Variations in inflammatory genes as molecular markers for prediction of inflammatory bowel disease occurrence

J Dig Dis. 2015 Dec;16(12):723-33. doi: 10.1111/1751-2980.12281.

Abstract

Objective: Research on inflammatory bowel disease (IBD) has highlighted genes involved in the regulation of inflammatory responses as contributors to disease pathogenesis. This study aimed to evaluate the associations between IBD and variations in NOD2, TLR4, TNF-α, IL-6, IL-1β and IL-1RN genes, and to use the genetic data obtained in predictive modeling.

Methods: A total of 167 IBD patients and 101 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Using the genotype data attained as the input to various classification algorithms, IBD prediction models were designed. The area under the receiver operating characteristic curve (AUROC) was used to measure their performance.

Results: Significant associations were found between Crohn's disease (CD) and minor NOD2 variants, as well as TLR4 299Gly, TNF-α G-308A, IL-6 G-174C and IL-1RN VNTR A2 variants, while ulcerative colitis (UC) was associated only with IL-1RN VNTR A2 variants. CD and UC showed highly significant difference in the allelic distribution of TNF-α G-308A, where the A allele was found to be related to CD, and the G allele to UC. A combined effect of patients' gender and TLR4 variants was observed among CD patients. When all analyzed genotype and gender data were used, prediction performance achieved a maximum AUROC of 0.690 for CD and 0.601 for UC dataset.

Conclusion: Variations in the genes involved in immune regulation are genetic factors of importance in IBD susceptibility that could potentially be used as predictors of disease development.

Keywords: Serbian cohort; genetic variant; inflammatory bowel disease; inflammatory gene; predictive modeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alleles
  • Biomarkers / blood
  • Case-Control Studies
  • Colitis, Ulcerative / blood
  • Colitis, Ulcerative / genetics*
  • Crohn Disease / blood
  • Crohn Disease / genetics*
  • Female
  • Genetic Markers
  • Genetic Predisposition to Disease / genetics*
  • Genetic Testing
  • Genotype
  • Humans
  • Interleukin 1 Receptor Antagonist Protein / blood
  • Interleukin 1 Receptor Antagonist Protein / genetics
  • Interleukin-1beta / blood
  • Interleukin-1beta / genetics
  • Interleukin-6 / blood
  • Interleukin-6 / genetics
  • Intracellular Signaling Peptides and Proteins / blood
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Male
  • Middle Aged
  • Minisatellite Repeats
  • Nod2 Signaling Adaptor Protein / blood
  • Nod2 Signaling Adaptor Protein / genetics
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Predictive Value of Tests
  • Serbia
  • Sex Factors
  • Toll-Like Receptor 4 / blood
  • Toll-Like Receptor 4 / genetics
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / genetics
  • White People / genetics
  • Young Adult

Substances

  • Biomarkers
  • Genetic Markers
  • IL1RN protein, human
  • IL6 protein, human
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1beta
  • Interleukin-6
  • Intracellular Signaling Peptides and Proteins
  • NOD2 protein, human
  • Nod2 Signaling Adaptor Protein
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha