The role of the C-C chemokine receptor-5 Delta 32 polymorphism in asthma and in the production of regulated on activation, normal T cells expressed and secreted

Background: There are conflicting data regarding the role of a deletion in the C-C chemokine receptor-5 gene (CCR5*D32) in the pathogenesis of asthma and whether this deletion influences the production of regulated on activat ion, normal T cells expressed and secreted (RANTES). RANTES is a chemokine that is known to play an important role in the pathogenesis of allergic ast hma. Objective: We sought to determine whether CCR5*D32 is associated with incre ased RANTES production, the presence of asthma, and the severity of asthma. Methods: A PCR assay for CCR5*D32 was developed. The prevalence of CCR5*D32 was determined in a group of patients with mild-to-moderate asthma, a grou p of subjects with severe asthma who had fatal or near-fatal asthma attacks , and a group of nonasthmatic control subjects. The level of RANTES produce d by stimulated and unstimulated T cells was measured by using a commercial ly available immunoassay. Results: The frequency of CCR5*D32 was not significantly increased in the s evere asthma group compared with in the mild-to-moderate asthma group. CCR5 *D32 was not increased in the asthmatic subjects versus in the control subj ects. There was no significant increase in RANTES levels from T cells heter ozygous for CCR5*D32 compared with wild-type cells. Conclusion: These data indicate that the CCR5*D32 allele is not a genetic r isk factor for the development of asthma and does not influence disease sev erity. The CCR5*D32 allele does not influence RANTES production in the hete rozygous state.