title: Association of atopic diseases and parvovirus B19 with acute lymphoblastic leukemia in childhood and adolescence in the northeast of Brazil.
abstract: BACKGROUND
  Several factors related to the immune system, such as a history of allergies and virus infections, may be associated with acute lymphoblastic leukemia (ALL). The purpose of this study was to analyze whether the presence of atopic diseases and previous infection with parvovirus B19 and Epstein-Barr virus (EBV) are associated with the development of ALL.
  
  
  METHODS
  This case-control study was performed in two tertiary hospitals located in northeastern Brazil. The study population included 60 patients who were diagnosed with non-T-cell ALL using myelogram and immunophenotyping and 120 patients in the control group. Atopy was evaluated via a parent questionnaire and medical records. Total immunoglobulin (Ig)E and IgG levels of parvovirus B19 and EBV were measured in the serum. Logistic regression was performed to assess the association between variables and odds of ALL.
  
  
  RESULTS
  We identified a significant inverse association between rhinitis, urticaria and elevated IgE serum levels with ALL. A history of parvovirus B19 infection showed a significant association with this type of cancer [OR (95 % CI) 2.00 (1.94-4.26); P = 0.050]. In logistic regression, the presence of atopy was a protective factor [OR (95 % CI) 0.57 (0.38-0.83); P = 0.004], and the presence of IgG for parvovirus B19 was an important risk factor for ALL [OR (95 % CI) 2.20 (1.02-4.76); P = 0.043].
  
  
  CONCLUSIONS
  These results suggest that atopic diseases and elevated total IgE levels are associated with a potential protective effect on the development of ALL. Previous infection with parvovirus B19 contributed to ALL susceptibility.
authors.affiliation: Department of Genetics and Pediatrics, Federal University of Paraíba, João Pessoa, PB, Brazil.
authors.forename: Joacilda
authors.initials: J
authors.lastname: da Conceição Nunes
authors.affiliation: Research Center for Allergy and Clinical Immunology, Federal University of Pernambuco, Av. Prof. Moraes Rêgo, s/n, University City, Recife, PE, CEP 50670-901, Brazil. georgiaveras@uol.com.br.
authors.forename: Georgia Véras
authors.initials: GV
authors.lastname: de Araujo
authors.affiliation: Department of Biostatistics in Science of Health, Federal University of Pernambuco, Recife, PE, Brazil.
authors.forename: Marcelo Tavares
authors.initials: MT
authors.lastname: Viana
authors.affiliation: Research Center for Allergy and Clinical Immunology, Federal University of Pernambuco, Av. Prof. Moraes Rêgo, s/n, University City, Recife, PE, CEP 50670-901, Brazil.|Department of Pediatrics, Federal University of Pernambuco, Recife, PE, Brazil.
authors.forename: Emanuel Sávio Cavalcanti
authors.initials: ES
authors.lastname: Sarinho
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D010322:Parvoviridae Infections / Q000453:epidemiology* / Q000821:virology; D016732:Parvovirus B19, Human / Q000276:immunology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology*; D065840:Protective Factors; D065631:Rhinitis, Allergic / Q000453:epidemiology*; D012307:Risk Factors; D014581:Urticaria / Q000453:epidemiology*
chemical_list: D007074:Immunoglobulin G; D007073:Immunoglobulin E
keywords: Acute lymphoblastic leukemia; Atopic disease; Epstein−Barr virus; IgE-mediated allergy; Parvovirus B19 with ALL; Pediatrics