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26 result(s) for "Nazha, Aziz"
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Personalized predictions of patient outcomes during and after hospitalization using artificial intelligence
Hospital systems, payers, and regulators have focused on reducing length of stay (LOS) and early readmission, with uncertain benefit. Interpretable machine learning (ML) may assist in transparently identifying the risk of important outcomes. We conducted a retrospective cohort study of hospitalizations at a tertiary academic medical center and its branches from January 2011 to May 2018. A consecutive sample of all hospitalizations in the study period were included. Algorithms were trained on medical, sociodemographic, and institutional variables to predict readmission, length of stay (LOS), and death within 48–72 h. Prediction performance was measured by area under the receiver operator characteristic curve (AUC), Brier score loss (BSL), which measures how well predicted probability matches observed probability, and other metrics. Interpretations were generated using multiple feature extraction algorithms. The study cohort included 1,485,880 hospitalizations for 708,089 unique patients (median age of 59 years, first and third quartiles (QI) [39, 73]; 55.6% female; 71% white). There were 211,022 30-day readmissions for an overall readmission rate of 14% (for patients ≥65 years: 16%). Median LOS, including observation and labor and delivery patients, was 2.94 days (QI [1.67, 5.34]), or, if these patients are excluded, 3.71 days (QI [2.15, 6.51]). Predictive performance was as follows: 30-day readmission (AUC 0.76/BSL 0.11); LOS > 5 days (AUC 0.84/BSL 0.15); death within 48–72 h (AUC 0.91/BSL 0.001). Explanatory diagrams showed factors that impacted each prediction.
Invariant patterns of clonal succession determine specific clinical features of myelodysplastic syndromes
Myelodysplastic syndromes (MDS) arise in older adults through stepwise acquisitions of multiple somatic mutations. Here, analyzing 1809 MDS patients, we infer clonal architecture by using a stringent, the single-cell sequencing validated PyClone bioanalytic pipeline, and assess the position of the mutations within the clonal architecture. All 3,971 mutations are grouped based on their rank in the deduced clonal hierarchy (dominant and secondary). We evaluated how they affect the resultant morphology, progression, survival and response to therapies. Mutations of SF3B1, U2AF1, and TP53 are more likely to be dominant, those of ASXL1, CBL, and KRAS are secondary. Among distinct combinations of dominant/secondary mutations we identified 37 significant relationships, of which 12 affect clinical phenotypes, 5 cooperatively associate with poor prognosis. They also predict response to hypomethylating therapies. The clonal hierarchy has distinct ranking and the resultant invariant combinations of dominant/secondary mutations yield novel insights into the specific clinical phenotype of MDS. Stepwise acquisition of mutations gives rise to myelodysplastic syndrome (MDS) in older adults. Here, the authors infer the clonal hierarchy of 1809 MDS patients, revealing insights into the evolution of dominant/secondary mutations and how these impact clinical phenotypes like leukemic progression and therapy response.
Tet2 loss leads to hypermutagenicity in haematopoietic stem/progenitor cells
TET2 is a dioxygenase that catalyses multiple steps of 5-methylcytosine oxidation. Although TET2 mutations frequently occur in various types of haematological malignancies, the mechanism by which they increase risk for these cancers remains poorly understood. Here we show that Tet2 −/− mice develop spontaneous myeloid, T- and B-cell malignancies after long latencies. Exome sequencing of Tet2 −/− tumours reveals accumulation of numerous mutations, including Apc , Nf1 , Flt3 , Cbl , Notch1 and Mll2 , which are recurrently deleted/mutated in human haematological malignancies. Single-cell-targeted sequencing of wild-type and premalignant Tet2 −/− Lin − c-Kit + cells shows higher mutation frequencies in Tet2 −/− cells. We further show that the increased mutational burden is particularly high at genomic sites that gained 5-hydroxymethylcytosine, where TET2 normally binds. Furthermore, TET2 -mutated myeloid malignancy patients have significantly more mutational events than patients with wild-type TET2 . Thus, Tet2 loss leads to hypermutagenicity in haematopoietic stem/progenitor cells, suggesting a novel TET2 loss-mediated mechanism of haematological malignancy pathogenesis. TET2 catalyses DNA demethylation and is mutated in various blood cancers; in particular Tet2 null mice develop haematological neoplasms. Here the authors show that this effect could be due to the increased frequency of mutation associated with TET2 loss in haematopoietic stem/progenitor cells.
Molecular landscape in acute myeloid leukemia: where do we stand in 2016
Acute myeloid leukemia(AML) is a clonal disorder characterized by the accumulation of complex genomic alterations that define the disease pathophysiology and overall outcome. Recent advances in sequencing technologies have described the molecular landscape of AML and identified several somatic alterations that impact overall survival. Despite all these advancement, several challenges remain in translating this information into effective therapy. Herein we will review the molecular landscape of AML and discuss the impact of the most common somatic mutations on disease biology and outcome.
Mutation clonal burden and allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia and myelodysplastic syndromes
Next generation sequencing (NGS) has become an important tool to inform disease risk for myeloid malignancies, however data remains conflicting regarding the significance of individual mutations. We performed targeted NGS on 112 patients with AML, and 80 with MDS, who underwent allogeneic hematopoietic cell transplantation. The most common mutations in AML were TET2 (14.7%), FLT3 (12.9%), DNMT3A (12.1%), and RUNX1 (7.8%). Complex cytogenetics (HR 2.82, P = .017) and disease status (33% were associated with poor RFS (HR 3.57, P = .017; and HR 6.57, P = .003; respectively). Molecular profiling is increasingly important in the care of patients with AML and MDS. Further studies are needed to understand the molecular complexities, including the significance of clonal burden, to better inform care decisions.
Whole-genome sequencing identifies novel predictors for hematopoietic cell transplant outcomes for patients with myelodysplastic syndrome: a CIBMTR study
Recurrent mutations in TP53, RAS pathway and JAK2 genes were shown to be highly prognostic of allogeneic hematopoietic cell transplant (alloHCT) outcomes in myelodysplastic syndromes (MDS). However, a significant proportion of MDS patients has no such mutations. Whole-genome sequencing (WGS) empowers the discovery of novel prognostic genetic alterations. We conducted WGS on pre-alloHCT whole-blood samples from 494 MDS patients. To nominate genomic candidates and subgroups that are associated with overall survival, we ran genome-wide association tests via gene-based, sliding window and cluster-based multivariate proportional hazard models. We used a random survival forest (RSF) model with build-in cross-validation to develop a prognostic model from identified genomic candidates and subgroups, patient-, disease- and HCT-related clinical factors. Twelve novel regions and three molecular signatures were identified with significant associations to overall survival. Mutations in two novel genes, CHD1 and DDX11 , demonstrated a negative impact on survival in AML/MDS and lymphoid cancer data from the Cancer Genome Atlas (TCGA). From unsupervised clustering of recurrent genomic alterations, genomic subgroup with TP53 /del5q is characterized with the significant association to inferior overall survival and replicated by an independent dataset. From supervised clustering of all genomic variants, more molecular signatures related to myeloid malignancies are characterized from supervised clustering, including Fc-receptor FCGRs, catenin complex CDHs and B-cell receptor regulators MTUS2 / RFTN1 . The RSF model with genomic candidates and subgroups, and clinical variables achieved superior performance compared to models that included only clinical variables.
Context dependent effects of ascorbic acid treatment in TET2 mutant myeloid neoplasia
Loss-of-function TET2 mutations ( TET2 MT ) are common in myeloid neoplasia. TET2, a DNA dioxygenase, requires 2-oxoglutarate and Fe(II) to oxidize 5-methylcytosine. TET2 MT thus result in hypermethylation and transcriptional repression. Ascorbic acid (AA) increases dioxygenase activity by facilitating Fe(III)/Fe(II) redox reaction and may alleviate some biological consequences of TET2 MT by restoring dioxygenase activity. Here, we report the utility of AA in the prevention of TET2 MT myeloid neoplasia (MN), clarify the mechanistic underpinning of the TET2-AA interactions, and demonstrate that the ability of AA to restore TET2 activity in cells depends on N- and C-terminal lysine acetylation and nature of TET2 MT . Consequently, pharmacologic modulation of acetyltransferases and histone deacetylases may regulate TET dioxygenase-dependent AA effects. Thus, our study highlights the contribution of factors that may enhance or attenuate AA effects on TET2 and provides a rationale for novel therapeutic approaches including combinations of AA with class I/II HDAC inhibitor or sirtuin activators in TET2 MT leukemia. Using TET2- and ascorbic acid deficient model systems Guan et al show that long term treatment with ascorbic acid delays myeloid neoplasia in mice and reveal a complex interplay of post-translational modification of lysine residues that modulate TET2 activity in neoplastic evolution.
Prognostic landscape of mitochondrial genome in myelodysplastic syndrome after stem-cell transplantation
Despite mitochondrial DNA (mtDNA) mutations are common events in cancer, their global frequency and clinical impact have not been comprehensively characterized in patients with myelodysplastic neoplasia (also known as myelodysplastic syndromes, MDS). Here we performed whole-genome sequencing (WGS) on samples obtained before allogenic hematopoietic cell transplantation (allo-HCT) from 494 patients with MDS who were enrolled in the Center for International Blood and Marrow Transplant Research. We evaluated the impact of mtDNA mutations on transplantation outcomes, including overall survival (OS), relapse, relapse-free survival (RFS), and transplant-related mortality (TRM). A random survival forest algorithm was applied to evaluate the prognostic performance of models that include mtDNA mutations alone and combined with MDS- and HCT-related clinical factors. A total of 2666 mtDNA mutations were identified, including 411 potential pathogenic variants. We found that overall, an increased number of mtDNA mutations was associated with inferior transplantation outcomes. Mutations in several frequently mutated mtDNA genes ( e.g ., MT-CYB and MT-ND5 ) were identified as independent predictors of OS, RFS, relapse and/or TRM after allo-HCT. Integration of mtDNA mutations into the models based on the Revised International Prognostic Scores (IPSS-R) and clinical factors related to MDS and allo-HCT could capture more prognostic information and significantly improve the prognostic stratification efforts. Our study represents the first WGS effort in MDS receiving allo-HCT and shows that there may be clinical utility of mtDNA variants to predict allo-HCT outcomes in combination with more standard clinical parameters.