Abbott and Celera, an Applera Corporation business, has received US Food and Drug Administration (FDA) approval to market the Abbott RealTime HIV-1 viral load test for use on the company's m2000 automated instrument system.

The Abbott RealTime HIV-1 assay, for use on the new m2000 system, is designed to detect and precisely measure levels of the human immunodeficiency virus (HIV) circulating in a patient's blood (viral load), including the three major groups of HIV-1 as well as non-B subtypes. The test is intended for use as a marker of disease prognosis and an aid in assessing viral response to antiretroviral treatment.

"As the viral diversity of HIV-1 continues to increase, the need for highly sensitive tests to monitor patient response to antiviral therapies becomes even more important," said John Robinson, Ph.D., senior director, research and development, Abbott Molecular. "The reliability and precision of the Abbott RealTime HIV-1 test on the m2000 system for detecting HIV-1 subtypes across a broad dynamic range should help physicians be confident about assessing viral levels in their patients, enabling them to provide optimal treatment."

HIV-1 can be divided into groups M (major), O (outlier) and N (new). The vast majority of isolates cluster in the M group. Distinct lineages within group M have also been identified, and these lineages are called strains or subtypes. They include subtype designations A through G. While HIV-1 subtype B continues to be the most common strain found in the United States, studies suggest that an increasing number of newly diagnosed patients are infected with non-B subtype viruses and various circulating recombinants as a result of the influx of immigrants from countries where variant strains of HIV are more common. In a recent study published in the Journal of Medical Virology1 examining the impact of this phenomenon on Minneapolis-based Hennepin County Medical Centre, the predominant HIV subtypes identified by the hospital in African-born patients were subtype C (40%), followed by A (20-25 %), D (10 %) and G (3-5 %).

Another recent study by the Centres of Disease Control and Prevention involving more than 3,000 HIV patients in the United States found that 5.1 percent of those patients were infected with HIV-1 non-B subtypes.

"The ability to detect and measure each of these genetic variations of the virus is an important factor in managing the disease on a worldwide basis and determining the most effective course of treatment for patients," said Timothy Stenzel, M.D., medical director, Abbott Molecular.

The RealTime HIV-1 test has been developed for use on the Abbott m2000 system, an automated instrument for DNA and RNA testing in molecular laboratories. The m2000 system is based on real-time polymerase chain reaction (PCR) technology and is designed to efficiently detect and measure life-threatening viruses and bacteria in patient samples in less than five hours, compared to other testing methods that may take up to two days.

Additional products in development for the Abbott m2000 system include assays for hepatitis C virus (HCV), hepatitis B virus (HBV), HCV genotyping, chlamydia and gonorrhea. Abbott markets the m2000 system and a menu of tests throughout the world as part of a strategic alliance with Celera.

"We're very pleased that Abbott, through its alliance with Celera, has secured FDA approval on a real-time viral load assay for HIV," said Kathy Ordoñez, president, Celera. "Today, more than 2 million HIV viral load tests are performed annually in the United States, and we believe both the Abbott RealTime HIV assay and the m2000 system offer substantial productivity and performance advantages to customers performing these tests."

The Abbott RealTime HIV-1 assay, for use on the m2000 system, is among the most sensitive viral load tests available today, with a broad dynamic range, capable of quantitating HIV-1 in plasma down to as few as 40 RNA molecules per milliliter (mL) and up to as many as 10 million molecules per mL.