Objective: To investigate the association of IL-10, IFN-γ gene polymorphisms at position -1082G/A and +874A/T and susceptibility to pulmonary tuberculosis (PTB) through a case-control study.
Methods: Polymerase chain reaction with sequence specific primer (PCR-SSP)/sequencing method, single nucleotide polymorphisms (SNP) of IL-10 and IFN-γ gene at position -1082 and +874 were used on pulmonary tuberculosis patients (group PTB) and normal healthy subjects (group NHS) in the Han population from Shenzhen city of China.
Results: The genotype frequencies of A/A homozygotes, A/G heterozygous and G/G homozygous at -1082 site of IL-10 gene in patients with pulmonary tuberculosis were 85.4%, 13.1%, 1.5% respectively and A, G allele frequencies were 91.9%, 8.1% respectively. In healthy subjects, the genotype frequencies of A/A homozygotes, A/G heterozygous and G/G homozygous were 77.5%, 22.0%, 0.5% respectively and A, G allele frequencies were 88.5%, 11.5% respectively. Genotype distribution between the two groups was significantly different (P < 0.05). The genotype frequencies of A/A of IL-10 in the patient group were higher than that of control group. In contrast, the genotype frequencies of G/A in the control group were higher than that in the patient group (P < 0.05). There was no statistical difference found between A and G allele (P > 0.05). For IFN-γ (+874) and no significant difference was found on the distribution of genotypes or alleles between the two groups.
Conclusion: The IL-10 (-1082) gene SNP might be associated with the susceptibility to tuberculosis. A/A genotype might be a risk factor for the susceptibility on tuberculosis while the SNP of cytokines (+874) might not be associated with the susceptibility to tuberculosis in Chinese Han populations.