PD-1 expression on peripheral CD8+ TEM/TEMRA subsets closely correlated with HCV viral load in chronic hepatitis C patients

Virol J. 2010 Nov 12;7:310. doi: 10.1186/1743-422X-7-310.


Background: Tight correlation between host circulating CD8+ T cell-mediated immune response and control of viral replication is classical characteristic of long-term HCV infection. CD8+ T cell maturation/activation markers are expected to be associated with viral replication and disease progression in chronic HCV infection. The aim of the present study was to explore novel markers on CD8+ T cells with ability to evaluate HCV viral replication and disease progression.

Methods: PBMCs were isolated from 37 chronic HCV-infected patients and 17 healthy controls. Distributed pattern of CD8+ T cells subsets and expression of PD-1, CD38, HLA-DR and CD127 were analyzed by flow cytometry. The correlation between expression of surface markers and HCV viral load or ALT was studied.

Results: Declined naïve and increased TEMRA CD8+ T subsets were found in HCV-infected individuals compared with healthy controls. Percentage and MFI of PD-1, CD38 and HLA-DR on all CD8+ T cell subsets were higher in HCV-infected patients than healthy controls. In contrast, CD127 expression on CD8+ TCM showed an opposite trend as PD-1, CD38 and HLA-DR did. In chronic HCV infection, MFI of PD-1 on CD8+ TEM (p < 0.0001) and TEMRA (p = 0.0015) was positively correlated with HCV viral load while HLA-DR expression on non-naive CD8+ T cell subsets (p < 0.05) was negatively correlated with HCV viral load.

Conclusion: PD-1 level on peripheral CD8+ TEM/TEMRA was highly correlated with HCV viral load in chronic HCV-infected patients, which made PD-1 a novel indicator to evaluate HCV replication and disease progression in chronic hepatitis C patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alanine Transaminase / blood
  • Antigens, CD / biosynthesis*
  • Apoptosis Regulatory Proteins / biosynthesis*
  • Biomarkers
  • CD8-Positive T-Lymphocytes / chemistry*
  • CD8-Positive T-Lymphocytes / immunology
  • Cells, Cultured
  • Flow Cytometry
  • Gene Expression*
  • Hepacivirus / isolation & purification*
  • Hepatitis C, Chronic / immunology*
  • Humans
  • Middle Aged
  • Programmed Cell Death 1 Receptor
  • T-Lymphocyte Subsets / chemistry*
  • T-Lymphocyte Subsets / immunology
  • Viral Load*


  • Antigens, CD
  • Apoptosis Regulatory Proteins
  • Biomarkers
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor
  • Alanine Transaminase