New AIDS Test Described as Fast, Accurate Developed by Scientists

A new test for the AIDS virus that reportedly is fast and accurate has been developed by researchers for the National Cancer Institute.

George Pavlakis, an institute researcher, said Thursday that he and Barbara Felber, another scientist, developed the test by using genetically altered human cells that react to the presence of the HIV virus by secreting an enzyme.

Pavlakis said the bioassay is so accurate it can detect 10 cells infected by the HIV virus, which causes AIDS, in a sample of more than a million unaffected cells.

Use of Bacterial Gene

Pavlakis said he and Felber developed the test by inserting a bacterial gene that produces an enzyme into a portion of the genetic pattern of the HIV virus. This recombined genetic pattern then was inserted into the genes of two types of human cells that are susceptible to HIV infection.

The result is that the engineered human cells now secrete the bacterial enzyme whenever the cells encounter an HIV infection.

By measuring the enzyme secreted by the test cells, Pavlakis said, the process tells if there has been an HIV infection and how active the virus has become.

He said the new test is only now being tested clinically and more experimentation must be performed before the technique is ready for hospital use.

Meanwhile, more than 700 laboratories across the country that perform tests for exposure to the AIDS virus will be evaluated following reports that some tests produced inaccurate or indeterminate results, federal health officials in Atlanta announced Thursday.

“This is an issue that needs to be addressed,” said Dr. James Allen, director for medical science in the AIDS program at the national Centers for Disease Control.

Lab Testing Defended

“We feel that overall the laboratory testing is not as bad as some people have been saying it is,” Allen said. “We’re talking about a minute fraction of 1% of people who may have been misclassified.”

The CDC said a nationwide “performance evaluation program” for detecting the antibody to the human immunodeficiency virus HIV is under way. More than 700 laboratories are being sent reference materials to be used in the study.

The CDC said that not all labs have been subjected to the scrutiny required to be licensed by the Food and Drug Administration.