Abstract: Objective  To provide a quantitative summary in estimating the association between the polymorphisms of two loci in interleukin-18 (IL-18) gene promoter and susceptibility of tuberculosis by Meta-analysis. Methods  The polymorphisms of IL-18 promoter gene -137 G/C and -607 C/A were analyzed using the sequence specificity primer polymerase chain reaction (PCR-SSP) and gene sequencing analysis. Based on the strict quality evaluation, statistics was carried out for Meta analysis by Review Manager 5.0 software. Inclusion criteria were as follow: (1) the studies on the association between the polymorphisms of IL-18 promoter gene -137 G/C and -607 C/A and the tuberculosis susceptibility; (2) the gene distribution of the control group coincides to the law of genetic equilibrium of HardyWeinberg; (3) the original material was complete; (4) the study provided the genotype frequency or allele frequency; (5) the study was published in Chinese or English; (6) the polymorphisms were detected by PCR-SSP and gene sequencing or SNaPshot SNP technology. Exclusions criteria were as follow: (1) the repeated report; (2) the data were not clear; (3) the study was based on the family; (4) the gene distribution of the control group was not inspected by the law of H-W genetic equilibrium. Results  According the established inclusion criteria，6 studies with a total of 695 cases and 879 controls were identified in the SNP -607 C/A of the promoter of IL-18 gene. The SNP -137 G/C was identified in 5 studies which contained 594 cases and 781 controls. The pooled odds ratios (ORs) for studies with -137 C and -607 A loci allele variants in the IL-18 promoter gene were 1.41（95% CI: 1.15～1.74，P=0.001）and 0.93（95% CI为0.81～1.08，P=0.36），respectively，compared with -137 G and -607 C alleles．Conclusion  SNP -137G/C located in IL-18 promoter was associated with tuberculosis, and may be one of the susceptibility loci of tuberculosis. The association of SNP -607 C/A and tuberculosis susceptibility showed no statistically significant difference in our study.

Key words: Tuberculosis, Interleukin-18, Polymorphism,single necleotide, Meta analysis