The MLL recombinome of acute leukemias in 2017

Chromosomal rearrangements of the human MLL/KMT2A gene are associated with infant, pediatric, adult and therapy-induced acute leukemias. Here we present the data obtained from 2345 acute leukemia patients. Genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) were determined and 11 novel TPGs were identified. Thus, a total of 135 different MLL rearrangements have been identified so far, of which 94 TPGs are now characterized at the molecular level. In all, 35 out of these 94 TPGs occur recurrently, but only 9 specific gene fusions account for more than 90% of all illegitimate recombinations of the MLL gene. We observed an age-dependent breakpoint shift with breakpoints localizing within MLL intron 11 associated with acute lymphoblastic leukemia and younger patients, while breakpoints in MLL intron 9 predominate in AML or older patients. The molecular characterization of MLL breakpoints suggests different etiologies in the different age groups and allows the correlation of functional domains of the MLL gene with clinical outcome. This study provides a comprehensive analysis of the MLL recombinome in acute leukemia and demonstrates that the establishment of patient-specific chromosomal fusion sites allows the design of specific PCR primers for minimal residual disease analyses for all patients

Expression Patterns of Coagulation Factor XIII Subunit A on Leukemic Lymphoblasts Correlate with Clinical Outcome and Genetic Subtypes in Childhood B-cell Progenitor Acute Lymphoblastic Leukemia

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Molecular characterisation and clinical outcome of B-cell precursor acute lymphoblastic leukaemia with IG-MYC rearrangement

Rarely, immunophenotypically immature B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) carries an immunoglobulin-MYC rearrangement (IG-MYC-r). This can result in diagnostic confusion with Burkitt lymphoma/leukaemia and use of unproven individualised treatment schedules. Here we contrast the molecular characteristics of these conditions and investigate historic clinical outcome data. We identified 90 cases registered on a national BCP-ALL clinical trial/registry. Where present, diagnostic material underwent cytogenetic, exome, methylome and transcriptome analysis. Outcome was analysed to define 3-year event free survival (EFS) and overall survival (OS). IG-MYC-r was identified in diverse cytogenetic backgrounds, co-existing with either: established BCP-ALL specific abnormalities (high hyperdiploidy n=3, KMT2A-rearrangement n=6, iAMP21 n=1, BCR-ABL n=1); BCL2/BCL6-rearrangements (n=15); or, most commonly, as the only defining feature (n=64). Within this final group, precursor-like V(D)J breakpoints predominated (8/9) and KRAS mutations were common (5/11). DNA methylation identified a cluster of V(D)J rearranged cases, clearly distinct from Burkitt leukaemia/lymphoma. Children with IG-MYC-r within that subgroup had 3-year EFS of 47% and OS of 60%, representing a high-risk BCP-ALL. To develop effective management strategies this patient group must be allowed access to contemporary, minimal residual disease adapted, prospective clinical trial protocols

Effect of crocin on reducing the number of embryos and implantation sites in mice

Background: Crocin is one of the main components of saffron. The effect of saffron on birth abortion has been established. So, the possible effect of crocin on abortion was evaluated in this study. \ud Methods: Pregnant mice were divided into 8 groups. Each group received crocin (0 or 10 or 50 or 100 mg/kg, i.p.) from the first to the fifth day of pregnancy. Then, the first four groups were sacrificed on the seventh day to evaluate the implantation sites. The other four groups were sacrificed on the 20th day and the number of embryos was counted. Data were analyzed by ANOVA. \ud Results: Administration of crocin (50 and 100 mg/kg) significantly reduced the mean number of implantation sites and embryos compared to the control group (P<0.05).\ud Conclusion: Administration of high doses of crocin in the first week of pregnancy reduced the number of implantation places and embryos in mice

Copy Number Changes and Allele Distribution Patterns of Chromosome 21 in B Cell Precursor Acute Lymphoblastic Leukemia

Chromosome 21 is the most affected chromosome in childhood acute lymphoblastic leukemia. Many of its numerical and structural abnormalities define diagnostically and clinically important subgroups. To obtain an overview about their types and their approximate genetic subgroup-specific incidence and distribution, we performed cytogenetic, FISH and array analyses in a total of 578 ALL patients (including 26 with a constitutional trisomy 21). The latter is the preferred method to assess genome-wide large and fine-scale copy number abnormalities (CNA) together with their corresponding allele distribution patterns. We identified a total of 258 cases (49%) with chromosome 21-associated CNA, a number that is perhaps lower-than-expected because ETV6-RUNX1-positive cases (11%) were significantly underrepresented in this array-analyzed cohort. Our most interesting observations relate to hyperdiploid leukemias with tetra- and pentasomies of chromosome 21 that develop in constitutionally trisomic patients. Utilizing comparative short tandem repeat analyses, we were able to prove that switches in the array-derived allele patterns are in fact meiotic recombination sites, which only become evident in patients with inborn trisomies that result from a meiosis 1 error. The detailed analysis of such cases may eventually provide important clues about the respective maldistribution mechanisms and the operative relevance of chromosome 21-specific regions in hyperdiploid leukemias

SARS-CoV-2 in children with cancer or after haematopoietic stem cell transplant : An analysis of 131 patients

PURPOSE: There are limited data on SARS-CoV-2 (COVID-19) infection in children with cancer or after haematopoietic stem cell transplant (HSCT). We describe the severity and outcomes of SARS-COV-2 in these patients and identify factors associated with severe disease. METHODS: This was a multinational, observational study of children (aged <19 years) with cancer or HSCT and SARS-CoV-2 confirmed by polymerase chain reaction. COVID-19 was classified as asymptomatic, mild, moderate, severe or critical (≥1 organ support). Exact polytomous regression was used to determine the relationship between clinical variables and disease severity. RESULTS: One hundred and thirty-one patients with COVID-19 across 10 countries were identified (median age 8 years). Seventy-eight (60%) had leukaemia/lymphoma, 48 (37%) had solid tumour and five had primary immunodeficiency and HSCT. Fever (71%), cough (47%) and coryza (29%) were the most frequent symptoms. The median duration of detectable virus was 16 days (range, 1-79 days). Forty-nine patients (37%) were hospitalised for COVID-19 symptoms, and 15 (11%) required intensive care unit-level care. Chemotherapy was delayed/modified in 35% of patients. COVID-19 was asymptomatic in 32% of patients, mild in 47%, moderate in 8%, severe in 4% and critical in 9%. In 124 patients (95%), a full recovery was documented, and four (3%) died due to COVID-19. Any comorbidity (odds ratio, 2.94; 95% confidence interval [CI], 1.81-5.21), any coinfection (1.74; 95% CI 1.03-3.03) and severe baseline neutropenia (1.82; 95% CI 1.13-3.09) were independently and significantly associated with increasing disease severity. CONCLUSION: Although most children with cancer had asymptomatic/mild disease, 13% had severe COVID-19 and 3% died. Comorbidity, coinfection and neutropenia may increase the risk of severe disease. Our data may help management decisions in this vulnerable population

Recommendations for Diagnostics and Therapy of Children with Cancer Presenting with Fever and Neutropenia - Comparison of Two Current Guidelines

Immunocompromised children and adolescents receiving treatment for cancer have a considerably increased risk for infection. Neutropenia is the most important single risk factor for infectious complications, and fever in neutropenia is considered as an emergency. Whereas guidelines for the management of fever in neutropenic adults have been established for decades, specific pediatric guidelines have not been developed until recently. As children differ in many aspects from adults such as in the underlying malignancy or in the availability and dosing of antimicrobial compounds, guidelines for pediatric patients are important. This article reviews similarities and differences between the recently published German interdisciplinary guideline of the German Societies of Pediatric Infectious Diseases and Pediatric Oncology and Hematology and a guideline developed by a panel of international experts for the management of fever in neutropenia in children and adolescents