The IL-17F sequence variant is associated with susceptibility to tuberculosis.

The interleukin (IL)-17 gene plays a key role in host defence against infections from microbes, including Mycobacterium tuberculosis. Genetic factors contribute to host defence. However, whether genetic variation in IL-17 is associated with altered susceptibility to tuberculosis is unknown. A total of 596 pulmonary tuberculosis (PTB) patients, 176 extra-pulmonary tuberculosis (EPTB) patients, and 622 control patients from a Chinese Han population were recruited. Two single-nucleotide polymorphisms (SNPs) in IL-17F (rs1889570 and rs763780) and one SNP in IL-17A (rs2275913) were genotyped using the SNaPshot technique. Of the three SNPs in the IL-17 gene tested, there was an increased frequency of the rs1889570 G allele and the rs763780 C allele in the PTB patients and an increased frequency of the rs763780 C allele in the EPTB patients compared with the control patients. There were also significant differences in the distribution of the rs763780 genotype between the PTB and EPTB patients and the controls. The patients who had the CT/TT genotype of the rs763780 SNP were more susceptible to tuberculosis, compared to the CC genotype. There was no significant difference observed between the IL-17 SNPs when the PTB and EPTB patients were compared. Genetic variation in IL-17F is associated with altered susceptibility to tuberculosis and may provide valuable information in the development of tuberculosis.