title: CD8 lymphocyte counts and serum immunoglobulin A levels early in HIV infection as predictors of CD4 lymphocyte depletion during 8 years of follow-up.
abstract: OBJECTIVE
  To assess the ability of the CD8 lymphocyte count and immunoglobulin (Ig) A level, measured at the early stage of HIV infection when the CD4 lymphocyte count remains relatively high, to predict the future rate of CD4 lymphocyte loss and hence the risk of AIDS.
  
  
  METHODS
  Cohort of recently infected haemophiliacs with relatively high CD4 lymphocyte counts followed for up to 8.5 years from baseline measurement of CD8 lymphocyte counts and IgA levels.
  
  
  METHODS
  A regional haemophilia centre based in a major teaching hospital.
  
  
  METHODS
  Eighty-four of 111 patients with haemophilia who seroconverted to HIV between 1979 and 1985 in whom CD8 lymphocyte counts and IgA levels were measured soon after seroconversion (mean, 2.7 years; maximum, 5 years) while CD4 lymphocyte counts remained relatively high (median, 600 x 10(6)/l; minimum, 300 x 10(6)/l).
  
  
  METHODS
  Development of severe immunodeficiency defined by a CD4 lymphocyte count falling below 50 x 10(6)/l, and AIDS.
  
  
  RESULTS
  Individuals with high CD8 counts (P < 0.008) and high IgA levels (P < 0.003) at baseline experienced a more rapid rate of CD4 lymphocyte loss than those with low baseline levels. A score was derived to combine the predictive ability of CD8 count and IgA level. Estimated proportions with CD4 counts below 50 x 10(6)/l after 8 years of follow-up were 100, 30 and 14% for those with high, intermediate and low baseline scores, respectively. The CD8/IgA score showed similar ability to predict the future occurrence of AIDS (P < 0.0001; log-rank test).
  
  
  CONCLUSIONS
  Immune activation seen in HIV infection, as reflected by raised CD8 counts and IgA levels, appears to be linked to the process of CD4 lymphocyte depletion. Measurement of these markers in the years following infection, when CD4 lymphocyte counts remain high, provides a first indication of a patient's long-term prognosis.
authors.affiliation: Department of Public Health and Primary Care, Royal Free Hospital and School of Medicine, London, UK.
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: C A
authors.initials: CA
authors.lastname: Sabin
authors.forename: J
authors.initials: J
authors.lastname: Elford
authors.forename: M
authors.initials: M
authors.lastname: Bofill
authors.forename: C A
authors.initials: CA
authors.lastname: Lee
authors.forename: G
authors.initials: G
authors.lastname: Janossy
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000150:complications; D000293:Adolescent; D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D016827:CD8 Antigens / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005500:Follow-Up Studies; D005544:Forecasting; D015658:HIV Infections / Q000097:blood* / Q000150:complications; D006679:HIV Seropositivity / Q000097:blood / Q000150:complications; D006467:Hemophilia A / Q000150:complications; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000166:cytology*; D008875:Middle Aged; D016016:Proportional Hazards Models
chemical_list: D016827:CD8 Antigens; D007070:Immunoglobulin A