CD4 Count and the Risk for Death in Patients Infected With HIV Receiving Antiretroviral Therapy

Ann Intern Med. 1991 Aug 1;115(3):184-9. doi: 10.7326/0003-4819-115-3-184.


Objective: To investigate the relation between CD4 count and the immediate hazard of dying in patients receiving zidovudine (azidothymidine [AZT])-based antiretroviral therapy.

Setting: A research hospital that recruits patients from the entire United States.

Design: Retrospective analysis of a cohort of patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex participating in long-term zidovudine-based antiretroviral protocols.

Patients: Fifty-five patients with human immunodeficiency virus (HIV) infection and either AIDS or severe AIDS-related complex who were followed for as many as 4 years while they received antiretroviral therapy.

Measurements: CD4 counts were measured.

Main results: Ten patients are known to be alive and 1 was lost to follow-up. Of the 44 patients who are known to have died, the CD4 range was known within 6 months of death in 41. All but 1 of these 41 assessable deaths occurred in patients whose CD4 counts were known to have fallen below 50 CD4 cells/mm3 (P less than 10(-10)). The hazard of dying in the cohort ranged from 0 deaths/patient-month (95% CI, 0 to 0.008 deaths/patient-month) in patients with 200 or more CD4 cells/mm3 to 0.07 deaths/patient-month (CI, 0.050 to 0.094 deaths/patient-month) in patients with fewer than 50 CD4 cells/mm3. For the patients who died and whose cases were assessable, the mean of the last three CD4 counts obtained before death was 7.7 CD4 cells/mm3 (CI, 0.9 to 63.3 cells/mm3). The median survival of patients once their CD4 counts fell below 50 CD4 cells/mm3 was 12.1 months (CI, 7.2 to 19.4 months).

Conclusions: In a carefully followed cohort treated with zidovudine-based antiretroviral therapy, nearly all deaths occurred in patients with fewer than 50 CD4 cells/mm3. These findings may have implications in the monitoring of patients with AIDS and in the use of CD4 count as a clinical trials end point for the antiretroviral therapy of HIV infection.

Publication types

  • Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • CD4-Positive T-Lymphocytes*
  • Confidence Intervals
  • Drug Evaluation
  • Follow-Up Studies
  • HIV Infections / drug therapy
  • HIV Infections / immunology*
  • HIV Infections / mortality*
  • Humans
  • Leukocyte Count*
  • Pilot Projects
  • Proportional Hazards Models
  • Risk Factors
  • Survival Analysis
  • Time Factors
  • Zidovudine / therapeutic use*


  • Zidovudine