Venous Thromboembolism and Its Risk Factors in Children with Acute Lymphoblastic Leukemia in Israel: A Population-Based Study.

Venous thromboembolism (VTE) is a serious complication of acute lymphoblastic leukemia (ALL) therapy. The aim of this population-based study was to evaluate the rate, risk factors, and long-term sequelae of VTE in children treated for ALL. The cohort included 1191 children aged 1-19 years diagnosed with ALL between 2003-2018, prospectively enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. VTEs occurred in 89 patients (7.5%). Long-term sequelae were uncommon. By univariate analysis, we identified four significant risk factors for VTEs: Severe hypertriglyceridemia (p = 0.005), inherited thrombophilia (p < 0.001), age >10 years (p = 0.015), and high-risk ALL group (p = 0.039). In addition, the incidence of VTE was significantly higher in patients enrolled in AIEOP-BFM ALL 2009 than in those enrolled in ALL-IC BFM 2002 (p = 0.001). Severe VTE occurred in 24 children (2%), all of whom had at least one risk factor. Elevated triglyceride levels at diagnosis did not predict hypertriglyceridemia during therapy. In a multivariate analysis of 388 children, severe hypertriglyceridemia and inherited thrombophilia were independent risk factors for VTE. Routine evaluation for these risk factors in children treated for ALL may help identify candidates for intervention.

Influenza A/H1N1 in pediatric oncology patients.

BACKGROUND: Our aim was to determine the clinical and epidemiological features of pandemic influenza A/H1N1 in immunocompromised children with solid tumors and hematological malignancies. PATIENTS AND METHODS: A prospective study was conducted during the H1N1 pandemic between August 2009 and February 2010 in a pediatric hematology-oncology unit. Demographic and clinical data were obtained from all children with suspected H1N1 infection (high fever with or without respiratory symptoms). Laboratory diagnosis of influenza A/H1N1 was performed by means of polymerase chain reaction analysis of nasopharyngeal wash specimens. RESULTS: We identified 57 episodes of suspected influenza A/H1N1 infection in 40 children. In all episodes, children were treated with oseltamivir and antibiotics until influenza A/H1N1 results were received. Of all episodes, 13 (22.8%) tested positive for influenza A/H1N1. Two of the H1N1-positive children (15.4%) had been previously immunized against influenza A/H1N1. No differences between H1N1-positive and H1N1-negative children were noted in terms of demographic features, clinical presentation, laboratory findings, and underlying disease.Three polymerase chain reaction-positive (23.0%) children and 1 H1N1-negative (2.3%) child were admitted to the pediatric intensive care unit and were mechanically ventilated (P=0.03). One (7.7%) H1N1-positive patient died versus none of the H1N1-negative patients (P=0.2). The condition of all other children in both the groups improved rapidly during hospitalization. CONCLUSIONS: Febrile hospitalized pediatric oncology patients, with and without pandemic influenza A/H1N1, had a similar demographic and clinical presentation with a relatively good outcome. This was probably because of early antiviral treatment and possibly because of the relatively low virulence of the virus. Immunization should be encouraged in these patients.

Biochemical analysis and quantification of hematopoietic stem cells by infrared spectroscopy.

Identification of hematopoietic stem cells (HSCs) in different stages of maturation is one of the major issues in stem cell research and bone marrow (BM) transplantation. Each stage of maturation of HSCs is characterized by a series of distinct glycoproteins present on the cell plasma membrane surface, named a cluster of differentiation (CD). Currently, complicated and expensive procedures based on CD expression are needed for identification and isolation of HSCs. This method is under dispute, since the correct markers' composition is not strictly clear, thus there is need for a better method for stem cell characterization. In the present study, Fourier transform infrared (FTIR) spectroscopy is employed as a novel optical method for identification and characterization of HSCs based on their entire biochemical features. FTIR spectral analysis of isolated mice HSCs reveals several spectral markers related to lipids, nucleic acids, and carbohydrates, which distinguish HSCs from BM cells. The unique "open" conformation of HSC DNA as identified by FTIR is exploited for HSCs quantification in the BM. The proposed method of FTIR spectroscopy for HSC identification and quantification can contribute to stem cell research and BM transplantation.