title: CD4+ T cell-dependent reduction in hepatitis C virus-specific humoral immune responses after HIV infection.
abstract: BACKGROUND
  Human immunodeficiency virus (HIV) infection adversely affects all stages of hepatitis C virus (HCV) infection, leading to increased rates of viral persistence, higher levels of HCV viremia, and accelerated progression of HCV-related liver disease. These disease interactions may result in part from impairment of B cell function, which is CD4(+) T cell dependent.
  
  
  METHODS
  To determine the effect of HIV infection on B cell function, we compared HCV antibody levels and specificities in 29 HCV-infected persons before and after they acquired HIV and assessed the temporal correlation of these changes with overall CD4(+) T lymphocyte counts.
  
  
  RESULTS
  The pre-HIV infection HCV antibody titer was a predictor of the subsequent titer for all antigens, and decreasing CD4(+) T cell numbers was strongly associated with a decrease in anti-HCV titers for several antigens. CD4(+) T cells counts of <500 cells/mm(3) were significantly associated with lower HCV antibody end-point titers. Higher HCV end-point titers were associated with fewer years from HIV infection and, for Core antigen, current drug use.
  
  
  CONCLUSIONS
  HCV-specific antibody production is impaired by HIV infection, and loss of antibody production depends on CD4(+) T cell depletion. However, the decrease in titers is less significant in those who continue to actively inject drugs.
authors.affiliation: Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, 21231, USA. dnetski1@jhmi.edu
authors.forename: Dale M
authors.initials: DM
authors.lastname: Netski
authors.forename: Tim
authors.initials: T
authors.lastname: Mosbruger
authors.forename: Jacquie
authors.initials: J
authors.lastname: Astemborski
authors.forename: Shruti H
authors.initials: SH
authors.lastname: Mehta
authors.forename: David L
authors.initials: DL
authors.lastname: Thomas
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Cox
mesh_terms: D000328:Adult; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D018791:CD4 Lymphocyte Count; D005260:Female; D015483:HIV Antibodies / Q000097:blood; D015658:HIV Infections / Q000276:immunology*; D016174:Hepacivirus / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008137:Longitudinal Studies; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D015819:Substance Abuse, Intravenous / Q000276:immunology*; D019562:Viral Load
chemical_list: D015483:HIV Antibodies; D007074:Immunoglobulin G