Time from human immunodeficiency virus seroconversion to reaching CD4+ cell count thresholds <200, <350, and <500 Cells/mm³: assessment of need following changes in treatment guidelines

Clin Infect Dis. 2011 Oct;53(8):817-25. doi: 10.1093/cid/cir494.


Background: Recent updates of human immunodeficiency virus (HIV) treatment guidelines have raised the CD4+ cell count thresholds for antiretroviral therapy initiation from 350 to 500 cells/mm(3) in the United States and from 200 to 350 cells/mm³ in mid- and low-income countries. Robust data of time from HIV seroconversion to CD4+ cell counts of 200, 350, and 500 cells/mm³ are lacking but are needed to inform health care planners of the likely impact and cost effectiveness of these and possible future changes in CD4+ cell count initiation threshold.

Methods: Using Concerted Action on Seroconversion to AIDS and Death in Europe data from individuals with well-estimated dates of HIV seroconversion, we fitted mixed models on the square root of CD4+ cell counts measured before combined antiretroviral therapy (cART) initiation. Restricting analyses to adults (age >16 years), we predicted time between seroconversion and CD4+ cell count <200, <350, and <500 cells/mm³ as well as CD4+ cell count distribution and proportions reaching these thresholds at 1, 2, and 5 years after seroconversion.

Results: Median (interquartile range [IQR]) follow-up for the 18495 eligible individuals from seroconversion while cART-free was 3.7 years (1.5, 7). Most of the subjects were male (78%), had a median age at seroconversion of 30 years (IQR, 25-37 years), and were infected through sex between men (55%). Estimated median times (95% confidence interval [CI]) from seroconversion to CD4+ cell count <500, <350, and <200 cells/mm(3) were 1.19 (95% CI, 1.12-1.26), 4.19 (95% CI, 4.09-4.28), and 7.93 (95% CI, 7.76-8.09) years, respectively. Almost half of infected individuals would require treatment within 1 year of seroconversion for guidelines recommending its initiation at 500 cells/mm³, compared with 26% and 9% for guidelines recommending initiation at 350 and 200 cells/mm³, respectively.

Conclusions: These data suggest substantial increases in the number of individuals who require treatment and call for early HIV testing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • CD4 Lymphocyte Count
  • Cohort Studies
  • Drug Administration Schedule
  • Drug Therapy, Combination
  • Early Diagnosis
  • Europe / epidemiology
  • Female
  • Follow-Up Studies
  • HIV Infections / drug therapy
  • HIV Infections / epidemiology
  • HIV Infections / immunology*
  • HIV Infections / virology
  • HIV Seropositivity / drug therapy
  • HIV Seropositivity / immunology*
  • HIV-1 / immunology*
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Practice Guidelines as Topic
  • Risk Factors
  • Sexual Behavior
  • Time Factors
  • United States / epidemiology