Allergy and risk of childhood leukaemia: results from the UKCCS.
We investigated the relationship between childhood leukaemia and preceding history of allergy. A nationwide case-control study of childhood cancers was conducted in the United Kingdom with population-based sampling of cases (n = 839) and controls (n = 1,337), matched on age, sex and region of residence. Information about clinically diagnosed allergies was obtained from primary care records. More than a third of subjects had at least one allergy diagnosed prior to leukaemia diagnosis (cases) or pseudo-diagnosis (controls). For both total acute lymphoblastic leukaemia (ALL) and common-ALL/precursor B-cell ALL (c-ALL), a history of eczema was associated with a 30% significant reduction in risk: the odds ratios (OR) and 95% confidence intervals (CI) were 0.70 (0.51-0.97) and 0.68 (0.48-0.98), respectively. Similar associations were observed for hayfever (OR = 0.47; 95% CI: 0.26-0.85 and OR = 0.62; 95% CI: 0.33-1.16 for ALL and c-ALL, respectively). No such patterns were seen either for asthma and ALL, or for any allergy and acute myeloid leukaemia. A comparative analysis of primary care records with parents recall of allergy revealed only moderate agreement with contemporaneous clinical diagnoses for both cases and controls--confirming the unreliability of parental report at interview. Our finding of a reciprocal relationship between allergy and ALL in children is compatible with the hypothesis that a dysregulated immune response is a critical determinant of childhood ALL.
Hughes
Ann M
AM
Epidemiology and Genetics Unit, Department of Health Sciences, University of York, York, United Kingdom.
Lightfoot
Tracy
T
Simpson
Jill
J
Ansell
Pat
P
McKinney
Patricia A
PA
Kinsey
Sally E
SE
Mitchell
Christopher D
CD
Eden
Tim O B
TO
Greaves
Mel
M
Roman
Eve
E
D000293:Adolescent; D001249:Asthma / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004485:Eczema / Q000453:epidemiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D007407:Interviews as Topic; D007938:Leukemia / Q000453:epidemiology*; D008297:Male; D008499:Medical Records; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology; D012307:Risk Factors