Polymorphisms in IL12A and cockroach allergy in children with asthma

Michael Pistiner¹^,3^,4 , Gary M Hunninghake¹^,2^,4 , Manuel E Soto-Quiros⁵ , Lydiana Avila⁵ , Amy Murphy¹^,4^,6 , Jessica Lasky-Su¹^,4^,6 , Brooke Schuemann¹ , Barbara J Klanderman¹^,4 , Benjamin A Raby¹^,2^,4 and Juan C Celedón¹^,2^,4

¹Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA

²Division of Pulmonary/Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA

³Division of Immunology, Children's Hospital, Boston, MA, USA

⁴Harvard Medical School, Boston, MA, USA

⁵Division of Pediatric Pulmonology, Hospital Nacional de Niños, San José, Costa Rica

⁶Dept. of Biostatistics, Harvard School of Public Health, Boston, MA, USA

author email corresponding author email

Clinical and Molecular Allergy 2008, 6:6doi:10.1186/1476-7961-6-6


Published:	31 July 2008

Abstract

Background

IL12A has been implicated in T-cell development and may thus influence the development of atopy and allergic diseases.

Methods

We tested for association between four linkage disequilibrium (LD)-tagging SNPs (rs2243123, rs2243151, rs668998, and rs17826053) in IL12A and asthma and allergy-related (serum total and allergen-specific IgE, and skin test reactivity [STR] to two common allergens) phenotypes in two samples: 417 Costa Rican children with asthma and their parents, and 470 families of 503 white children in the Childhood Asthma Management Program (CAMP). The analysis was conducted using the family-based association test (FBAT) statistic implemented in the PBAT program.

Results

Among Costa Rican children with asthma, homozygosity for the minor allele of each of two SNPs in IL12A (rs2243123 and rs2243151) was associated with increased risks of STR to American cockroach (P ≤ 0.03 for both SNPs), STR to German cockroach (P ≤ 0.01 for both SNPs), and having a positive IgE to German cockroach (P < 0.05 for both SNPs). Among children in CAMP, homozygosity for the minor allele of SNP rs2243151 in IL12A was inversely associated with STR to German cockroach (P = 0.03) and homozygosity for the minor allele of SNP rs17826053 in IL12A was associated with increased risks of STR to American cockroach (P = 0.01) and STR to German cockroach (P = 0.007). There was no significant association between any SNP in IL12A and asthma, STR to dust mite, or total IgE in Costa Rica or CAMP.

Conclusion

Our findings suggest that variants in IL12A influence cockroach allergy among children with asthma.