David, This new assay should go a long ways toward getting a quicker read on PI resistance. I suspect that many relapsed patients never saw their counts go below 50 copies. The current assay only goes to 500 copies:
Ultrasensitive HIV RNA Assay Expected Soon
WESTPORT, Oct 14 (Reuters) - This summer Roche Diagnostic Systems, based in
Nutley, New Jersey, submitted an application to the Food and Drug Administration for
approval of a new "Ultrasensitive Method Test" to measure HIV RNA load, according
to an article in the October issue of AIDS Alert.
The new assay, which has already been used as a research tool for more than a year,
has a sensitivity down to 50 copies/mL. Although a more sensitive assay for viral load
has obvious advantages in clinical trials, the article continues, the role of the new test in
patient management is not as clear.
The availability of a more sensitive test could initially create widespread confusion, Dr.
Michael Saag of the University of Alabama in Birmingham pointed out. For example,
the clinical significance between having a viral load of 50 copies and 400 copies for
patients on protease inhibitors is unknown. According to Dr. John Mellors of the
University of Pittsburgh, the difference could be significant. "My personal view is the
we should aim for zero copies," he said.
Roche is also developing a DNA assay--the only way to confirm that the AIDS virus
as been completely eradicated, according to Dr. John Sninsky, Roche Diagnostic's
senior director of research. The DNA assay is now being tested in several small US
and European trials.
-Westport Newsroom 203 319 2700 |
