title: Impact of maternal HIV-1 viremia on lymphocyte subsets among HIV-exposed uninfected infants: protective mechanism or immunodeficiency.
abstract: BACKGROUND
  Reports of increased morbidity and mortality from infectious diseases among HIV Exposed Uninfected (HEU) infants have raised concern about a possible underlying immunodeficiency among them. The objective of this study was to assess the immunological profile of HEU infants born to mothers exhibiting different levels of HIV-1 viremia at the time of delivery.
  
  
  METHODS
  Study subjects were enrolled in the Centre maternel et infantile sur le SIDA (CMIS) mother-child cohort between 1997 and 2010 (n =585). Infant CD4+ T cell, CD8+ T cell and CD19+ B cell counts were assessed at 2 and 6 months of age, and compared among HEU infants in groups defined by maternal viral load (VL) at the time of delivery (VL < 50 copies/ml, VL 50-1000 copies/ml, and VL > 1000 copies/ml) in a multivariable analysis.
  
  
  RESULTS
  At 2 months of age, infants born to mothers with VL > 1000 copies/ml had lower CD4+ T cell counts compared to those born to mothers with VL < 50 copies/ml at the time of delivery (44.3% versus 48.3%, p = 0.007, and 2884 vs. 2432 cells/mm3, p = 0.02). These differences remained significant after adjusting for maternal and infant antiretroviral drug use, gender, race and gestational age, and persisted at 6 months of age. There were no differences in CD8+ T cell count or absolute CD19+ B cell count between groups, though higher CD19+ B cell percentage was seen among infants born to mothers with VL > 1000 copies/ml.
  
  
  CONCLUSIONS
  These results suggest that exposure to high levels of HIV-1 viremia in utero, even in the absence of perinatal transmission, may affect the infant's developing immune system. While further work needs to be done to confirm these findings, they reinforce the need for optimal treatment of HIV infected pregnant women, and careful follow-up of HEU infants.
authors.affiliation: Division of Infectious Diseases, CHU Sainte-Justine, 3175 Côte Sainte-Catherine, Montreal, Quebec H3T 1C5, Canada. fatima.kakkar@umontreal.ca.
authors.forename: Fatima
authors.initials: F
authors.lastname: Kakkar
authors.forename: Valerie
authors.initials: V
authors.lastname: Lamarre
authors.forename: Thierry
authors.initials: T
authors.lastname: Ducruet
authors.forename: Marc
authors.initials: M
authors.lastname: Boucher
authors.forename: Silvie
authors.initials: S
authors.lastname: Valois
authors.forename: Hugo
authors.initials: H
authors.lastname: Soudeyns
authors.forename: Normand
authors.initials: N
authors.lastname: Lapointe
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D005260:Female; D015658:HIV Infections / Q000276:immunology / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000276:immunology*; D018445:Infectious Disease Transmission, Vertical; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male; D009035:Mothers; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000821:virology*; D019562:Viral Load; D014766:Viremia / Q000276:immunology / Q000821:virology*