Objective: Cathepsin S (CTSS) is a lysosomal cysteine protease and is predominantly expressed in antigen-presenting cells, which plays an important role in the allergic response. In this study, we explored the association between single nucleotide polymorphisms (SNPs) in the promotor regions in CTSS and risk of asthma.
Patients and methods: A total of 591 cases and 621 controls were recruited for this study. Five SNPs in the CTSS were selected including rs7534124, rs16827671, rs34495036, rs3754212, and rs1136774. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed for genotyping.
Results: Logistic regression analysis showed that rs7534124 CT and CT + CC genotypes had significantly decreased risk of asthma (CT vs.
Tt, or: 0.576, 95% CI: 0.425-0.780, p < 0.001; CT + CC vs.
Tt, or: 0.638, 95% CI: 0.479-0.849, p < 0.001; respectively) compared to TT genotype. Similarly, the rs1136774 AG and AG + GG genotypes (AG vs.
Aa, or: 0.581, 95% CI: 0.426-0.793, p = 0.001; AG + GG vs.
Aa, or: 0.647, 95% CI: 0.483-0.867, p = 0.004, respectively) were also associated with a decreased risk of asthma. However, there was no significant association between genotypes of the remaining SNPs and the risk of asthma (p > 0.006). Moreover, the alleles in all SNPs are also not associated with the risk of asthma.
Conclusions: Our study provided strong evidence that polymorphism of rs7534124 and rs1136774 in CTSS promoter may decrease the susceptibility of asthma in a Chinese Han population.