Cytokine gene polymorphisms are associated with susceptibility to tuberculosis in an Amerindian population.

SETTING

Cytokines play an important role in anti-tuberculosis immune response, combined with antigen-presenting cells and lymphocytes. Immune response gene polymorphisms have been reported to be associated with tuberculosis (TB) susceptibility in some but not all studies.

OBJECTIVE

To evaluate the association of immune response genes with susceptibility to tuberculin skin test (TST) reactivity and/or TB.

DESIGN

Fourteen single nucleotide polymorphisms were genotyped in 96 individuals of the Aché, a native Paraguayan population, by allelic discrimination using real-time polymerase chain reaction. Univariate and multivariate Poisson regression were employed to assess risk genotypes.

RESULTS

A higher prevalence of purified protein derivative reactivity was associated with the TNF-α CCA/TCG haplotype (PR 1.298, 95%CI 1.059-1.589) and with the IL-10 AT/CC diplotype (PR 1.181, 95% CI 1.024-1.362), and the presence of the IL-8 rs4073 T allele was associated with protection against TB (PR 0.482, 95%CI 0.273-0.851).

CONCLUSIONS

These results suggest that polymorphisms in genes associated with immune response are involved in TST reactivity and susceptibility to TB in the Aché population.