HIGH-RATE OF HIV ISOLATION FROM PLASMA OF ASYMPTOMATIC PATIENTS THROUGH POLYETHYLENE-GLYCOL (PEG) TREATMENT

The usefulness of traditional methods of HIV plasma titration has been limited by poor detection capacity in the asymptomatic phase of HIV d isease. We analyzed plasma samples from asymptomatic seropositive or e arly symptomatic patients, comparing the classic plasma culture method with the following techniques: phorbol 12-myristate 13-acetate treatm ent of target cells, centrifugal inoculation of the virus, heat treatm ent of cultures, addition of monocyte/macrophages to cultures, and pol yethylene glycol (PEG) treatment of the plasma. Only PEG treatment sig nificantly increased the percentage of HIV isolation. The increase of HIV isolation after PEG treatment is more evident in patients with hig her CD4(+) cell counts and those without detectable levels of p24 anti gen. In the p24-negative samples, HIV was isolated in 17 of 24 (71%) w ith PEG treatment versus nine of 24 (37%) with the classic method (p < 0.01). A number of discordant samples were found using the classic an d PEG methods. Combining the positive results obtained with either tec hnique, we obtained an overall HIV detection rate of 76%. The increase d sensitivity of the combination of PEG and classic methods may allow a wider use of plasma viremia as part of the virological evaluation of anti-HIV drug efficacy in asymptomatic patients.