FDA OKs Fast, Easy HIV Test
 

Test Should Benefit High-Risk People, Emergency Workers
By Jim Kling
Reviewed By Michael Smith, MD
WebMD Medical News



Nov. 7, 2002 -- A new simple, rapid, and accurate HIV test could make it much easier for people to get tested, even away from traditional testing centers such as hospitals and clinics.


Today, the FDA announced approval of the OraQuick Rapid HIV-1 Antibody Test, manufactured by OraSure Technologies, Inc.


It generates a result that is greater than 99% accurate within 20 minutes after collecting a drop of blood with a simple pinprick. That rapid turnaround time is good news for doctors who have been frustrated by current tests that can take as many as 14 days to complete. The delay creates a tendency for people to come in for an HIV test but then skip the later appointment, never learning their HIV status.


It is estimated that some 8,000 people per year fail to return to see their results. Moreover, of the estimated 900,000 people infected with HIV in the United States, as many as one quarter of them, or 225,000 people, may be unaware that they carry the virus.


"As someone who has been in the trenches fighting this disease, I can tell you (the waiting period for test results) is a real psychological problem," said Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases.


Someone who is at high risk of infection may work up enough courage to go in for initial testing, but days or weeks of uncertainty may be too traumatic for them to see the results. Just as important as the 8,000 or so people who do not show up for follow-up appointments are the many who never go in for testing in the first place. The new test should "provide the heightened fortitude of knowing you're going to get an answer" right away, said Fauci in a news conference.


The benefits of the new test should extend beyond high-risk patients to infants and even emergency workers. Pregnant women at high risk of infection could be tested quickly when they arrive in hospital ready to give birth, and if the test comes up positive there is an arsenal of drugs available that can reduce the odds of transmission to the child.


Emergency workers who are accidentally punctured by a needle used on a patient need to know right away if the patient is infected. If there is any doubt, the worker will go on a regimen of anti-HIV drugs in hopes of preventing infection, but these drugs can have serious side effects of their own. A 20-minute test on the patient could prevent a lot of stress and trouble.


The new test is also simple enough that it has the potential to be used away from hospitals and clinics. Before that can happen, however, it must be approved under the Clinical Laboratory Improvements Amendments of 1998 (CLIA), which certifies that the test is simple and safe enough to perform that it can be used under more diverse settings, perhaps even by social workers. "I strongly encourage OraSure" to apply for CLIA approval, said Health and Human Services Secretary Tommy G. Thompson in a news conference.


But even with its potential wide use, the test suffers from the same limitation as any antibody-based test. The human body does not begin to make antibodies to the HIV virus immediately upon infection. Instead, it can take up to three months before antibodies are detectable by blood test. Before that, an antibody-based test would come up negative even in the presence of an HIV infection. "If you engage in risky behavior and then immediately run out to get this test, it won't help you," said Murray Lumpkin, MD, principal deputy commissioner of FDA, also at the news conference

Protein in monkeys may block HIV
 

Finding may lead to treatment to prevent infection in people

Oregon Health and Science University / AP

The Associated Press

Updated: 4:11 p.m. ET Feb. 25, 2004

Scientists say they’ve discovered how some monkeys resist infection with the AIDS virus, a finding that might lead to a treatment that blocks HIV in people.

Researchers found that once HIV enters monkey cells, it encounters a protein that stifles its attempts to replicate. That stops the virus from spreading in the animal.

“This is really important because it will help build a basis for hammering the virus before it gets started,” said Paul Luciw, a University of California at Davis microbiologist who specializes in AIDS research.

‘We expect that now that we’ve identified this protein factor, it is likely we’ll find ways to manipulate it and increase its potency.’

The protein, called TRIM5-alpha, was identified in rhesus macaques by a team of Harvard researchers at the Dana-Farber Cancer Institute in Boston. It’s not clear exactly how the protein acts against HIV, said Dr. Joseph Sodroski, who led the Harvard study published Thursday in the journal Nature.

Humans have their own version of TRIM5-alpha, but it’s not as effective as the monkey version in countering HIV. However, researchers may be able to design a drug that makes it work better, Sodroski said.

“We expect that now that we’ve identified this protein factor, it is likely we’ll find ways to manipulate it and increase its potency,” Sodroski said, “and we hope to stimulate our own natural resistance to HIV by doing so.”

The mechanism may even work against other viruses, he said.

“What we’re really uncovering is the first example of a natural system of defense that may be operating against other viruses besides HIV,” Sodroski said. “We’re looking at ’example one’ here, and I highly doubt it will be the only example in nature.”

How protein blocks virus
Normally, HIV enters a cell and hijacks its “factory” for making proteins. It orders the machinery to churn out proteins to make new copies of HIV, which then leave to infect other cells.

The monkey protein blocks this process, apparently by interfering with HIV’s attempts to remove the coating that surrounds its genetic material, researchers said. This coating must be shed before HIV can insert its genetic material into the cell’s own DNA, a key step in replication.

The Nature study could help researchers test the effectiveness of a potential HIV vaccine on animals now that scientists have a better understanding of why monkeys resist the disease, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Little is known about the family of proteins that includes TRIM5-alpha, said Stephen Goff, a Columbia University biochemist.

But the Harvard study suggests there are probably many virus-resistant proteins “that act at different stages in the viral life cycle, and these are only in the last few years coming to light,” Goff said.

“Gradually now, they’re being identified and hopefully they will be understood in terms of how they work,” Goff said.

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