title: Impaired antibody memory to varicella zoster virus in HIV-infected children: low antibody levels and avidity*.
abstract: OBJECTIVE
  HIV-infected children have impaired antibody responses after exposure to certain antigens. Our aim was to determine whether HIV-infected children had lower varicella zoster virus (VZV) antibody levels compared with HIV-infected adults or healthy children and, if so, whether this was attributable to an impaired primary response, accelerated antibody loss, or failure to reactivate the memory VZV response.
  
  
  METHODS
  In a prospective, cross-sectional and retrospective longitudinal study, we compared antibody responses, measured by enzyme-linked immunosorbent assay (ELISA), elicited by VZV infection in 97 HIV-infected children and 78 HIV-infected adults treated with antiretroviral therapy, followed over 10 years, and 97 age-matched healthy children. We also tested antibody avidity in HIV-infected and healthy children.
  
  
  RESULTS
  Median anti-VZV immunoglobulin G (IgG) levels were lower in HIV-infected children than in adults (264 vs. 1535 IU/L; P<0.001) and levels became more frequently unprotective over time in the children [odds ratio (OR) 17.74; 95% confidence interval (CI) 4.36-72.25; P<0.001]. High HIV viral load was predictive of VZV antibody waning in HIV-infected children. Anti-VZV antibodies did not decline more rapidly in HIV-infected children than in adults. Antibody levels increased with age in healthy (P=0.004) but not in HIV-infected children. Thus, antibody levels were lower in HIV-infected than in healthy children (median 1151 IU/L; P<0.001). Antibody avidity was lower in HIV-infected than healthy children (P<0.001). A direct correlation between anti-VZV IgG level and avidity was present in HIV-infected children (P=0.001), but not in healthy children.
  
  
  CONCLUSIONS
  Failure to maintain anti-VZV IgG levels in HIV-infected children results from failure to reactivate memory responses. Further studies are required to investigate long-term protection and the potential benefits of immunization.
authors: Department of Pediatrics, Geneva Medical Faculty and University Hospitals of Geneva, Geneva, Switzerland.
authors: A G
authors: AG
authors: L'Huillier
authors: T
authors: T
authors: Ferry
authors: D S
authors: DS
authors: Courvoisier
authors: C
authors: C
authors: Aebi
authors: J-J
authors: JJ
authors: Cheseaux
authors: C
authors: C
authors: Kind
authors: C
authors: C
authors: Rudin
authors: D
authors: D
authors: Nadal
authors: B
authors: B
authors: Hirschel
authors: C
authors: C
authors: Sottas
authors: C-A
authors: CA
authors: Siegrist
authors: K M
authors: KM
authors: Posfay-Barbe
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D000915:Antibody Affinity / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D004812:Epidemiologic Methods; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology*; D008297:Male; D013557:Switzerland
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G