title: Chronic Hepatitis C Virus Infection and the Proinflammatory Effects of Injection Drug Use.
abstract: BACKGROUND
  Chronic inflammation, as defined by persistent immune activation, is associated with adverse clinical outcomes. People who inject drugs (PWID) have evidence of persistent immune activation. Here, in a cohort of PWID with or without hepatitis C virus (HCV) infection, we sought to dissect out the contribution of chronic HCV infection (common in PWID) from the effects of injection drug use itself.
  
  
  METHODS
  Four groups of study volunteers were recruited: group 1 comprised active PWID; group 2, individuals who ceased injecting drugs 1-2 months before recruitment; group 3, individuals who ceased injecting drugs 3-4 months before recruitment; and group 4, healthy volunteers. Soluble and cell-associated markers of immune activation were quantified.
  
  
  RESULTS
  HCV-viremic PWID have elevated levels of immune activation when compared to healthy volunteers. Cessation of injection drug use results in a decline in immune activation in the absence of HCV viremia, while HCV-viremic individuals who previously were PWID continue to harbor elevated levels of immune activation, as defined by increased levels of soluble CD14 and tumor necrosis factor α and by the presence of CD38+HLA-DR+CD4+and CD8+T cells.
  
  
  CONCLUSIONS
  Immune activation, a well-defined surrogate of poor clinical outcome that is elevated in PWID, can regress to normal levels in former injection drug users who are HCV aviremic. Therefore, enhanced harm-reduction efforts should incorporate aggressive treatment of HCV infection.
  
  
  BACKGROUND
  NCT01831284.
authors: Aaron Diamond AIDS Research Center.
authors: Martin
authors: M
authors: Markowitz
authors: Center for Drug Use and HIV Research, New York University Rory Meyers College of Nursing.
authors: Sherry
authors: S
authors: Deren
authors: Center for Drug Use and HIV Research, New York University Rory Meyers College of Nursing.
authors: Charles
authors: C
authors: Cleland
authors: Aaron Diamond AIDS Research Center.
authors: Melissa
authors: M
authors: La Mar
authors: Center for Drug Use and HIV Research, New York University Rory Meyers College of Nursing.
authors: Evelyn
authors: E
authors: Silva
authors: Center for Drug Use and HIV Research, New York University Rory Meyers College of Nursing.
authors: Pedro
authors: P
authors: Batista
authors: Aaron Diamond AIDS Research Center.
authors: Leslie
authors: L
authors: St Bernard
authors: Aaron Diamond AIDS Research Center.
authors: Natanya
authors: N
authors: Gettie
authors: Aaron Diamond AIDS Research Center.
authors: Kristina
authors: K
authors: Rodriguez
authors: Aaron Diamond AIDS Research Center.
authors: Teresa H
authors: TH
authors: Evering
authors: Immunology Institute.|Department of Gastroenterology, Icahn School of Medicine at Mt. Sinai, New York.
authors: Haekyung
authors: H
authors: Lee
authors: Immunology Institute.|Department of Gastroenterology, Icahn School of Medicine at Mt. Sinai, New York.
authors: Saurabh
authors: S
authors: Mehandru
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D055030:Drug Users; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000209:etiology* / Q000276:immunology; D008297:Male; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: HCV infection; immune activation; injection drug use