PCR-Based HIV Test Monitors Viral Load

BRANCHBURG, NJ--Roche Diagnostic Systems Inc.'s Amplicor H.I.V.-1monitor test for use in determining viral load in individualsinfected with HIV has received FDA approval for marketing. Thetest uses polymerase chain reaction (PCR) technology to measureHIV genetic material in the blood.

In laboratory studies, the Amplicor test was able in some casesto detect as few as 400 copies of HIV DNA in a blood sample andcould regularly detect 800 or more copies.

Two clinical trials of Amplicor were conducted in patients withadvanced HIV infection who had received no antiviral treatmentor treatment for less than 16 weeks. The results showed that highviral load before anti-HIV therapy, or large increases in viralload after treatment, correlated with increased risk of diseaseprogression to full-blown AIDS.