title: Childhood leukaemia and infectious exposure: a report from the United Kingdom Childhood Cancer Study (UKCCS).
abstract: Data from a national case-control study are used to explore the relationships between childhood leukaemia, infant infection and three markers of infectious exposure - birth order, infant-activity group attendance and area-based deprivation. Amongst controls, clinically diagnosed infection in the first year varied little with birth order and infant-activity group attendance - with 4 in 5 children having at least one infection, and each child averaging around 2.9 (2.8-3.0). Amongst cases of acute lymphoblastic leukaemia (ALL), the levels of infection increased as the indices of infectious exposure increased - for example, odds ratios associated with at least one infection in the first year being 0.9 (95% confidence interval (CI): 0.6-1.4) for birth order one and 1.6 (95% CI: 1.1-2.2) for birth order two or more. By contrast, interview data were misleading, with mothers - particularly case mothers - consistently under-reporting. We conclude that the findings based on clinical data, combined with the markers of infectious exposure, confirm the observation that immune dysregulation among children who develop ALL is detectable from an early age.
authors.affiliation: Department of Health Sciences, University of York, YO10 5DD, UK. jill.simpson@egu.york.ac.uk
authors.forename: Jill
authors.initials: J
authors.lastname: Simpson
authors.forename: Alex
authors.initials: A
authors.lastname: Smith
authors.forename: Pat
authors.initials: P
authors.lastname: Ansell
authors.forename: Eve
authors.initials: E
authors.lastname: Roman
mesh_terms: D001722:Birth Order; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007938:Leukemia / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D012307:Risk Factors; D012959:Socioeconomic Factors; D006113:United Kingdom / Q000453:epidemiology