title: CD4/CD8 Ratio Predicts Yellow Fever Vaccine-Induced Antibody Titers in Virologically Suppressed HIV-Infected Patients.
abstract: BACKGROUND
  Yellow fever vaccine (YFV) induces weaker immune responses in HIV-infected individuals. However, little is known about YFV responses among antiretroviral-treated patients and potential immunological predictors of YFV response in this population.
  
  
  METHODS
  We enrolled 34 antiretroviral therapy (ART)-treated HIV-infected and 58 HIV-uninfected adults who received a single YFV dose to evaluate antibody levels and predictors of immunity, focusing on CD4(+) T-cell count, CD4(+)/CD8(+) ratio, and Human Pegivirus (GBV-C) viremia. Participants with other immunosuppressive conditions were excluded.
  
  
  RESULTS
  Median time since YFV was nonsignificantly shorter in HIV-infected participants than in HIV-uninfected participants (42 and 69 months, respectively, P = 0.16). Mean neutralizing antibody (NAb) titers was lower in HIV-infected participants than HIV-uninfected participants (3.3 vs. 3.6 log10mIU/mL, P = 0.044), a difference that remained significant after adjustment for age, sex, and time since vaccination (P = 0.024). In HIV-infected participants, lower NAb titers were associated with longer time since YFV (rho: -0.38, P = 0.027) and lower CD4(+)/CD8(+) ratio (rho: 0.42, P = 0.014), but not CD4(+) T-cell count (P = 0.52). None of these factors were associated with NAb titers in HIV-uninfected participant. GBV-C viremia was not associated with difference in NAb titers overall or among HIV-infected participants.
  
  
  CONCLUSIONS
  ART-treated HIV-infected individuals seem to have impaired and/or less durable responses to YFV than HIV-uninfected individuals, which were associated with lower CD4(+)/CD8(+) ratio, but not with CD4(+) T-cell count. These results supports the notion that low CD4(+)/CD8(+) ratio, a marker linked to persistent immune activation, is a better indicator of functional immune disturbance than CD4(+) T-cell count in patients with successful ART.
authors.affiliation: *Department of Infectious and Parasitic Diseases, University of Sao Paulo Medical School, Sao Paulo, Brazil; †Division of Clinic Immunology and Allergy, University of Sao Paulo Medical School, Sao Paulo, Brazil; ‡Fundação Oswaldo Cruz Bio-Manguinhos, Rio de Janeiro, Brazil; §Adolfo Lutz Institute, Sao Paulo, Brazil; and ‖Laboratories of Medical Investigation LIM-3, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Vivian Iida
authors.initials: VI
authors.lastname: Avelino-Silva
authors.forename: Karina Takesaki
authors.initials: KT
authors.lastname: Miyaji
authors.forename: Augusto
authors.initials: A
authors.lastname: Mathias
authors.forename: Dayane Alves
authors.initials: DA
authors.lastname: Costa
authors.forename: Juliana Zanatta
authors.initials: JZ
authors.lastname: de Carvalho Dias
authors.forename: Sheila Barbosa
authors.initials: SB
authors.lastname: Lima
authors.forename: Marisol
authors.initials: M
authors.lastname: Simoes
authors.forename: Marcos S
authors.initials: MS
authors.lastname: Freire
authors.forename: Helio H
authors.initials: HH
authors.lastname: Caiaffa-Filho
authors.forename: Marisa A
authors.initials: MA
authors.lastname: Hong
authors.forename: Marta H
authors.initials: MH
authors.lastname: Lopes
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sartori
authors.forename: Esper G
authors.initials: EG
authors.lastname: Kallas
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D019562:Viral Load; D022341:Yellow Fever Vaccine / Q000276:immunology*
chemical_list: D019380:Anti-HIV Agents; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D022341:Yellow Fever Vaccine