Low-cost Method of Measuring CD4+ Cells on Par with Flow Cytometry

A "Dynabeads" technique to enumerate circulating CD4+ T cells in HIV-infected patients may be an appropriate alternative to more expensive flow cytometry measurements, investigators report in the October 17th issue of AIDS.

Flow cytometry is the accepted standard method for counting CD4+ T cells, which is the best indicator of risk for opportunistic infections. However, the cost of the equipment, reagents and maintenance is often too high in developing countries.

Dr. Serge Diagbouga, of Centre Muraz, Bobo-Dioulasso, Burkina Faso, and colleagues compared flow cytometry results with those obtained by using magnetic beads coated with anti-CD4 monoclonal antibodies (Dynabeads; Dynal Biotech, Oslo, Norway) for 657 pairs of samples from five countries of West Africa.

In 89% of cases, both methods consistently classified patients at the threshold of 200 cells/µL, the authors note. The correlation coefficient for the two methods was 0.89 (p < 0.0004).

The coefficient of variation assessed in duplicate samples was 8.4% for the Dynabeads technique and 8.3% for flow cytometry.

"The implementation of this low-cost method was easy and successful in the West African context," Dr. Diagbouga and associates conclude.

10/22/03

AIDS 2003;17:2201-2208.