title: Changes over time in post-seroconversion CD4 cell counts in the Italian HIV-Seroconversion Study: 1985-2002.
abstract: OBJECTIVE
  To determine whether there has been a tendency for early post-seroconversion CD4 cell counts to change over calendar time.
  
  
  METHODS
  A prospective cohort study of individuals with well-estimated dates of seroconversion.
  
  
  METHODS
  We studied 1251 individuals who seroconverted to HIV in Italy between 1985 and 2002, and for whom the first CD4 count was measured within 2 years of seroconversion and before any use of antiretrovirals. Linear regression models were used to assess evidence for a trend in post-seroconversion CD4 cell count over time.
  
  
  RESULTS
  The median post-seroconversion CD4 cell count was 674 x 10 cells/l in those seroconverting between 1985 and 1990, 588 x 10 cells/l for 1991 to 1994, 559 x 10 cells/l for 1995 to 1998 and 494 x 10 cells/l for 1999 to 2002. The post-seroconversion CD4 cell count decreased by an average of 8.4 x 10 cells/l per year (95% confidence interval, 4.0-12.9; P < 0.001), after adjustment for potential confounders, including interval between HIV-negative and HIV-positive tests, lag time for first CD4 cell count measurement, age at seroconversion, gender, HIV-transmission group, and clinical centre. The finding was consistent in sensitivity analyses restricted to those with information on acute infection.
  
  
  CONCLUSIONS
  These data suggest a possible decreasing trend in CD4 cell count immediately following seroconversion in Italy which requires further investigation.
authors.affiliation: Reparto di Epidemiologia, Dipartimento di Malattie Infettive, Parassitarie e Immunomediate, Istituto Superiore di Sanità, Rome, Italy. marie.dorrucci@iss.it
authors.forename: Maria
authors.initials: M
authors.lastname: Dorrucci
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Phillips
authors.forename: Benedetta
authors.initials: B
authors.lastname: Longo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rezza
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000276:immunology; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D004812:Epidemiologic Methods; D005260:Female; D006679:HIV Seropositivity / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged