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Updated: Aug 19, 2026
Comprehensive & Cost Effective Laboratory Monitoring of HIV/AIDS: an African Role Model
Published on: October 31, 2010
CD4 and total lymphocyte counts as predictors of HIV disease progression
1Department of Medicine, University of Cape Town Medical School, South Africa.
Insights
Total lymphocyte count (TLC) is a cost-effective predictor of HIV progression, similar to CD4 counts. A TLC below 1250/microliter indicates increased risk and may warrant cotrimoxazole prophylaxis.
Area of Science:
- Infectious Diseases
- Immunology
- Public Health
Background:
- CD4+ T-lymphocyte (CD4) counts are standard HIV markers but are expensive.
- Total lymphocyte counts (TLC) are widely available and a potential low-cost alternative.
Purpose of the Study:
- To compare CD4 counts and TLC as predictors of AIDS or death in HIV-positive patients.
- To evaluate TLC as a potential indicator for initiating cotrimoxazole prophylaxis.
Main Methods:
- Longitudinal study of 831 HIV-positive outpatients.
- Comparison of CD4 counts and TLC as predictors of disease progression, AIDS, and mortality.
- Analysis of TLC thresholds (<1250/microliter) in relation to specific opportunistic infections.
Main Results:
- CD4 counts and TLC were found to be equal predictors of disease progression.
- A TLC < 1250/microliter predicted similar survival rates to CD4 counts < 200/microliter.
- TLC < 1250/microliter preceded Pneumocystis pneumonia or cerebral toxoplasmosis in 76% of patients.
Conclusions:
- TLC is a viable, cost-effective alternative to CD4 counts for monitoring HIV progression.
- A TLC < 1250/microliter can serve as an indicator for starting cotrimoxazole prophylaxis in HIV patients.
Abstract:
CD4+ T-lymphocyte (CD4) counts are a standard laboratory marker of disease progression in HIV infection, but expense precludes their use in large parts of the world. Total lymphocyte counts (TLC), in contrast, are widely available. We compared CD4 and TLC counts as predictors of developing AIDS or death in 831 HIV-positive out-patients (582 males and 249 females with both homosexual (males, n = 316) and heterosexual (n = 515) transmission patterns. The first CD4 count < 200/microliter and first TLC < 1250/microliter predicted similar (p = 0.52) survival, irrespective of clinical stage. For each clinical stage, a significant difference in progression to AIDS and mortality was predicted by TLC above or below 1250/microliter (p < 0.03). Survival and progression to AIDS occurred at similar rates in patients with a TLC < 1250/microliter or a CD4 count < 200/microliter (p > 0.1), and patients with a TLC > 1250/microliter or a CD4 count > 200/microliter (p > 0.5). A TLC < 1250/microliter preceded the development of Pneumocystis carinii pneumonia or cerebral toxoplasmosis in 76% of patients. In this longitudinal study, TLC and CD4 counts were equal predictors of disease progression. A TLC < 1250/microliter could be considered an indication for commencing cotrimoxazole prophylaxis.
