IL-6 and IL-18 cytokine gene variants of pulmonary tuberculosis patients with co-morbid diabetes mellitus and their household contacts in Hyderabad

Gene. 2017 Sep 5:627:298-306. doi: 10.1016/j.gene.2017.06.046. Epub 2017 Jun 23.

Abstract

Purpose: Association of cytokine genes reflects their susceptibility towards infection and disease in household contacts (HHC) of pulmonary tuberculosis (PTB) patients. Hyperglycemia, a common factor in diabetics might influence their risk towards mycobacterium tuberculosis infection and disease development. This study determines the association of IL-6 and IL-18 cytokine gene variants of TB patients with diabetes mellitus (TBDM) and their HHC in Hyderabad.

Methods: Single nucleotide polymorphisms of IL-6 (-174 G>C and -572 G>C) and IL-18 (-137 G>C and -607 C>A) cytokine genes were genotyped by Amplification Refractory Mutation System and Restriction Fragment Length polymerase chain reaction in total of 705 subjects comprising of TBDM, their HHC, PTB, DM and Healthy controls (HC).

Results: At IL-6 -174G>C variant, GG genotype, G allele in TBDM and TBDM HHC, at -572G>C variant, C allele in TBDM and GG haplotype in TBDM HHC were showing positive association, however DM have not shown any association at IL-6 polymorphic sites. With respect to the IL-18 gene polymorphisms, at -137 G>C variant, GG genotype was positively associated in PTB while at -607 C>A variant positive association was shown with AC genotype in TBDM, their HHC and DM; GACC diplotype in TBDM and GCGC in PTB.

Conclusion: Our findings suggest that susceptible combination of IL-6 and IL-18 cytokine genes associated with disease in the HHCs highlight their risk of inclination towards the disease.

Keywords: Household contacts; Multidimensionality reduction; Single nucleotide polymorphisms; Tuberculosis with diabetes mellitus.

MeSH terms

  • Adult
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / genetics*
  • Family Characteristics
  • Female
  • Genotype
  • Humans
  • India
  • Interleukin-18 / genetics*
  • Interleukin-6 / genetics*
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide*
  • Tuberculosis, Pulmonary / complications
  • Tuberculosis, Pulmonary / epidemiology
  • Tuberculosis, Pulmonary / genetics*

Substances

  • IL6 protein, human
  • Interleukin-18
  • Interleukin-6