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Background and Objective: The etiology of childhood leukemia as the most common childhood malignancy remains largely unknown. This study was done to ascess the risk factors in childhood lymphoblastic leukemia in Shiraz-Iran. Materials and Methods: This case-control study was done on 141 children younger than 18 years suffering from acute lymphoblastic leukemia (ALL) whome resided at Fars Province of Iran during 2009. Patients were individually matched with 141 controls in respect to age, sex and residential area. Variables included: maternal age, parental education, father occupation, child birth weight and birth order, number of siblings, history of pet ownership including cat or dog, history of child day care attendance, history of leukemia in relatives, and history of mother diagnostic radiography during pregnancy. In order to evaluate the relationships between each variable and the risk of leukemia, odds ratio (OR) and 95% confidence interval (CI) were estimated using conditional logistic regression. Data were analyzed using SPSS-16 and Chi-Square test. Results: The agricultural occupation fathers in case and control were 17% and 5.7%, respectivley (P<0.01). The association between risk of childhood lymphoblastic leukemia with birth order≥3 (OR=5.939, 95% CI: 2.646-13.331, P<0.01), pet ownership (dog or cat) (OR=2.582, 95% CI: 1.265-5.269, P<0.009) and history of leukemia in first and second degree relatives (OR=3.5, 95% CI: 1.252-10.633, P<0.027) was significant. No relationship was found between birth weight, day care attendance, history of miscarriage, number of siblings and history of mother diagnostic radiology tests with risk of acute lymphoblastic leukemia. Conclusion: This study showed that father occupation, birth order, pet and history of leukemia in relation are risk factors of childhood acute lymphoblastic leukemia.

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Background and Objective: Varicella zoster virus (VZV) can cause a moderate disease in children, but with high risk of serious disease or death in children with acute lymphoblastic leukemia (ALL) Vaccination from infection can be safe, immunogenic, and effective in children with leukemia. This study was done to evaluate the IgG and IgM antibodies against VZV in children with acute lymphoblastic leukemia.

Methods: The descriptive-analytic study was performed on 66 children who were on chemotherapy in Dr Shigh hospital in Mashhad, Iran during 2012. Patients were receivied VZV vaccine. The title negative or positive serum sample for IgG-anti-VZV avidity was determined by using a test kit before and after injection of vaccines VZV for considering the efficacy of vaccines on pediatric patients.

Results: Title serum sample IgG were positive in 32.6% patients, these children have history of chicken pox disease and to be safe against of VZV. 78.3% of the patients were negative for IgG antibody and sensitive against of VZV.

Conclusion: Children with ALL receiving chemotherapy are sensitive to chicken pox disease according to negative IgG titer against VZV.