Racial differences in the association of CD14 polymorphisms with serum total IgE levels and allergen skin test reactivity

ZongYao Wang,¹ John S Sundy,¹ Catherine M Foss,¹ Huiman X Barnhart,² Scott M Palmer,¹ Sallie D Allgood,³ Evan Trudeau,¹ Katie M Alexander,³ Marc C Levesque<sup>3

1</sup>Division of Pulmonary, Allergy and Critical Care Medicine, ²Duke Clinical Research Institute, ³Division of Rheumatology and Immunology, Duke University Medical Center, Durham, NC, USA

Background: The CD14 C-159T single nucleotide polymorphism (SNP) has been investigated widely as a candidate genetic locus in patients with allergic disease. There are conflicting results for the association of the CD14 C-159T SNP with total serum immunoglobulin E (IgE) levels and atopy. There are limited data regarding the association of the CD14 C-159T SNP in subjects of African ancestry. The aim of the study was to determine whether the C-159T SNP and other CD14 SNPs (C1188G, C1341T) were associated with total serum IgE levels and with allergy skin test results in nonatopic and atopic subjects; as well as in Caucasian and African American subjects.
Methods: A total of 291 participants, 18–40 years old, were screened to determine whether they were atopic and/or asthmatic. Analyses were performed to determine the association between CD14 C-159T, C1188G, or C1341T genotypes with serum IgE levels and with the number of positive skin tests among Caucasian or African American subjects.
Results: We found no significant association of serum total IgE level with CD14 C-159T, C1188G, or C1341T genotypes within nonatopic or atopic subjects. Subjects with CD14-159 T alleles had significantly more positive allergen skin tests than subjects without CD14-159 T alleles (P = 0.0388). There was a significant association between the CD14 1188 G allele, but not the CD14 1341 T allele, with the number of positive skin-test results in Caucasians, but not in African Americans.
Conclusion: These results support a possible association between CD14 polymorphisms and atopy. CD14-159 T or CD14 1188 G alleles were associated with atopic disease. For subjects with CD14 1188 G alleles, the association with atopic disease was stronger in Caucasians compared to African Americans.

Keywords: total serum immunoglobulin E, IgE, skin prick test, SPT, CD14-159T, single nucleotide polymorphism, SNP, lipopolysaccharide, LPS, endotoxin