Common variants of T-cells contribute differently to phenotypic variation in sarcoidosis

Sci Rep. 2017 Jul 17;7(1):5623. doi: 10.1038/s41598-017-05754-7.

Abstract

The involvement of the immune system, particularly the role of T-cells, in sarcoidosis is unclear. The existence of higher CD4+ T-cells and increased CD4/CD8 ratio may indicate a pathogenic role of T-cells in the disease. In this study, we quantified the contribution of T-cells associated variants and of CD4/CD8 ratio in sarcoidosis phenotypes, Löfgren's syndrome (LS) and non- Löfgren's syndrome (non-LS). We employed a polygenic-based approach using genome-wide association studies results on relative levels of T-cells in healthy individuals to measure the genetic contribution of T-cells in sarcoidosis entities. Results revealed that the genetic architecture of LS is highly influenced by genetic variants associated with CD8+ T-cells and CD4/CD8 ratio, explaining up to 7.94% and 6.49% of LS variation, respectively; whereas, the genetic architecture of non-LS is minimally influenced by T-cells, explaining a phenotypic variation of <1%. Moreover, pleiotropy assessment between T-cells and LS/non-LS associated-variants led to the discovery of highly scored pathway maps that shared common factors related to antigen presentation and T-cell regulatory mechanisms. Differences in significant polygenic scores, presence of pleiotropy, and distinct genetic factors provide further insights on how genetic variants and genes associated with relative levels of T-cell subtypes contribute differently to sarcoidosis phenotypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Female
  • Genetic Pleiotropy
  • Genetic Predisposition to Disease
  • Genome-Wide Association Study
  • HLA-DRB1 Chains / genetics*
  • Humans
  • Male
  • Middle Aged
  • Phenotype
  • Polymorphism, Single Nucleotide*
  • Sarcoidosis / genetics*
  • T-Lymphocytes / immunology*
  • Young Adult

Substances

  • HLA-DRB1 Chains