Allergy, family history of autoimmune diseases, and the risk of multiple sclerosis.
OBJECTIVE
Previous reports suggested an association between allergy, autoimmunity, and risk of multiple sclerosis (MS), but results have been inconsistent. The present study assessed the association between history of allergy and autoimmune diseases, and the risk of MS.


METHODS
We conducted a case-control study nested in the Nurses' Health Study (NHS) and NHS II cohorts. A total of 298 women with MS were matched with 1248 healthy controls and 248 women with history of breast cancer. A mailed questionnaire gathered information about history of allergic conditions and autoimmune disorders.


RESULTS
History of allergy was not associated with MS risk [odds ratio (OR) 1.0, 95% confidence interval (CI) 0.8-1.4]. As expected, cases were more likely to have a positive family history of MS than controls (OR 9.7, 95% CI 6.1-15.3). A modest association was found between family history of other autoimmune diseases and MS risk (OR 1.4, 95% CI 1.0-1.8). We obtained similar results when we used women with breast cancer as comparison group.


CONCLUSIONS
Family history of other autoimmune diseases was associated with a higher MS risk, suggesting a common genetic background or shared environmental triggers. There was no clear association between personal history of allergy and risk of MS.
Alonso
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Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA. aalogut@alumni.unav.es
Hernán
M A
MA
Ascherio
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A
D000328:Adult; D001327:Autoimmune Diseases / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D001943:Breast Neoplasms; D016022:Case-Control Studies; D015897:Comorbidity; D004781:Environmental Exposure; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006306:Health Surveys; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D016015:Logistic Models; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires