PLoS ONE (Jan 2021)

Interleukin-18 and interferon-γ single nucleotide polymorphisms in Egyptian patients with tuberculosis.

  • Noha A Hassuna,
  • Mohamed El Feky,
  • Aliae A R Mohamed Hussein,
  • Manal A Mahmoud,
  • Naglaa K Idriss,
  • Sayed F Abdelwahab,
  • Maggie A Ibrahim

DOI
https://doi.org/10.1371/journal.pone.0244949
Journal volume & issue
Vol. 16, no. 1
p. e0244949

Abstract

Read online

BackgroundInterleukin-18 (IL-18) and interferon-γ (IFN-γ) are cytokines of crucial role in inflammation and immune reactions. There is a growing evidence supporting important roles for IL-18 and IFN γ in tuberculosis (TB) infection and anti-tuberculosis immunity.ObjectiveTo evaluate the role of polymorphisms in IL-18-607 and -137 and INF-γ +874 in susceptibility to TB infection among Egyptian patients.MethodsA case control study was conducted to investigate the polymorphism at IL-18-607, -137 and INF-γ+874 by sequence specific primer-polymerase chain reaction (SSP- PCR) in 105 patients with pulmonary and extra pulmonary tuberculosis and 106 controls.ResultsA significant protective effect against TB was found in homozygous CC genotype at IL-18 -137G/C, in addition to a 7-fold risk with GG and GC genotypes in the recessive model. Apart from a decreased risk with the AC genotype, no association was detected between the susceptibility to TB and different genotypes or alleles at the IL-18 -607A/C site. The homozygous AA genotype in INF-γ+874 showed a significant higher risk to TB than the homozygous TT or heterozygous AT genotypes with nearly a 2-fold risk of TB infection with the A allele. Regarding haplotype association, the GC haplotype was strongly associated with TB infection compared to other haplotypes.ConclusionThese findings suggest; for the first time in Egypt; a significant risk to TB infection with SNP at the IL-18-137G/C with no LD with SNP at the IL-18-607 site. The homozygous AA genotype in INF-γ+874 showed a significant higher risk to TB than the homozygous TT or heterozygous AT genotypes.