MicroRNA-155-5p Plays a Critical Role in Transient Leukemia of Down Syndrome by Targeting Tumor Necrosis Factor Receptor Superfamily Members.

BACKGROUND/AIMS: Down syndrome associated disorders are caused by a complex genetic context where trisomy 21 is a central component in relation to other changes involving epigenetic regulators and signaling molecules. This unique genetic context is responsible for the predisposition of people with Down syndrome to acute leukemia. Although, the research in this field has discovered some important pathogenic keys, the exact mechanism of this predisposition is not known. METHODS: In this study we applied functional enrichment analysis to evaluate the interactions between genes localized on chromosome 21, genes already identify as having a key role in acute leukemia of Down syndrome, miRNAs and signaling pathways implicated in cancer and cell development and found that miR-155 has a high impact in genes present on chromosome 21. Forward, we performed next generation sequencing on DNA samples from a cohort of patients diagnosed with acute leukemia of Down syndrome and in vitro functional assay using a CMK-86 cell line, transfected with either mimic or inhibitor of the microRNA-155-5p. RESULTS: Our results show that the epigenetic alteration of the TNF superfamily receptors in Down syndrome, which can be correlated to microRNA-155-5p aberrant activity, may play an important role in cell signaling and thus be linked to acute myeloid leukemia. CONCLUSION: Some genes, already shown to be mutated in AML-DS, are potential targets for miR-155. Our results show that the epigenetic alteration of the TNF superfamily receptors in Down syndrome may play an important role in cell signaling and thus be linked to acute myeloid leukemia.

Transient leukemia of Down syndrome.

Childhood leukemia is mostly a "developmental accident" during fetal hematopoiesis and may require multiple prenatal and postnatal "hits". The World Health Organization defines transient leukemia of Down syndrome (DS) as increased peripheral blood blasts in neonates with DS and classifies this type of leukemia as a separate entity. Although it was shown that DS predisposes children to myeloid leukemia, neither the nature of the predisposition nor the associated genetic lesions have been defined. Acute myeloid leukemia of DS is a unique disease characterized by a long pre-leukemic, myelodysplastic phase, unusual chromosomal findings and a high cure rate. In the present manuscript, we present a comprehensive review of the literature about clinical and biological findings of transient leukemia of DS (TL-DS) and link them with the genetic discoveries in the field. We address the manuscript to the pediatric generalist and especially to the next generation of pediatric hematologists.

Breath Prints for Diagnosing Asthma in Children.

Electronic nose (e-nose) is a new technology applied for the identification of volatile organic compounds (VOC) in breath air. Measuring VOC in exhaled breath can adequately identify airway inflammation, especially in asthma. Its noninvasive character makes e-nose an attractive technology applicable in pediatrics. We hypothesized that an electronic nose could discriminate the breath prints of patients with asthma from controls. A cross-sectional study was conducted and included 35 pediatric patients. Eleven cases and seven controls formed the two training models (models A and B). Another nine cases and eight controls formed the external validation group. Exhaled breath samples were analyzed using Cyranose 320, Smith Detections, Pasadena, CA, USA. The discriminative ability of breath prints was investigated by principal component analysis (PCA) and canonical discriminative analysis (CDA). Cross-validation accuracy (CVA) was calculated. For the external validation step, accuracy, sensitivity and specificity were calculated. Duplicate sampling of exhaled breath was obtained for ten patients. E-nose was able to discriminate between the controls and asthmatic patient group with a CVA of 63.63% and an M-distance of 3.13 for model A and a CVA of 90% and an M-distance of 5.55 for model B in the internal validation step. In the second step of external validation, accuracy, sensitivity and specificity were 64%, 77% and 50%, respectively, for model A, and 58%, 66% and 50%, respectively, for model B. Between paired breath sample fingerprints, there were no significant differences. An electronic nose can discriminate pediatric patients with asthma from controls, but the accuracy obtained in the external validation was lower than the CVA obtained in the internal validation step.

SERS-Based Evaluation of the DNA Methylation Pattern Associated With Progression in Clonal Leukemogenesis of Down Syndrome.

Here we show that surface-enhanced Raman scattering (SERS) analysis captures the relative hypomethylation of DNA from patients with acute leukemia associated with Down syndrome (AL-DS) compared with patients diagnosed with transient leukemia associated with Down syndrome (TL-DS), an information inferred from the area under the SERS band at 1005 cm-1 attributed to 5-methycytosine. The receiver operating characteristic (ROC) analysis of the area under the SERS band at 1005 cm-1 yielded an area under the curve (AUC) of 0.77 in differentiating between the AL-DS and TL-DS groups. In addition, we showed that DNA from patients with non-DS myeloproliferative neoplasm (non-DS-MPN) is hypomethylated compared to non-DS-AL, the area under the SERS band at 1005 cm-1 yielding an AUC of 0.78 in separating between non-DS-MPN and non-DS-AL. Overall, in this study, the area of the 1005 cm-1 DNA SERS marker band shows a stepwise decrease in DNA global methylation as cells progress from a pre-leukemia to a full-blown acute leukemia, highlighting thus the potential of SERS as an emerging method of analyzing the methylation landscape of DNA in the context of leukemia genesis and progression.

A narrative review of central nervous system involvement in acute leukemias.

Acute leukemias (both myeloid and lymphoblastic) are a group of diseases for which each year more successful therapies are implemented. However, in a subset of cases the overall survival (OS) is still exceptionally low due to the infiltration of leukemic cells in the central nervous system (CNS) and the subsequent formation of brain tumors. The CNS involvement is more common in acute lymphocytic leukemia (ALL), than in adult acute myeloid leukemia (AML), although the rates for the second case might be underestimated. The main reasons for CNS invasion are related to the expression of specific adhesion molecules (VLA-4, ICAM-1, VCAM, L-selectin, PECAM-1, CD18, LFA-1, CD58, CD44, CXCL12) by a subpopulation of leukemic cells, called "sticky cells" which have the ability to interact and adhere to endothelial cells. Moreover, the microenvironment becomes hypoxic and together with secretion of VEGF-A by ALL or AML cells the permeability of vasculature in the bone marrow increases, coupled with the disruption of blood brain barrier. There is a single subpopulation of leukemia cells, called leukemia stem cells (LSCs) that is able to resist in the new microenvironment due to its high adaptability. The LCSs enter into the arachnoid, migrate, and intensively proliferate in cerebrospinal fluid (CSF) and consequently infiltrate perivascular spaces and brain parenchyma. Moreover, the CNS is an immune privileged site that also protects leukemic cells from chemotherapy. CD56/NCAM is the most important surface molecule often overexpressed by leukemic stem cells that offers them the ability to infiltrate in the CNS. Although asymptomatic or with unspecific symptoms, CNS leukemia should be assessed in both AML/ALL patients, through a combination of flow cytometry and cytological analysis of CSF. Intrathecal therapy (ITT) is a preventive measure for CNS involvement in AML and ALL, still much research is needed in finding the appropriate target that would dramatically lower CNS involvement in acute leukemia.

Baseline characteristics of a nationwide cohort of pediatric patients with acute leukemias of Down syndrome.

PURPOSE: Down syndrome (DS) or trisomy 21, brings together some unique aspects from clinical pediatrics. Among the hematological disorders present in DS, by far the most important is the predisposition for developing acute leukemia. Acute myeloid leukemia (AML) of DS has a preleukemic state with the onset in the neonatal period, rarely symptomatic but with the presence of blasts in peripheral blood smear and apparently a spontaneous remission. The unique tumor profile of DS underlines the importance of chromosome 21 in hematopoiesis and it can help understanding leukemogenesis in general. The purpose of this study was to present the very rare cases with DS and transient leukemia and/or acute leukemia that were found in a nationwide survey of Romania, in three centers of pediatric hematology and oncology. METHODS: A nationwide analysis of the very rare cases of transient leukemia of DS are described, involving the three major pediatric hematology centers of Romania: Cluj Napoca, Bucharest and Timisoara. Data analysis was performed using R 3.5.3. Categorical variables were presented as absolute value (percent). Contingency tables were analyzed using the Fisher test. Normality of the distribution was assessed using the Shapiro test and histogram visualization, but also took into consideration the sample size. Non-normally distributed variables were presented as median (quartile 1, quartile 3). Wilcoxon test was used to determine the differences between two non-normally distributed groups. A p value under 0.05 was considered statistically significant. RESULTS: It appears that the more aggressive entity at presentation is represented by CD45 positive leukemia, which is the more frequent of the myeloid lineage and has lower counts at diagnosis. CONCLUSION: We address this manuscript to pediatricians and neonatologists in order to emphasize the importance of diagnosing hematological disorders in children with DS, especially neonates, even if they are asymptomatic.

The Influence of Methylating Mutations on Acute Myeloid Leukemia: Preliminary Analysis on 56 Patients.

Acute myeloid leukemia (AML) is a hematologic malignancy characterized by abnormal proliferation and a lack of differentiation of myeloid blasts. Considering the dismal prognosis this disease presents, several efforts have been made to better classify it and offer a tailored treatment to each subtype. This has been formally done by the World Health Organization (WHO) with the AML classification schemes from 2008 and 2016. Nonetheless, there are still mutations that are not currently included in the WHO AML classification, as in the case of some mutations that influence methylation. In this regard, the present study aimed to determine if some of the mutations that influence DNA methylation can be clustered together regarding methylation, expression, and clinical profile. Data from the TCGA LAML cohort were downloaded via cBioPortal. The analysis was performed using R 3.5.2, and the necessary packages for classical statistics, dimensionality reduction, and machine learning. We included only patients that presented mutations in DNMT3A, TET2, IDH1/2, ASXL1, WT1, and KMT2A. Afterwards, mutations that were present in too few patients were removed from the analysis, thus including a total of 57 AML patients. We observed that regarding expression, methylation, and clinical profile, patients with mutated TET2, IDH1/2, and WT1 presented a high degree of similarity, indicating the equivalence that these mutations present between themselves. Nonetheless, we did not observe this similarity between DNMT3A- and KMT2A-mutated AML. Moreover, when comparing the hypermethylating group with the hypomethylating one, we also observed important differences regarding expression, methylation, and clinical profile. In the current manuscript we offer additional arguments for the similarity of the studied hypermethylating mutations and suggest that those should be clustered together in further classifications. The hypermethylating and hypomethylating groups formed above were shown to be different from each other considering overall survival, methylation profile, expression profile, and clinical characteristics. In this manuscript, we present additional arguments for the similarity of the effect generated by TET2, IDH1/2, and WT1 mutations in AML patients. Thus, we hypothesize that hypermethylating mutations skew the AML cells to a similar phenotype with a possible sensitivity to hypermethylating agents.

Approach to the Adult Acute Lymphoblastic Leukemia Patient.

During recent decades, understanding of the molecular mechanisms of acute lymphoblastic leukemia (ALL) has improved considerably, resulting in better risk stratification of patients and increased survival rates. Age, white blood cell count (WBC), and specific genetic abnormalities are the most important factors that define risk groups for ALL. State-of-the-art diagnosis of ALL requires cytological and cytogenetical analyses, as well as flow cytometry and high-throughput sequencing assays. An important aspect in the diagnostic characterization of patients with ALL is the identification of the Philadelphia (Ph) chromosome, which warrants the addition of tyrosine kinase inhibitors (TKI) to the chemotherapy backbone. Data that support the benefit of hematopoietic stem cell transplantation (HSCT) in high risk patient subsets or in late relapse patients are still questioned and have yet to be determined conclusive. This article presents the newly published data in ALL workup and treatment, putting it into perspective for the attending physician in hematology and oncology.

Antibiotic treatment in childhood community-acquired pneumonia - clinical practice versus guidelines: results from two university hospitals.

BACKGROUND AND AIMS: Community-acquired pneumonia (CAP) is a both common and serious childhood infection. Antibiotic treatment guidelines help to reduce inadequate antibiotics prescriptions. METHODS: We conducted a retrospective study at the Clinical Emergency Hospital for Children, 3rd Pediatric Clinic, Cluj-Napoca and Dr. Gavril Curteanu Clinical City Hospital, in Oradea. All patients discharged with a diagnosis of CAP between December 1, 2014 and February 28, 2015, were included in the study. RESULTS: There were 146 cases discharged with pneumonia in Cluj-Napoca center (mean age 4 years; range: 1 month - 16 years), and 212 cases in Oradea center (mean age 0.9 years; range: 2 weeks - 8 years). All cases were analyzed. The analysis made in Clinical Emergency Hospital for Children, 3rd Pediatric Clinic, Cluj-Napoca, showed that the antibiotics used in children hospitalized with community-acquired CAP are cefuroxime (43%), ceftriaxone (23%), macrolides (16%), ampicillin in association with an aminoglycoside (6%) and other antibiotics. The same antibiotics were used in Dr. Gavril Curteanu Clinical City Hospital of Oradea, where ampicillin in association with aminoglycoside was utilized in younger children (mean age 1.3 years), while ceftriaxone in older children (5.7 years) and children with high inflammation markers (ESR, CRP). From 11 pleurisy cases, 9 received cefuroxime or ceftriaxone. CONCLUSIONS: There was a wide variability in CAP antibiotic treatment across university hospitals, regarding antibiotic choice and dosing. Antibiotic selection was not always related to the clinical and laboratory characteristics of the patient. The national guideline was not followed, especially in children aged one to three months.

Performance of lung ultrasonography for the diagnosis of communityacquired pneumonia in hospitalized children.

AIMS: The objective of the study was to assess the performance of lung ultrasonography (LUS) as compared to chest radiography and the clinical criteria for the diagnosis of pneumonia in children. MATERIALS AND METHODS: This was a retrospective study in which data were collected from medical files of 81 children admitted with a clinical suspicion of pneumonia in which both an LUS and a chest radiograph during the hospitalization were performed. Reference standard used for the diagnosis of pneumonia were chest radiographs (consolidation, parenchymal infiltrates, and interstitial infiltrate) and clinical criteria. LUSfindings were reported as normal, parenchymal consolidations and pleural effusions. RESULTS: Radiological pneumonia was reported in 72 of the 81 patients (88.9%). LUS identified parenchymal consolidations in 62 cases. LUS correctly identified radiological pneumonia with a sensitivity of 79.2% and a specificity of 44.4%. The positive predictive value (PPV) was 91.9% and the negative predictive value (NPV) was 21.0%. When clinical criteria were used as reference standard, the sensitivity, specificity, PPV and NPV of correctly identifying clinical pneumonia cases by LUS (only consolidations) were 80.0%, 66.7%, 96.8% and 21.0%. When indicative for the presence of pneumonia either the ultrasound consolidation or the ultrasound detected pleural effusion were considered when the sensitivity, PPV and NPV increased to 96.0% (95%CI: 88.8-99.2), 97.3% (95%CI: 92.0-99.1), and 57.1% (95%CI: 27.7-82.2), respectively. CONCLUSIONS: In our opinion, our findings together withprevious ones available in the literature recommend LUS as a valuable investigation for the diagnosis of community-acquiredpneumonia in children.

Autoimmune hepatitis with sclerosing cholangitis in a patient with thiopurine methyltransferase deficiency: case presentation.

The association between two autoimmune diseases is known in the literature as overlap syndrome. We present the case of an 18-year-old boy, diagnosed at the age of 13 with an overlap syndrome between type I autoimmune hepatitis and sclerosing cholangitis. The response to immunosuppressant therapy was hampered by azathioprine-induced toxicity causing severe pancytopenia, as a result of thiopurine methyltransferase enzyme genetic deficiency. Treatment was replaced by mycophenolate mofetil. Although the relapse rate was reduced, the disease progressed to cirrhosis. Specific features of this case were the overlap syndrome, young age of onset, especially for sclerosing cholangitis, azathioprine toxicity that influenced the prognosis and the treatment problems regarding the use and efficiency of alternative immunosuppressant agents in pediatric patients.

Effects of prophylactic ibuprofen and paracetamol administration on the immunogenicity and reactogenicity of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugated vaccine (PHiD-CV) co-administered with DTPa-combined vaccines in children: An open-label, randomized, controlled, non-inferiority trial.

Prophylactic paracetamol administration impacts vaccine immune response; this study ( www.clinicaltrials.gov : NCT01235949) is the first to assess PHiD-CV immunogenicity following prophylactic ibuprofen administration. In this phase IV, multicenter, open-label, randomized, controlled, non-inferiority study in Romania (November 2010-December 2012), healthy infants were randomized 3:3:3:1:1:1 to prophylactically receive immediate, delayed or no ibuprofen (IIBU, DIBU, NIBU) or paracetamol (IPARA, DPARA, NPARA) after each of 3 primary doses (PHiD-CV at age 3/4/5 months co-administered with DTPa-HBV-IPV/Hib at 3/5 and DTPa-IPV/Hib at 4 months) or booster dose (PHiD-CV and DTPa-HBV-IPV/Hib; 12-15 months). Non-inferiority of immune response one month post-primary vaccination in terms of percentage of infants with anti-pneumococcal antibody concentrations ≥0.2 µg/mL (primary objective) was demonstrated if the upper limit (UL) of the 98.25% confidence interval of difference between groups (NIBU vs IIBU, NIBU vs DIBU) was <10% for ≥7/10 serotypes. Immunogenicity and reactogenicity/safety were evaluated, including confirmatory analysis of difference in fever incidences post-primary vaccination in IBU or DIBU group compared to NIBU. Of 850 infants randomized, 812 were included in the total vaccinated cohort. Non-inferiority was demonstrated for both comparisons (UL was <10% for 9/10 vaccine serotypes; exceptions: 6B [NIBU], 23F [IIBU]). However, fever incidence post-primary vaccination in the IIBU and DIBU groups did not indicate a statistically significant reduction. Prophylactic administration (immediate or delayed) of paracetamol decreased fever incidence but seemed to reduce immune response to PHiD-CV, except when given only at booster. Twenty-seven serious adverse events were reported for 15 children; all resolved and were not vaccination-related.