Familial aggregation of food allergy and sensitization to food allergens: a family-based study

• Published in: Clinical and experimental allergy Vol. 39; no. 1; pp. 101 - 109
• Main Authors: Tsai, H.-J., Kumar, R., Pongracic, J., Liu, X., Story, R., Yu, Y., Caruso, D., Costello, J., Schroeder, A., Fang, Y., Demirtas, H., Meyer, K. E., O'Gorman, M. R. G., Wang, X.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.2009; Blackwell
• Subjects: Adolescent; Adult; Allergens - administration & dosage; Allergens - adverse effects; Allergens - immunology; Allergic diseases; Animals; Arachis hypogaea; Biological and medical sciences; Cats; Child; Child, Preschool; Digestive allergic diseases; Dogs; familial aggregation; Family; Female; food allergy; Food Hypersensitivity - diagnosis; Food Hypersensitivity - epidemiology; Food Hypersensitivity - genetics; Food Hypersensitivity - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Genetic Predisposition to Disease; heritability; Humans; IgE mediated; Immunoglobulin E - blood; Immunopathology; Infant; Infant, Newborn; Interviews as Topic; Juglans; Male; Medical sciences; Prevalence; sensitization to food allergens; Surveys and Questionnaires; Triticum aestivum; Young Adult; Immunopathology; Food allergy; Food allergen; Family study; IgE; Familial aggregation; Immunology; sensitization to food allergens; Digestive diseases; Heritability; Sensitization; IgE mediated; Allergen
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/j.1365-2222.2008.03111.x

Summary Background The increasing prevalence of food allergy (FA) is a growing clinical and public health problem. The contribution of genetic factors to FA remains largely unknown. Objective This study examined the pattern of familial aggregation and the degree to which genetic factors contribute to FA and sensitization to food allergens. Methods This study included 581 nuclear families (2,004 subjects) as part of an ongoing FA study in Chicago, IL, USA. FA was defined by a set of criteria including timing, clinical symptoms obtained via standardized questionnaire interview and corroborative specific IgE cut‐offs for 95% positive predictive value (PPV) for food allergens measured by Phadia ImmunoCAP. Familial aggregation of FA as well as sensitization to food allergens was examined using generalized estimating equation (GEE) models, with adjustment for important covariates including age, gender, ethnicity and birth order. Heritability was estimated for food‐specific IgE measurements. Results FA in the index child was a significant and independent predictor of FA in other siblings (OR=2.6, 95% CI: 1.2–5.6, P=0.01). There were significant and positive associations among family members (father–offspring, mother–offspring, index–other siblings) for total IgE and specific IgE to all the nine major food allergens tested in this sample (sesame, peanut, wheat, milk, egg white, soy, walnut, shrimp and cod fish). The estimated heritability of food‐specific IgE ranged from 0.15 to 0.35 and was statistically significant for all the nine tested food allergens. Conclusion This family‐based study demonstrates strong familial aggregation of FA and sensitization to food allergens, especially, among siblings. The heritability estimates indicate that food‐specific IgE is likely influenced by both genetic and environmental factors. Together, this study provides strong evidence that both host genetic susceptibility and environmental factors determine the complex trait of IgE‐mediated FA.