Association between regulated upon activation, normal T cells expressed and secreted (RANTES) -28C/G polymorphism and asthma risk--a meta-analysis.

Regulated upon activation, normal T-cell expressed and secreted (RANTES) is one of the most extensively studied C-C chemokines in allergic inflammation. A growing body of evidence suggests that many cell types present in asthmatic airways have the capacity to generate RANTES, which directly supported the potential role of RANTES in asthma. A number of studies have evaluated the functional polymorphism -28C/G in the RANTES promoter region, which had been found to affect the transcription of the RANTES gene, in relation to asthma susceptibility. However, the results remain conflicting rather than conclusive. This meta-analysis on 1894 asthma cases and 1766 controls for -28C/G from 9 published case-control studies showed that the variant allele -28G was associated with significantly increased risk of asthma (GG+CG vs CC: OR=1.24, 95%CI=1.08-1.41) without any between-study heterogeneity.In the stratified analysis by asthma type, age and ethnicity, we found that the increased asthma risk associated with -28G/C polymorphism was more evident in children (OR=1.24, 95%CI=1.06-1.45), Asian group (OR=1.27, 95%CI=1.04-1.56) and African group (OR=1.72, 95%CI=1.07-2.78). These results suggest that RANTES -28G/C polymorphism may contribute to asthma development, especially in children and in Asian population. Additional well-designed large studies were required for the validation of this association.