A Semiquantitative Microassay for Measurement of Relative Number of Blood Mononuclear Cells Infected with Human Immunodeficiency Virus

A simple semiquantitative microassay was developed for the measurement of relative number of infected peripheral blood mononuclear cells (PBMC) from individuals infected with human immunodeficiency virus (HIV). The assay is based on cocultivation of serially diluted PBMC of a seropositive person with phytohemmagglutinin-stimulated normal PBMC. The microassay has comparable sensitivity with the standard virus culture method in detecting positive HIV cultures. Since the microassay uses only 2-3 × 10⁵ patients' PBMC, the assay is also most suitable for HIV isolation from HIV-infected infants or from AIDS patients with extremely low T-cell counts. The microassay can also be used to measure antiviral effects of a drug on persistent HIV infection in vitro. Because the microassay measures the relative number of infected PBMC, it can be readily used for following the quantitative antiviral effect of a drug in a clinical trial.