Exit of pediatric pre-B acute lymphoblastic leukaemia cells from the bone marrow to the peripheral blood is not associated with cell maturation or alterations in gene expression

<p>Abstract</p> <p>Background</p> <p>Childhood pre-B acute lymphoblastic leukemia (ALL) is a bone marrow (BM) derived disease, which often disseminates out of the BM cavity, where malignant cells to a variable degree can be found circulating in the peripheral blood (PB). Normal pre-B cells are absolutely dependent on BM stroma for survival and differentiation. It is not known whether transformed pre-B ALL cells retain any of this dependence, which possibly could impact on drug sensitivity or MRD measurements.</p> <p>Results</p> <p>Pre-B ALL cells, highly purified by a novel method using surface expression of CD19 and immunoglobulin light chains, from BM and PB show a very high degree of similarity in gene expression patterns, with differential expression of vascular endothelial growth factor (VEGF) as a notable exception. In addition, the cell sorting procedure revealed that in 2 out of five investigated patients, a significant fraction of the malignant cells had matured beyond the pre-B cell stage.</p> <p>Conclusion</p> <p>The transition of ALL cells from the BM into the circulation does not demand, or result in, major changes of gene expression pattern. This might indicate an independence of BM stroma on the part of transformed pre-B cells, which contrasts with that of their normal counterparts.</p

DNA Methylation Signatures Predict Cytogenetic Subtype and Outcome in Pediatric Acute Myeloid Leukemia (AML)

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease composed of clinically relevant subtypes defined by recurrent cytogenetic aberrations. The majority of the aberrations used in risk grouping for treatment decisions are extensively studied, but still a large proportion of pediatric AML patients remain cytogenetically undefined and would therefore benefit from additional molecular investigation. As aberrant epigenetic regulation has been widely observed during leukemogenesis, we hypothesized that DNA methylation signatures could be used to predict molecular subtypes and identify signatures with prognostic impact in AML. To study genome-wide DNA methylation, we analyzed 123 diagnostic and 19 relapse AML samples on Illumina 450k DNA methylation arrays. We designed and validated DNA methylation-based classifiers for AML cytogenetic subtype, resulting in an overall test accuracy of 91%. Furthermore, we identified methylation signatures associated with outcome in t(8;21)/RUNX1-RUNX1T1, normal karyotype, and MLL/KMT2A-rearranged subgroups (p < 0.01). Overall, these results further underscore the clinical value of DNA methylation analysis in AML

DNA Methylation Signatures Predict Cytogenetic Subtype and Outcome in Pediatric Acute Myeloid Leukemia (AML)

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease composed of clinically relevant subtypes defined by recurrent cytogenetic aberrations. The majority of the aberrations used in risk grouping for treatment decisions are extensively studied, but still a large proportion of pediatric AML patients remain cytogenetically undefined and would therefore benefit from additional molecular investigation. As aberrant epigenetic regulation has been widely observed during leukemogenesis, we hypothesized that DNA methylation signatures could be used to predict molecular subtypes and identify signatures with prognostic impact in AML. To study genome-wide DNA methylation, we analyzed 123 diagnostic and 19 relapse AML samples on Illumina 450k DNA methylation arrays. We designed and validated DNA methylation-based classifiers for AML cytogenetic subtype, resulting in an overall test accuracy of 91%. Furthermore, we identified methylation signatures associated with outcome in t(8;21)/RUNX1-RUNX1T1, normal karyotype, and MLL/KMT2A-rearranged subgroups (p < 0.01). Overall, these results further underscore the clinical value of DNA methylation analysis in AML

Optimized cytogenetic risk-group stratification of KMT2A-rearranged pediatric acute myeloid leukemia

A comprehensive international consensus on the cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1256 children with KMT2A-r AML aims to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs) and to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared with our previous study, 3 additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, and 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8%-76.2%; P &lt; .01). ACAs occurred in 46.8% of 1200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P &lt; .01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcomes was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate 5 adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine the risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcomes and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs.</p

A Nested Case-Control Study of Metabolically Defined Body Size Phenotypes and Risk of Colorectal Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC).

BACKGROUND: Obesity is positively associated with colorectal cancer. Recently, body size subtypes categorised by the prevalence of hyperinsulinaemia have been defined, and metabolically healthy overweight/obese individuals (without hyperinsulinaemia) have been suggested to be at lower risk of cardiovascular disease than their metabolically unhealthy (hyperinsulinaemic) overweight/obese counterparts. Whether similarly variable relationships exist for metabolically defined body size phenotypes and colorectal cancer risk is unknown. METHODS AND FINDINGS: The association of metabolically defined body size phenotypes with colorectal cancer was investigated in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Metabolic health/body size phenotypes were defined according to hyperinsulinaemia status using serum concentrations of C-peptide, a marker of insulin secretion. A total of 737 incident colorectal cancer cases and 737 matched controls were divided into tertiles based on the distribution of C-peptide concentration amongst the control population, and participants were classified as metabolically healthy if below the first tertile of C-peptide and metabolically unhealthy if above the first tertile. These metabolic health definitions were then combined with body mass index (BMI) measurements to create four metabolic health/body size phenotype categories: (1) metabolically healthy/normal weight (BMI < 25 kg/m2), (2) metabolically healthy/overweight (BMI ≥ 25 kg/m2), (3) metabolically unhealthy/normal weight (BMI < 25 kg/m2), and (4) metabolically unhealthy/overweight (BMI ≥ 25 kg/m2). Additionally, in separate models, waist circumference measurements (using the International Diabetes Federation cut-points [≥80 cm for women and ≥94 cm for men]) were used (instead of BMI) to create the four metabolic health/body size phenotype categories. Statistical tests used in the analysis were all two-sided, and a p-value of <0.05 was considered statistically significant. In multivariable-adjusted conditional logistic regression models with BMI used to define adiposity, compared with metabolically healthy/normal weight individuals, we observed a higher colorectal cancer risk among metabolically unhealthy/normal weight (odds ratio [OR] = 1.59, 95% CI 1.10-2.28) and metabolically unhealthy/overweight (OR = 1.40, 95% CI 1.01-1.94) participants, but not among metabolically healthy/overweight individuals (OR = 0.96, 95% CI 0.65-1.42). Among the overweight individuals, lower colorectal cancer risk was observed for metabolically healthy/overweight individuals compared with metabolically unhealthy/overweight individuals (OR = 0.69, 95% CI 0.49-0.96). These associations were generally consistent when waist circumference was used as the measure of adiposity. To our knowledge, there is no universally accepted clinical definition for using C-peptide level as an indication of hyperinsulinaemia. Therefore, a possible limitation of our analysis was that the classification of individuals as being hyperinsulinaemic-based on their C-peptide level-was arbitrary. However, when we used quartiles or the median of C-peptide, instead of tertiles, as the cut-point of hyperinsulinaemia, a similar pattern of associations was observed. CONCLUSIONS: These results support the idea that individuals with the metabolically healthy/overweight phenotype (with normal insulin levels) are at lower colorectal cancer risk than those with hyperinsulinaemia. The combination of anthropometric measures with metabolic parameters, such as C-peptide, may be useful for defining strata of the population at greater risk of colorectal cancer

Duplex Sequencing Uncovers Recurrent Low-frequency Cancer-associated Mutations in Infant and Childhood KMT2A-rearranged Acute Leukemia

Infant acute lymphoblastic leukemia (ALL) with KMT2A-gene rearrangements (KMT2A-r) have few mutations and a poor prognosis. To uncover mutations that are below the detection of standard next-generation sequencing (NGS), a combination of targeted duplex sequencing and NGS was applied on 20 infants and 7 children with KMT2A-r ALL, 5 longitudinal and 6 paired relapse samples. Of identified nonsynonymous mutations, 87 had been previously implicated in cancer and targeted genes recurrently altered in KMT2A-r leukemia and included mutations in KRAS, NRAS, FLT3, TP53, PIK3CA, PAX5, PIK3R1, and PTPN11, with infants having fewer such mutations. Of identified cancer-associated mutations, 62% were below the resolution of standard NGS. Only 33 of 87 mutations exceeded 2% of cellular prevalence and most-targeted PI3K/RAS genes (31/33) and typically KRAS/NRAS. Five patients only had low-frequency PI3K/RAS mutations without a higher-frequency signaling mutation. Further, drug-resistant clones with FLT3 D835H or NRAS G13D/G12S mutations that comprised only 0.06% to 0.34% of diagnostic cells, expanded at relapse. Finally, in longitudinal samples, the relapse clone persisted as a minor subclone from diagnosis and through treatment before expanding during the last month of disease. Together, we demonstrate that infant and childhood KMT2A-r ALL harbor low-frequency cancer-associated mutations, implying a vast subclonal genetic landscape.publishedVersionPeer reviewe

A changed life : patient´s perspective on chronic heart failure

Bakgrund: Kronisk hjärtsvikt är en av de snabbast växande sjukdomarna globalt, en av fem drabbas under en livstid. Sjukdomen är komplex och progressiv, vilket leder till upprepade kontakter med vården. Sjuksköterskan behöver ha personlig kännedom om patientens erfarenheter av hjärtsvikt för att kunna möta patienten utifrån ett individuellt perspektiv.  Syfte: Syftet med studien var att beskriva hur det ur patientperspektivet är att leva med kronisk hjärtsvikt. Metod: Litteraturstudie utifrån Polit och Beck (2017) flödesschema i nio steg. Åtta artiklar, sju med kvalitativ metod och en med mixad metod, inkluderades efter systematisk sökning av databaserna Cinahl och PubMed. Artiklarna kvalitetsgranskades med hjälp av Polit och Beck (2017) granskningsmallar. Resultat: I resultatet identifierades fyra kategorier känslomässig kris, fysisk begränsning, hantera sjukdomen och nya livsmönster. Slutsats: Studien visar att kronisk hjärtsvikt skapar en fysisk och känslomässig förlust och begränsning av livet. Patienternas strategier för att hantera situationen var olika bland annat beroende på kunskapsnivå och socialt stöd. Patienter utan tillräcklig kunskap kunde inte bearbeta situationen vilket ledde till negativa konsekvenser

Stötvågs- och Splitterbelastade Betongkonstruktioner - Numeriska Studier av Armerad och Fiberarmerad Betong

Concrete is widely used in design of protective structures due to its good energy-absorbing characteristics under high pressures and, when properly reinforced, ductile behaviour. Nevertheless, the response of concrete structures subjected to severe dynamic loading differs from their static behaviour, on a structural level but also on a material level. The addition of steel fibres in the concrete may improve the energy-absorbing characteristics of plain concrete, which is especially true for the tensile behaviour. The fracture energy for steel-fibre reinforced concrete may be many times higher already for low dosages of fibres compared to plain concrete. In design of protective structures it is important to identify the possible threats and their risk of occurrence to be able to characterise the design loads. Often this involves the effects of cased charges, i.e. combined blast and fragment loading. While the structural behaviour for blast load and single fragment impacts is relatively well understood, the response under combined loading, including the blast and multiple impacts of fragments, is not yet clear. The theoretical bases for concrete material behaviour, weapon load characteristics, and their effect on the structural response are treated in this licentiate thesis. In addition, three numerical studies are presented, whose aim is to increase the understanding of impact and impulsive loading and the subsequent response of a concrete element. The first numerical study was a comparative investigation of the relative effect on the impact resistance when adding steel fibres to concrete. It was concluded that the depth of penetration of the striking projectile was only slightly influenced by the addition of fibres, while the sizes of the front- and rear-face craters were decreased. The second numerical study involved combined blast and fragment loading of a reinforced concrete wall strip, and it was seen that the total damage of the wall strip subjected to the combined loads was highly related to the damage caused by the fragment impact alone. Furthermore, the mid-point deflection in combined loading was larger than the sum of mid-point deflections in blast and fragment loading, indicating synergetic effects of the two loads. In the third numerical study the effect of reinforcement on the projectile impact resistance was studied. It was concluded that the presence of reinforcement may improve the impact resistance of the concrete if a suitable reinforcement detailing is used

Vascular density and bone marrow fibrosis in childhood acute lymphoblastic leukemia

Background: In childhood acute lymphoblastic leukemia (ALL), the cure rate has now reached 80% in the western world. Even so, 15¬–20% will die from the disease or treatment-related causes, among them children who did not present any known unfavorable features at diagnosis. Treatment of childhood ALL is risk-adapted, meaning that certain factors that are related to the child or the leukemic blasts stratifies to more or less intensive treatment. In this thesis, characteristics of the bone marrow (BM) stroma, reflecting the interaction between the leukemic cells and their microenvironment, were evaluated. The aims were to investigate these factors in relation to other known data in order to further understand the biology of leukemia, and to suggest additional risk factors that would further improve decision making for the treatment of individual children diagnosed with ALL. Methods: We retrospectively investigated microvessel density (MVD), blast-congested vessel fraction (BCVF), and degree of fibrosis – reticulin fiber density (RFD) – in sections from diagnostic BM biopsies from children diagnosed in Umeå, Uppsala, and Stockholm. RFD was also studied in BM sections from treatment day 29. Results: RFD had prognostic impact in patients with high-hyperdiploid (HeH) leukemia. Moreover, rapid reduction of RFD during induction treatment was associated with a favorable prognosis compared to slow reduction, in B-cell precursor (BCP) ALL patients. There was also a correlation between RFD at diagnosis and minimal residual disease (MRD) measured by flow cytometry on treatment day 29 in BCP patients. BCP patients with high RFD and high MVD had an unfavorable outcome compared to all other BCP patients. In addition, MVD and RFD were both associated with immunophenotype, and MVD with cytogenetic aberrations. There was a correlation between MVD and WBC count in BCP high-risk patients. There was also a strong correlation between BCVF and WBC count in all BCP patients, but not between BCVF and MVD or RFD. There was a negative correlation between MVD and in vitro cellular resistance to several drugs in BCP patients. A drug-resistance score combining the drugs most strongly correlated to MVD – cytarabine, doxorubicin, and dexametasone (ADD score) – identified the prognostic potential of ADD score in HeH patients with no unfavorable features. Conclusions: Taken together, these studies indicate that stroma factors in leukemia are related to both phenotypic and genotypic features of acute leukemia. Stroma factors also seem to influence the response to induction treatment, in vitro drug resistance, and outcome in certain subgroups of childhood ALL patients. The results emphasize the importance of BM stroma in leukemia and the need for greater use of BM biopsy at diagnosis