title: Atopic disease and childhood acute lymphoblastic leukemia.
abstract: Our objective was to test the hypothesis that the risk of childhood leukemia is associated with allergies or a family history of allergy. We used a German population-based case-control study with self-reported information on allergies of the children and their first-degree relatives. Our study included a total of 1,130 cases of acute lymphoblastic leukemia (ALL), 164 cases of acute myeloid leukemia (AML) and 2,957 controls. A major finding of our study is that hay fever, neurodermatitis and contact eczema are underrepresented within the group of children with ALL, with respective odds ratios (OR) of 0.45 (95% confidence interval [CI] 0.31-0.66) for hay fever, of 0.49 (CI 0.34-0.71) for neurodermatitis and of 0.62 (CI 0.39-0.99) for eczema, respectively. Atopic diseases, comprising hay fever, neurodermatitis and asthma, are much stronger related with a reduced risk of ALL than other allergies (OR 0.52, CI 0.40-0.67 vs. OR 0.89, CI 0.66-1.21). The strongest association is seen with an atopy in the index child; however, ALL risk is also reduced if one of the parents or a sibling had an atopic disease. No such consistent pattern is seen for AML. Our data suggest that atopy or a family history of atopy are associated with a reduced risk of childhood ALL. Recall bias remains a concern, but sensitivity analysis provided some evidence that the protective effect is unlikely to be attributable to this bias in its entirety.
authors.affiliation: Institute for Medical Biostatistics, Epidemiology and Informatics, University of Mainz, Mainz, Germany. schuez@imbei.uni-mainz.de
authors.forename: Joachim
authors.initials: J
authors.lastname: Schüz
authors.forename: Gareth
authors.initials: G
authors.lastname: Morgan
authors.forename: Eva
authors.initials: E
authors.lastname: Böhler
authors.forename: Peter
authors.initials: P
authors.lastname: Kaatsch
authors.forename: Jörg
authors.initials: J
authors.lastname: Michaelis
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004485:Eczema / Q000150:complications / Q000453:epidemiology; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications* / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009450:Neurodermatitis / Q000150:complications / Q000453:epidemiology; D016017:Odds Ratio; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology* / Q000209:etiology; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000453:epidemiology; D012307:Risk Factors; D012923:Social Class