title: [Dynamic changes in programmed death-1 expression on the surface of T cells in chronic hepatitis C patients undergoing interferon therapy].
abstract: OBJECTIVE
  To investigate the dynamic changes that occur in T cell subsets, particularly involving the surface expression of programmed death 1 (PD-1), in response to pegylated (Peg)-interferon (IFN) a-2a therapy in patients with chronic hepatitis C virus (HCV) infection.
  
  
  METHODS
  Twenty-five patients with HCV genotype 1b chronic infection and 10 healthy controls were enrolled in the study. All the HCV patients received combination antiviral therapy of Peg-IFNa-2a (180 mug/week) plus ribavirin. At treatment weeks 0 (baseline), 4, 12, 24 and 48, the level of PD-1 protein expression on the surface of total peripheral CD8+ and CD4+ T cells was determined by flow cytometry and the level of PD-1 mRNA expression in peripheral blood mononuclear cells (PBMCs) was determined by reverse transcription-polymerase chain reaction. Independent student's t-test were used to compare mean values between the two groups, repeat measure variance analysis was used to compare mean values among multiple groups, and Pearson's correlation coefficient was used to assess correlation significance.
  
  
  RESULTS
  Over the course of antiviral therapy, the proportions of CD4+ T cells and CD8+ T cells, as well as the CD4+/CD8+ ratio, increased (F = 81.23, 39.28, and 7.01 respectively; all P less than 0.01). In contrast, the PD-1 protein expression frequency on CD4+ T cells and CD8+ T cells significantly declined (F = 100.11 and 158.40 respectively; all P less than 0.01). The PD-1-mRNA expression level in PBMCs was: 1.40+/-0.26 at baseline, 1.30+/-0.27 at week-4, 1.14+/-0.18 at week-12, 1.06+/-0.26 at week-24, and 0.83+/-0.25 at week-48 (F = 20.09; P less than 0.01). A positive correlation existed between the PD-1 protein expression frequencies on CD4+ T cells and CD8+ T cells and the HCV RNA load detected at baseline (r = 0.82 and 0.75 respectively; all P less than 0.01).
  
  
  CONCLUSIONS
  The ability of Peg-IFN-a-2a-based antiviral therapy to suppress HCV replication may involve reduction of PD-1 protein expression on the surface of CD8+ T cells and CD4+ T cells.
authors.affiliation: Department of Infectious Diseases, the Third Hospital of Hebei Medical University, Shijiazhuang 050051, China.
authors.forename: Rong-qiao
authors.initials: RQ
authors.lastname: Dong
authors.forename: Dong-fang
authors.initials: DF
authors.lastname: Zhou
authors.forename: Ran
authors.initials: R
authors.lastname: Han
authors.forename: Jun-ying
authors.initials: JY
authors.lastname: Zhou
authors.forename: Cai-yan
authors.initials: CY
authors.lastname: Zhao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhen
mesh_terms: D000293:Adolescent; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D061026:Programmed Cell Death 1 Receptor / Q000378:metabolism*; D011994:Recombinant Proteins / Q000627:therapeutic use; D012254:Ribavirin / Q000627:therapeutic use; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C100416:peginterferon alfa-2a