Background: Cytokines play a major role in defense against Mycobacterium tuberculosis infection. Polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. Polymorphisms of the regulatory
cytokine gene, the interleukin (IL)-10 is associated with the risk of tuberculosis (TB) in different populations. However, IL-10 gene polymorphism and susceptibility to TB in Thai is still unknown.
Objective: The purpose of this study was to evaluate whether the common IL-10 promoter gene polymorphisms are associated with TB in Thai population.
Material and Method: Forty-eight patients with newly diagnosed pulmonary tuberculosis were studied. DNA samples were extracted from leukocytes and used to investigate -1087A/G, -819C/T, -252C/A (rs1800896, rs1800871, rs1800872) in IL-10 gene using restriction fragment length polymorphism (PCR-RFLP) methods.
Results: In this study, the genotype and allele frequencies of IL-10-1087A/G, -819C/T, -252C/A polymorphism did not
significantly different between TB patients and healthy controls ((genotype: p = 0.38, p = 0.92, p = 1; allele: p = 0.57, p = 0.77, p = 0.89, respectively).
Conclusion: The lack of association between common IL-10 promoter polymorphisms and TB susceptibility in this study may
provide clue for better understanding of IL-10-1087A/G, -819C/T, -252C/A polymorphism and TB susceptibility in Thai
population, which might facilitate the rationale design of vaccines. However, further studies in large scales population are
required for confirmation.

Keywords: IL-10, Cytokines, Single nucleotide polymorphism (SNP), Tuberculosis