Oral exam: Process is as reliable as blood tests, authorities say
Americans got two new tests for the AIDS virus on June 3rd: one to more easily detect infection and the other to prevent how fast patients with the deadly diseas will sicken.
The Food and Drug Administration called Epitope Inc's Orasure the first oral test that appears as reliable as the standard blood test to diagnose the HIV virus that causes AIDS.
Orasure uses a treated cotton pad to scrape a tissue sample from between the gum and cheek. The sample is tested for antibodies to HIV. Doctors predict wide use by people at risk for HIV but who shunned blodd tests.
Patients who already know they're infected can find out just how much HIV is floating in their blood with Hoffman - La Roche's Amplicor test approved on June 3rd.
But the question is whether patients will want this test, said Dr. Curtis Scibner, FDA's deputy director of blood research.
Studies do show that patients with hih HIV blood levels are more liekly to sicken fast - but nobody knows if drugs that lower those blood levels significantly reduce the risk of death or even if changes in HIV amounts signal it's time to change treatments.
Cutting edge of science
"We are at the cutting edge of science and medicine right here," Scribner said. "We have not answered all of the possible questions, but other valuable information is becoming available everyday."
Still, Roche will offer baseline Amplicor testing for free to any HIV - infected patient for 60 days starting June 17th. If the test is completed at a later date, the cost will be approximately $150 to $200.
Doctors now gauge AIDS progression by measuring levels of an immune cell called CD4 that is a main target of HIV, However, it is not unusual for some people to have no AIDS symptoms despite very low CD4 levels.
meanwhile, the first generation of Orasure was approved in 1994. However, it used a less sensitive method to screen for HIV antibodies, called the ISA test.
In the past
people who tested positive then had to undergo a more sensitive blood test, called the Western blot, to be certain the deadly virus was present.
On june 3rd, the Food and Drug Administration approved the new version of Orasure that allows Western Blot testing of the oral sample instead of blood.
99.9% as accurate
Clinica trials showed the Orasure Western Blot test was 99.9 percent as accurate as the traditional blood test.
"It's exactly the same," said FDA's Scribner. " Many people don't like to get stuck for a blood sample, so in this case they could use an oral fluid sample."
The FDA approved the orginal less sensitive Orasure because doctors needed a way to reach people at risk of HIV but who shunned blood tests, Scribner explained. The theory was that a positive oral test would persuade such patients to accept a little blood - letting for confirmation that they were infected. "Now that confirmation can occur right on the oral fluids," he said.
An oral test is good for health workers, too, because they won't ruin the risk of sticking themsleves with the needle they just used on a possibly infected patient, explained Donna Sturgess of SmithKline Bleecham.
It will cost about the same as a blood test, which averages about $50 - $60, and doctors will receive the results within three days, she said.
Orasure is supposed to be used only by health care providers, but SmithKline and Epitroval for a home test.
Pacific Daily News from Washington DC (AP) 6/3/96
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