title: Impact of HIV-1 subtype on CD4 count at HIV seroconversion, rate of decline, and viral load set point in European seroconverter cohorts.
abstract: BACKGROUND
  Human immunodeficiency virus type 1 (HIV-1) subtype may influence disease progression. We compared CD4 lymphocyte cell count levels at seroconversion, decline rates and viral load set point in individuals infected with different HIV-1 subtypes.
  
  
  METHODS
  We used data from the Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) collaboration, restricted to those infected since 1996, aged ≥15 years, and applied mixed effects models for CD4 cell count decline and median regression for viral load set point (mean level 6-24 months from seroconversion).
  
  
  RESULTS
  The analysis included 3364 seroconverters with known HIV-1 subtypes. Compared with subtype B, CD4 at seroconversion was significantly higher for subtype CRF01 and lower for subtype C. Subsequent CD4 decline was significantly slower for subtypes A and CRF02 and marginally slower for subtype C compared with B. Mean CD4 loss at 2 years of seroconversion for white men exposed through sex between men, aged 30-39 years, having seroconverted since 2006, enrolled within 6 months of seroconversion, and without acute infection was 88, 142, 100, 130, 103, and 167 cells/µL for subtypes A, B, C, CRF01_AE, CRF02_AG, and G, respectively. In adjusted analysis, median viral load set point and time to clinical AIDS/death did not differ significantly by subtype, although all subtypes, except C, tended to have lower levels compared with B.
  
  
  CONCLUSIONS
  HIV-1 subtype significantly influences seroconversion CD4 cell levels and decline rates but not viral load set point. These findings may be helpful to HIV-positive individuals and their attending physicians in understanding disease progression.
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Athens University Medical School, Greece. gtouloum@med.uoa.gr
authors.forename: Giota
authors.initials: G
authors.lastname: Touloumi
authors.forename: Nikos
authors.initials: N
authors.lastname: Pantazis
authors.forename: Deenan
authors.initials: D
authors.lastname: Pillay
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Paraskevis
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Chaix
authors.forename: Heiner C
authors.initials: HC
authors.lastname: Bucher
authors.forename: Claudia
authors.initials: C
authors.lastname: Kücherer
authors.forename: Robert
authors.initials: R
authors.lastname: Zangerle
authors.forename: Anne-Marte Bakken
authors.initials: AM
authors.lastname: Kran
authors.forename: Kholoud
authors.initials: K
authors.lastname: Porter
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D005060:Europe / Q000453:epidemiology; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents