Objective:To investigate the association of IL-18 gene promoter SNPs with susceptibility to TB and its protein production in Chongqing Han children. Methods:Polymorphisms at -137 and -607 locus of IL-18 gene promoter in 113 TB child patients and 167 healthy controls were detected by SSP-PCR. The IL-18 productions in cultured supernatants of PBMCs from 46 healthy children were measured by ELISA. Results:The frequency of IL-18 -137GG genotype were significantly higher in TB patients(81.4%) than that in controls(67.7%)(P=0.01)

while the frequencies of -137GC genotype(1.8% vs 3.6%)and -137C allele(10.2% vs 18.0%) were conversely lower(P<0.05)

but the frequencies of alleles and genotypes at -607 were not statistically significant between the patients and the controls. Furthermore

-137GG genotype was significantly associated with lower IL-18 production compared with -137GC genotype when with or without PMA+A23187 stimulation for 24h. Conclusions:The results showed that IL-18 gene promoter polymorphisms at position -137 confer susceptibility to TB in Chongqing Han children.Subjects carrying -137G allele at the promoter of IL-18 gene

which is associated with lowered IL-18 level

may be a high risk population of TB development.