeks between the start of VOC Alpha decline and the final emergence of VOC Delta. During this period, VOC Alpha showed a sustained decline, while 11 VOCs, variants of interest (VOIs), and other identified variants, none overrepresented, occupied the niche left by VOC Alpha. Only after these 7 weeks, emergence of VOC Delta occurred, indicating that viral competition involving VOC Delta was not the exclusive direct driving force behind the starting of VOC Alpha decline.

Shared Mutations in Emerging SARS-CoV-2 Circulating Variants May Lead to Reverse Transcription-PCR (RT-PCR)-Based Misidentification of B.1.351 and P.1 Variants of Concern.

Reverse transcription-PCRs (RT-PCRs) targeting SARS-CoV-2 variant of concern (VOC) mutations have been developed to simplify their tracking. We evaluated an assay targeting E484K/N501Y to identify B.1.351/P1. Whole-genome sequencing (WGS) confirmed only 72 (59.02%) of 122 consecutive RT-PCR P.1/B.1.351 candidates. Prescreening RT-PCRs must target a wider set of mutations, updated from WGS data from emerging variants.

Evaluation of the Alfred AST® system for rapid antimicrobial susceptibility testing directly from positive blood cultures.

To assess the concordance of antimicrobial susceptibility testing results obtained by the Alfred AST® system performed directly from positive blood cultures in comparison with the standard susceptibility test results performed from isolated colonies by an automated broth microdilution method and to determine the applicability of Alfred AST® system in the routine of our blood culture laboratory. This system is based on the detection of growth by turbidimetry through a technology based on light scattering. Antimicrobial susceptibility testing was performed directly from positive bottles by the Alfred AST® system (Alifax, Padova, Italy). The broth microdilution method (MicroScan, Beckman Coulter, CA, USA) performed to the isolates was considered the standard for comparison. We evaluated 115 significant episodes of bacteremia produced by 51 Gram-negative Enterobacterales, 8 Pseudomonas spp., 2 non-fermenting Gram-negative rods, 7 Staphylococcus aureus, 23 coagulase-negative Staphylococcus, 12 Enterococcus spp., and 12 Streptococcus spp. We performed 828 susceptibility determinations with a categorical agreement with the standard method of 97.1%. Only 24 errors (2.9%) were detected. It should be pointed out that for staphylococci and glycopeptides the correlation was only 87% and for non-fermenting Gram-negative rods and piperacillin/tazobactam was only 88.9%. Time to get antibiogram results by Alfred AST® system was 5 versus 48 h for the standard microdilution method from the isolated colonies. The Alfred AST® system is a useful and rapid method to obtain antimicrobial susceptibility results within the same work shift after blood culture positivity.

Asociación de obesidad general y abdominal con hipertensión, dislipemia y presencia de prediabetes en el estudio PREDAPS / Association of general and abdominal obesity with hypertension, dyslipidemia and prediabetes in the PREDAPS study

Introducción y objetivos: Algunas medidas antropométricas muestran mayor capacidad que otras para discriminar la presencia de factores de riesgo cardiovascular. Este trabajo estima la magnitud de la asociación de diversos indicadores antropométricos de obesidad con hipertensión, dislipemia y prediabetes (glucemia basal o glucohemoglobina alteradas). Métodos: Análisis transversal de la información recogida en 2.022 sujetos del estudio PREDAPS (etapa basal). Se definió obesidad general como índice de masa corporal ≥ 30 kg/m2 y obesidad abdominal con 2 criterios: a) perímetro de cintura (PC) ≥ 102 cm en varones/PC ≥ 88 cm en mujeres, y b) índice cintura/estatura (ICE) ≥ 0,55. La magnitud de la asociación se estimó mediante regresión logística. Resultados: La hipertensión arterial mostró la asociación más alta con la obesidad general en mujeres (OR = 3,01; IC95%, 2,24-4,04) y con la obesidad abdominal según el criterio del ICE en varones (OR = 3,65; IC95%, 2,66-5,01). La hipertrigliceridemia y los valores bajos de colesterol unido a lipoproteínas de alta densidad mostraron la asociación más alta con obesidad abdominal según el criterio del ICE en mujeres (OR = 2,49; IC95%, 1,68-3,67 y OR = 2,70; IC95%, 1,89-3,86) y la obesidad general en varones (OR = 2,06; IC95%, 1,56-2,73 y OR = 1,68; IC95%, 1,21-2,33). La prediabetes mostró la asociación más alta con obesidad abdominal según el criterio del ICE en mujeres (OR = 2,48; IC95%, 1,85-3,33) y con obesidad abdominal según el criterio del PC en varones (OR = 2,33; IC95%, 1,75-3,08). Conclusiones: Los indicadores de obesidad abdominal mostraron la mayor asociación con la presencia de prediabetes. La relación de los indicadores antropométricos con hipertensión y con dislipemia mostró resultados heterogéneos (AU)

Introduction and objectives: Some anthropometric measurements show a greater capacity than others to identify the presence of cardiovascular risk factors. This study estimated the magnitude of the association of different anthropometric indicators of obesity with hypertension, dyslipidemia, and prediabetes (altered fasting plasma glucose and/or glycosylated hemoglobin). Methods: Cross-sectional analysis of information collected from 2022 participants in the PREDAPS study (baseline phase). General obesity was defined as body mass index ≥ 30 kg/m2 and abdominal obesity was defined with 2 criteria: a) waist circumference (WC) ≥ 102 cm in men/WC ≥ 88 cm in women, and b) waist-height ratio (WHtR) ≥ 0.55. The magnitude of the association was estimated by logistic regression. Results: Hypertension showed the strongest association with general obesity in women (OR, 3.01; 95%CI, 2.24-4.04) and with abdominal obesity based on the WHtR criterion in men (OR, 3.65; 95%CI, 2.66-5.01). Hypertriglyceridemia and low levels of high-density lipoprotein cholesterol showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.49; 95%CI, 1.68-3.67 and OR, 2.70; 95%CI, 1.89-3.86) and with general obesity in men (OR, 2.06; 95%CI, 1.56-2.73 and OR, 1.68; 95%CI, 1.21-2.33). Prediabetes showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.48; 95%CI, 1.85-3.33) and with abdominal obesity based on the WC criterion in men (OR, 2.33; 95%CI, 1.75-3.08). Conclusions: Abdominal obesity indicators showed the strongest association with the presence of prediabetes. The association of anthropometric indicators with hypertension and dyslipidemia showed heterogeneous results (AU)

Copy number profiling of adult relapsed B-cell precursor acute lymphoblastic leukemia reveals potential leukemia progression mechanisms.

The outcome of relapsed adult acute lymphoblastic leukemia (ALL) remains dismal despite new therapeutic approaches. Previous studies analyzing relapse samples have shown a high degree of heterogeneity regarding gene alterations without an evident relapse signature. Bone marrow or peripheral blood samples from 31 adult B-cell precursor ALL patients at first relapse, and 21 paired diagnostic samples were analyzed by multiplex ligation probe-dependent amplification (MLPA). Nineteen paired diagnostic and relapse samples of these 21 patients were also analyzed by SNP arrays. A trend to acquire homozygous CDKN2A/B deletions and a significant increase in the number of copy number alterations (CNA) was observed from diagnosis to first relapse. Evolution from an ancestral clone was the main pattern of clonal evolution. Relapse samples were extremely heterogeneous regarding CNA frequencies. However, CDKN2A/B, PAX5, ETV6, ATM, IKZF1, VPREB1, and TP53 deletions and duplications of 1q, 8q, 17q, 21, X/Y PAR1, and Xp were frequently detected at relapse. Duplications of genes involved in cell proliferation, drug resistance and stem cell homeostasis regulation, as well as deletions of KDM6A and STAG2 genes emerged as specific alterations at relapse. Genomics of relapsed adult B-cell precursor ALL is highly heterogeneous, although some recurrent lesions involved in essential pathways deregulation were frequently observed. Selective and simultaneous targeting of these deregulated pathways may improve the results of current salvage therapies.

Patients Lacking a KIR-Ligand of HLA Group C1 or C2 Have a Better Outcome after Umbilical Cord Blood Transplantation.

Donor natural killer (NK) cells can destroy residual leukemic cells after allogeneic hematopoietic stem cell transplantation. This effect is based on the interaction of killer-cell immunoglobulin-like receptors (KIR) of donor NK cells with ligands of the major histocompatibility complex found on the surface of the target cells. HLA-C1 subtypes provide the ligand for KIR2DL2 and KIR2DL3 and the HLA-C2 subtypes for KIR2DL1. We have studied the probability of relapse (PR) after single-unit unrelated cord blood transplantation (UCBT) in relation to the potential graft-vs.-leukemia effect mediated by NK cells present in the umbilical cord blood (UCB) by analyzing KIR-ligand and HLA-C typing of the receptor. Data from 33 consecutive patients given a single unit UCBT were included. We have considered two groups of patients based on the absence or the presence of one of the C-ligands for inhibitory KIR and the incompatibility HLA-C1/2 between UCB and patients. Group 1 (n = 21): the patient lacks a C-ligand for inhibitory KIR present in UCB NK cells, i.e., patients homozygous C1/C1 or C2/C2. Group 2 (n = 12): patients heterozygous C1/C2 in which KIR-mediated graft-vs.-leukemia effect is not expected (presence of both C ligands for inhibitory KIR in the receptor). With a median follow-up post-UCBT of 93 months, patients with absence of a C-ligand for inhibitory KIRs (Group 1) showed a lower actuarial PR than patients with both C-ligands (group 2): 21 ± 10 vs. 68 ± 18% at 2 year and 36 ± 13 vs. 84 ± 14% at 5 years (p = 0.025), respectively. In patients with acute lymphoblastic leukemia, the 2-year PR was 36 ± 21% for group 1 and 66 ± 26% for 2 (p = 0.038). Furthermore, group 1 had a lower incidence of grades II-IV acute graft-vs.-host disease (p = 0.04). In the setting of UCBT, the absence of a C-ligand (C1 or C2) of inhibitory KIR in the patient is associated with lower PR, which is probably due to the graft-vs.-host leukemia effect caused by UCB NK cells that lack a ligand for the inhibitory KIR 2DL1/2DL2/2DL3.

Factores pronósticos clínico-biológicos en pacientes con leucemia aguda mieloblástica en recaída / Clinical and biological prognostic factors in relapsed acute myeloid leukemia patients

Fundamentos y objetivo: La leucemia aguda mieloblástica (LAM) constituye la leucemia más frecuente en adultos. A pesar de los avances en el conocimiento de su patogenia, las tasas de curación no superan el 40%, siendo la recaída de la enfermedad la causa más frecuente de fallo de tratamiento. La recaída ocurre por fenómenos de evolución clonal. En este estudio analizamos los factores pronósticos clínicos y biológicos en pacientes adultos con LAM en recaída. Pacientes y métodos: Analizamos un total de 75 pacientes que presentaron recaída leucémica tras haber alcanzado la remisión completa. Se realizó un estudio inmunofenotípico mediante citometría de flujo y estudio citogenético mediante cariotipo convencional en muestras de médula ósea obtenidas en el momento del diagnóstico y de la recaída. Resultados: La supervivencia global (SG) de la serie fue del 3,7%±2,3, siendo la principal causa de muerte la progresión leucémica (83,3%). Los pacientes con recaídas precoces -antes de 12 meses- y aquellos con riesgo citogenético-molecular adverso presentaron SG significativamente inferiores. En el momento de la recaída el 52,5% de los pacientes mostraron cambios fenotípicos, y el 50%, cambios citogenéticos, sin observarse factores clínicos predictivos de dicha evolución clonal. La evolución clonal fenotípica o citogenética no mostró ningún impacto significativo en la SG. Conclusiones: Los pacientes con recaída de LAM presentan un pronóstico infausto, especialmente aquellos con recidiva precoz y riesgo citogenético-molecular adverso. La evolución clonal fenotípica y/o citogenética ocurre en la mitad de los casos sin factores clínicos predictivos ni impacto pronóstico (AU)

Background and objective: Acute myeloid leukemia (AML) is the most frequent type of acute leukemia in adults. Despite recent advances in the characterization of pathogenesis of AML, the cure rates are under 40%, being leukemia relapse the most common cause of treatment failure. Leukaemia relapse occurs due to clonal evolution or clonal escape. In this study, we aimed to analyze the clinical and biological factors influencing outcomes in patients with AML relapse. Patients and methods: We included a total of 75 AML patients who experienced leukaemia relapse after achieving complete remission. We performed complete immunophenotyping and conventional karyotyping in bone marrow aspirates obtained at diagnosis and at leukemia relapse. Results: Overall survival (OS) of the series was 3.7%±2.3, leukaemia progression being the most common cause of death. Patients relapsing before 12 months and those with adverse cytogenetic-molecular risk had statistically significant worse outcomes. A percentage of 52.5 of patients showed phenotypic changes and 50% cytogenetic changes at relapse. We did not find significant clinical factors predicting clonal evolution. The presence of clonal evolution at relapse did not have a significant impact on outcome. Conclusions: Patients with relapsed AML have a dismal prognosis, especially those with early relapse and adverse cytogenetic-molecular risk. Clonal evolution with phenotypic and cytogenetic changes occurred in half of the patients without predictive clinical factors or impact on outcome (AU)

A case of SRSF2 mutation in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is characterized by extremely variable clinical course indicating substantial differences in the biology of the disease. Molecular characterization provides new insights useful for treatment decision making. We report on a patient diagnosed with CLL, whose disease was characterized by episodes of rapid progression and disease stabilization, and in which a SRSF2 gene mutation was identified in the absence of other commonly known mutations of CLL. To the best of our knowledge this is the first case of SRSF2 gene mutation ever reported in CLL.

[Clinical and biological prognostic factors in relapsed acute myeloid leukemia patients]. / Factores pronósticos clínico-biológicos en pacientes con leucemia aguda mieloblástica en recaída.

BACKGROUND AND OBJECTIVE: Acute myeloid leukemia (AML) is the most frequent type of acute leukemia in adults. Despite recent advances in the characterization of pathogenesis of AML, the cure rates are under 40%, being leukemia relapse the most common cause of treatment failure. Leukaemia relapse occurs due to clonal evolution or clonal escape. In this study, we aimed to analyze the clinical and biological factors influencing outcomes in patients with AML relapse. PATIENTS AND METHODS: We included a total of 75 AML patients who experienced leukaemia relapse after achieving complete remission. We performed complete immunophenotyping and conventional karyotyping in bone marrow aspirates obtained at diagnosis and at leukemia relapse. RESULTS: Overall survival (OS) of the series was 3.7%±2.3, leukaemia progression being the most common cause of death. Patients relapsing before 12 months and those with adverse cytogenetic-molecular risk had statistically significant worse outcomes. A percentage of 52.5 of patients showed phenotypic changes and 50% cytogenetic changes at relapse. We did not find significant clinical factors predicting clonal evolution. The presence of clonal evolution at relapse did not have a significant impact on outcome. CONCLUSIONS: Patients with relapsed AML have a dismal prognosis, especially those with early relapse and adverse cytogenetic-molecular risk. Clonal evolution with phenotypic and cytogenetic changes occurred in half of the patients without predictive clinical factors or impact on outcome.