Background. The factors that predispose to pulmonary tuberculosis (PTB) are not fully understood. Previous studies have shown that cytokine gene polymorphisms were associated with PTB.Objectives. In this study, we have investigated the relationship betweenILB,IL6,andTNFαpolymorphisms and a predisposition toMycobacterium tuberculosis(MTB) infection and PTB.Methods. A total of 209 cases of PTB, 201 subjects with latent TB infection (LTBI), and 204 healthy controls (HCS) were included in this study. Logistic regression analyses under allelic, homozygous, and heterozygous models were used to calculatePvalues, odds ratios (ORs), and 95% confidence intervals (CIs) for assessing the association between single nucleotide polymorphisms (SNPs) and disease risk, adjusting for sex and age. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR) method.Results. When comparing PTB patients with LTBI subjects, significant associations with disease development were observed for SNPs ofIL6andTNFα. When comparing LTBI subjects with HCS,IL1Bpolymorphisms were significantly associated with LIBI. Haplotype analyses suggested that the CGG haplotype ofIL1Bwas associated with an increased risk of PTB (P=0.039, OR = 1.34, 95% CI: 1.01–1.76), while the TTGCG haplotype ofTNFαwas a protective factor against PTB (P=0.039, OR = 0.66, 95% CI: 0.44–0.98).Conclusion. Our study demonstrated thatIL1Bvariants were related to LTBI andIL6andTNFαvariants were associated with PTB.

Toll-like receptor (TLR) single nucleotide polymorphisms (SNPs) have been associated with regulation of TLR expression and development of active tuberculosis (TB). The objectives of this study were to determine whether TLR8 and TLR9 SNPs were associated with the development of latent TB infection (LTBI) and the subsequent pulmonary TB (PTB) in a Chinese Han population. Two independent samples were enrolled. The first sample contained 584 TB cases and 608 controls; the second sample included 204 healthy controls, 201 LTBI subjects and 209 bacteria-confirmed active PTB patients. Three SNPs (rs3764880, rs187084 and rs5743836) were genotyped. The associations between the SNPs and risk of LTBI or PTB were investigated using unconditional logistic regression analysis. The A-allele of TLR8 rs3764880 SNP was protective against the development of TB in males (A vs G, OR = 0.58, 95%CI = 0.37–0.91). The AA genotype of rs3764880 SNP was found to increase the risk of PTB among females with an OR of 4.81 (1.11–20.85). The G allele of TLR9 SNP rs187084 was found to increase the risk of PTB (G vs A, P = 0.01, OR = 1.48, 95% CI = 1.10–2.00), the significance was also observed under dominant genetic models. The GA-genotype of TLR9 rs187084 SNP was found to increase the risk of PTB with an OR of 1.68 (1.07–2.65), but was found to decrease the risk of MTB infection with an OR = 0.64 (0.41–0.98). TLR9_rs5743836 SNP was excluded from the data analyses, because the minimum allele frequency was< 1%. Our findings in two independent samples indicated that SNPs in TLR8 and TLR9 were associated with the development of TB, and highlight that SNPs may have different effects on disease pathogenesis and progression.

2′-5′-Oligoadenylate synthetase 1 (OAS1) plays an important role in inflammatory immune reactions. OAS1 polymorphisms have been associated with increased susceptibility to various diseases. We investigated the association of polymorphisms in OAS1 with tuberculosis (TB). A total of 1215 TB cases and 1114 healthy controls were enrolled from two independent studies. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR) method. Associations between OAS1 polymorphisms (rs2240190, rs1131454, 10,774,671 and 11,066,453) and TB risk were established based on distributions of allelic frequencies using different genetic models. Significant association was observed between rs10774671, rs1131454 and TB. In the initial study, the G allele of rs10774671 was a significantly protective factor against TB (P = 0.006) and the genotype of GG differed significantly between TB patients and controls under the codominant model (P = 0.008) after Bonferroni correction. In the validation study, we also observed that the rs10774671 G allele (P = 0.001) and GG genotype (P = 0.001) were associated with TB. In addition, we found that the rs1131454 G allele (P = 0.004) and GG genotype (P = 0.001) were protective against TB in the Chinese Han population. We report novel associations of polymorphisms in OAS1 with TB in the Chinese Tibetan and Han populations. Similar studies in different populations and functional studies are warranted to confirm our results.

Previous studies indicated that single-nucleotide polymorphisms (SNPs) of interferon gamma (IFNG) and IFNG receptor 1 (IFNGR1) may be involved in the pathogenesis of pulmonary tuberculosis (PTB) in different populations. In order to further explore the results in a Chinese Han population, this study was designed to investigate potential associations between the polymorphisms inIFNGandIFNGR1and susceptibility to latent tuberculosis infection (LTBI) and/or PTB in a Chinese Han population. A total of 209 PTB, 173 LTBI, and 183 healthy control subjects (HCS) were enrolled in our study. Genotyping was conducted using an improved multiplex ligase detection reaction (iMLDR). We performed a logistic regression including sex and age as covariates to test the effect of alleles/genotypes on LTBI and/or TB. All six markers studied inIFNGandIFNGR1conformed to the Hardy–Weinberg equilibrium (HWE). TheIFNGrs1861494 was significantly associated with LTBI in recessive model, and the CC+CT genotype decreased risk of LTBI by 50% (P=0.046,OR=0.50, 95%CI: 0.25-0.99). TheIFNGR1rs2234711 was significantly associated with LTBI, and allele A increased the risk of LTBI by 55% (P=0.047,OR=1.55, 95%CI: 1.00-2.40). In the present study, we found thatIFNGandIFNGR1polymorphisms were associated with LTBI.