International Diagnostics Centre and ASLM Convene Workshop on the Future of CD4 Testing for HIV

CD4 testing has been used to stage patients to determine when they should be put on antiretroviral therapy (ART), to assess their immune status, and to monitor patients once they have been put on ART, especially in situations where routine viral load (VL) testing is not available. VL testing – the measure of the number of HIV particles in a unit of blood – helps determine how effectively ART is working to kill the virus. VL testing used to be performed in laboratories using expensive equipment, but is now available as simple tests that can be performed at the point of care.

The World Health Organization (WHO) and other influential stakeholders have strongly recommended the scale-up of VL testing in resource-limited settings to increase access to monitoring the viral suppression of HIV+ patients on ART. In countries where CD4 testing has been a critical tool in the management of disease progression in HIV+ patients for many years, national programs are questioning the role of CD4 testing in patient management.

To address uncertainty around the continued utility of CD4 testing in the wake of changing international recommendations around HIV monitoring, the International Diagnostics Centre (IDC) at the London School of Hygiene & Tropical Medicine (LSHTM) and the African Society for Laboratory Medicine (ASLM) held a workshop on 4 December 2016 in Cape Town, South Africa. The workshop convened international stakeholders, including representatives from the WHO and US Centers for Disease Control and Prevention (CDC), country leaders and representatives from diagnostic companies.

“We come together tonight to find the right message to guide the HIV field on CD4 and viral load testing, in the interest of public health,” said Africa CDC Director Dr. John Nkengasong, who gave opening remarks.

At the workshop, speakers and participants shared their experiences and challenges related to the ongoing scale-up of VL testing. Many reiterated the continued importance of CD4 testing in the settings in which they work, stating that the issue is not a matter of either VL or CD4. However, given financial constraints, countries face difficulties in deciding how they can scale-up of VL testing over time while retaining CD4 testing. Participants emphasized the need for patient-centered support of HIV+ patients.

Nathan Ford of WHO, speaking at the event, stated, “CD4 is still the tool you want to measure the risk of opportunistic infections, disease progression and death.” He discussed the question of deciding when to use CD4 testing, stating that the scale-up of VL testing should not result in complete replacement and removal CD4 testing technologies.

At the end of the meeting, participants reinforced their belief in the ongoing importance of CD4 testing for people living with HIV, bringing forth diverse suggestions for balancing resource allocation for both CD4 and VL testing. Moving forward, the IDC will draft and circulate a meeting report, which will help to inform ongoing WHO guidance and in-country practice with respect to the appropriate use of CD4 testing and VL monitoring for HIV+ patients.