title: Effect of exposure to injection drugs or alcohol on antigen-specific immune responses in HIV and hepatitis C virus coinfection.
abstract: BACKGROUND
  Ongoing substance use is a potential confounder for immunological studies on hepatitis C virus (HCV), but there is little in the literature regarding the effects of injection drug use (IDU) or alcohol on HCV-specific immune responses. We wanted to determine whether IDU or alcohol affected immune responses in HCV-infected and human immunodeficiency virus (HIV)/HCV coinfected subjects.
  
  
  METHODS
  Eight-four subjects with HIV/HCV and 57 with HCV were classified as either injection drug users, drinkers, or nonusers based on questionnaire results. Immune responses were studied with enzyme-linked immunosorbent spot assay for interferon (IFN)- gamma , interleukin (IL)-10, and tumor necrosis factor (TNF)- alpha against HCV proteins Core, NS3, and NS5 and recall antigens.
  
  
  RESULTS
  Subjects with HIV/HCV, in aggregate, had significantly lower HCV-specific IFN- gamma and TNF- alpha responses than subjects with HCV. However, HIV/HCV injection drug users had HCV-specific IFN- gamma and IL-10 responses that were similar to those of HCV injection drug users and were significantly higher than in nonusers with HIV/HCV. Conversely, subjects who drank alcohol had similar immune responses to those who were abstinent, among both subjects with HIV/HCV and subjects with HCV.
  
  
  CONCLUSIONS
  Studies that examine IFN- gamma or IL-10 immune responses in HIV/HCV-coinfected or HCV-infected persons need to consider current IDU. Alcohol, at levels consumed in this cohort, does not appear to have as much of an effect on antigen-specific immune responses.
authors.affiliation: Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA. cgraham@bidmc.harvard.edu
authors.forename: Camilla S
authors.initials: CS
authors.lastname: Graham
authors.forename: Annalee
authors.initials: A
authors.lastname: Wells
authors.forename: Erika M
authors.initials: EM
authors.lastname: Edwards
authors.forename: Timothy
authors.initials: T
authors.lastname: Herren
authors.forename: Sheila
authors.initials: S
authors.lastname: Tumilty
authors.forename: Sherri O
authors.initials: SO
authors.lastname: Stuver
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Samet
authors.forename: David
authors.initials: D
authors.lastname: Nunes
authors.forename: C Robert
authors.initials: CR
authors.lastname: Horsburgh
authors.forename: Margaret James
authors.initials: MJ
authors.lastname: Koziel
mesh_terms: D000328:Adult; D000428:Alcohol Drinking; D000437:Alcoholism; D015986:Confounding Factors, Epidemiologic; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D006556:Heroin Dependence; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D015819:Substance Abuse, Intravenous
chemical_list: D016753:Interleukin-10; D007371:Interferon-gamma