Stability of infectious HIV in clinical samples and isolation from small volumes of whole blood.

To evaluate the stability of infectious HIV in clinical samples and the efficiency of isolating it from small volumes of whole blood. Titres of infectious HIV were measured in peripheral blood mononuclear cells and plasma 2, 24, and 48 hours after peripheral blood had been collected from 10 HIV positive adult volunteers. Volumes of whole blood (1 ml to 5 microliters), collected from a further five volunteers, were used to determine the minimum volume from which HIV could be isolated. Infectious HIV was isolated by co-culture with phytohaemagglutinin stimulated umbilical cord mononuclear cells. Geometric mean titres of infectious HIV seemed to be more stable in peripheral blood mononuclear cells than in plasma. HIV was recovered from all 10 peripheral blood mononuclear cell samples during the 48 hours after sample collection, but from only four plasma samples. HIV could occasionally be isolated from 5 microliters of whole blood and reliably from 200 microliters. HIV can be isolated from peripheral blood mononuclear cells and plasma for up to 48 hours after sample collection. Isolation of HIV from small volumes of whole blood has applications for the diagnosis and management, of HIV positive children.