title: Association between prediagnostic IgE levels and risk of glioma.
abstract: BACKGROUND
  Previous nested case-control studies suggest that a prediagnostic biomarker of allergy, IgE, is inversely associated with the risk of glioma, but these findings are inconsistent. The purpose of our study was to assess this association and determine how long before glioma diagnosis it may be observed.
  
  
  METHODS
  We conducted a nested case-control study using serum specimens from the Janus Serum Bank cohort in Norway. Blood donors who were subsequently diagnosed with glioma (n = 594 case subjects), between January 1, 1974 to December 31, 2007, were matched with subjects without glioma (n = 1177 control subjects) for date of blood collection, 2-year age interval at blood collection, and sex. Respiratory allergen-specific and total IgE levels in the serum were measured using fluorescent assays. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression models stratified on sex and glioblastoma, the most common glioma subtype. Data were stratified on time from blood collection to tumor diagnosis to assess how long before glioma diagnosis the association could be observed.
  
  
  RESULTS
  Among women, testing positive for allergen-specific IgE (>0.35 kU(A)/L) was associated with decreased risk of glioblastoma compared with testing negative (≤0.35 kU(A)/L; OR = 0.46, 95% CI = 0.23 to 0.93). Among both sexes combined, testing positive for total IgE (>100 kU/L) was associated with decreased risk of glioma compared with testing negative (≤100 kU/L; OR = 0.75, 95% CI = 0.56 to 0.99), and simultaneously testing positive for allergen-specific IgE and total IgE was associated with a borderline statistically significantly decreased risk of glioblastoma and glioma compared with simultaneously testing negative for these types of IgE. Testing positive for total IgE at least 20 years before diagnosis was associated with decreased risk of glioma compared with testing negative (OR = 0.54, 95% CI = 0.30 to 0.99).
  
  
  CONCLUSIONS
  An inverse association between IgE levels and risk of glioma was detected; the association was present at least 20 years before tumor diagnosis.
authors.affiliation: Division of Epidemiology, College of Public Health, The Ohio State University, Columbus, OH 43210, USA. jschwartzbaum@cph.osu.edu
authors.forename: Judith
authors.initials: J
authors.lastname: Schwartzbaum
authors.forename: Bo
authors.initials: B
authors.lastname: Ding
authors.forename: Tom Borge
authors.initials: TB
authors.lastname: Johannesen
authors.forename: Liv T N
authors.initials: LT
authors.lastname: Osnes
authors.forename: Linda
authors.initials: L
authors.lastname: Karavodin
authors.forename: Anders
authors.initials: A
authors.lastname: Ahlbom
authors.forename: Maria
authors.initials: M
authors.lastname: Feychting
authors.forename: Tom K
authors.initials: TK
authors.lastname: Grimsrud
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D016022:Case-Control Studies; D005260:Female; D005909:Glioblastoma / Q000453:epidemiology; D005910:Glioma / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D012107:Research Design; D012737:Sex Factors; D013997:Time Factors
chemical_list: D007073:Immunoglobulin E