Gene expression signature of tolerance and lymphocyte subsets in stable renal transplants: results of a cross-sectional study

Transpl Immunol. 2014 Jun;31(1):11-6. doi: 10.1016/j.trim.2014.04.008. Epub 2014 May 5.


Background: In kidney transplants operational tolerance has been associated with up-regulation of B cell differentiation genes and an increased number of total, naive and transitional peripheral B cells. The aim is to evaluate tolerance biomarkers in different cohorts of stable renal transplants under immunosuppression.

Methods: This is a cross-sectional study conducted in renal transplants. We evaluate genetic tolerance signature and lymphocyte subsets in stable transplants treated with calcineurin inhibitors (CNI) at 1 (n=15), 5 (n=14) and 10 (n=16) years, and azathioprine-treated transplants followed 30 years (n=8). Healthy volunteers (n=10) and patients with chronic rejection (n=15) served as controls.

Results: We confirm that peripheral expression of IGKV1D-13 and IGKV4-1 genes by RT-PCR distinguish tolerant (n=10) from stable transplants (n=10) provided by the International Tolerance Network. Tolerance signature was defined as the lowest expression for both genes in tolerant patients. In CNI-treated patients, genetic signature of tolerance and B cells showed a time-dependent increase not observed in azathioprine-treated patients (p<0.01). Genetic tolerance signature was observed in 0% at 1, 7% at 5 and 25% at 10-years while it was not observed in azathioprine-treated and chronic rejection patients. Fifteen out of 16 CNI-treated transplants at 10 years were revaluated 3 months apart. Nine did not show the tolerance signature in any determination, 4 in one and 2 in both determinations. Genetic signature of tolerance was associated with an increase of total, naive and transitional B cells (p<0.05).

Conclusions: IGKV1D-13 and IGKV4-1 gene expression and its linked B cell populations increase during follow up in CNI-treated patients. At 10 years, 2 out of 15 CNI treated patients consistently express biomarkers associated with true tolerance. In azathioprine-treated patients these biomarkers were down-regulated.

Keywords: B cells; Chronic rejection; Immunosuppression; Lymphocyte subpopulations; Operational tolerance; Renal transplantation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azathioprine / therapeutic use
  • B-Lymphocyte Subsets / immunology
  • B-Lymphocytes / immunology*
  • Calcineurin Inhibitors / therapeutic use
  • Cross-Sectional Studies
  • Female
  • Humans
  • Immune Tolerance / drug effects
  • Immune Tolerance / genetics*
  • Immune Tolerance / immunology*
  • Immunocompromised Host / genetics*
  • Immunocompromised Host / immunology
  • Immunoglobulin kappa-Chains / genetics
  • Immunophenotyping
  • Immunosuppressive Agents / therapeutic use
  • Kidney Transplantation*
  • Male
  • Middle Aged
  • Oligonucleotide Array Sequence Analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcriptome


  • Calcineurin Inhibitors
  • Immunoglobulin kappa-Chains
  • Immunosuppressive Agents
  • Azathioprine