When testing is not possible

Several solutions have been forwarded to address the problem of CD4 cell count cost and lack of laboratory facilities and/or equipment in resource-limited areas.

Researchers working with a cohort of nearly 1200 patients from the University of Alabama at Birmingham observational database designed a decision tree based on local circumstances to see if it could more reliably identify patients with fewer than 200 cells/mm3 than did the surrogate of a total lymphocyte count (TLC) of 1200 cells/ml (the WHO-recommended cut point for initiating ARV therapy).

Variables included TLC, haemoglobin, platelet count, gender, body mass index, and ARV treatment use in the past month. A similar decision tree, developed using local circumstances, was also tested in Zambia with data from a cohort of nearly 600 female patients.1

Using a decision tree algorithm to identify low CD4 cell counts was more effective than using the TLC cut point of 1200 cells/ml in any single population. Further, in Zambia, a custom-designed decision tree was more effective than one developed using data from a different population. The use of inexpensive, easily obtained variables were relevant, regardless of whether the patient was receiving antiretroviral treatment or not. The variables TLC, haemoglobin, and platelet count were significant.

The authors suggest that since different areas have their own local laboratory baseline reference values (resulting from genetic, environmental, infectious, or nutritional factors), additional studies should be done to see whether local models could be developed for different populations and their use considered alongside the recommended surrogate of a TLC limit of 1200 cells/ml.

The DART study looked at clinical outcomes in the absence of routine laboratory monitoring by randomising over 3000 antiretroviral-naive patients in Uganda and Zimbabwe to receive clinically driven monitoring alone or both laboratory and clinical monitoring. Patients were followed for nearly five years.

Investigators found that clinical monitoring alone was sufficient for the first two years of treatment and that CD4 count monitoring could be deferred until after that period. If patients on the clinical monitoring arm experienced a WHO stage 4 clinical event, their ART regimen was changed. After five years of treatment, survival in the clinical monitoring arm was 87 versus 90% in the laboratory and clinical monitoring arm.2 3 


  1. Chen R et al. Complete blood cell count as a surrogate CD4 cell marker for HIV monitoring in resource-limited settings. J Acquir Immune Defic Syndr 44 (5): 525-530, 2007
  2. Mugyenyi P et al. Impact of routine laboratory monitoring over 5 years after antiretroviral therapy (ART) initiation on clinical disease progression of HIV-infected African adults: the DART Trial final results. Fifth International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention, Cape Town, abstract TuSS103, 2009
  3. Medina-Lara A et al. Cost effectiveness analysis of routine laboratory or clinically driven strategies for monitoring antiretroviral therapy in Uganda and Zimbabwe (DART Trial). Fifth International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention, Cape Town, abstract TuSS104, 2009
Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.