Building a Better 'Mad Cow' Test
"There is no simple diagnostic test for people, so we have no idea how many are infected," says pathology professor and mad cow expert Witold K. Surewicz, PhD, of Case Western Reserve University in Cleveland, Ohio. "Routine testing just isn't possible. And the process of testing cattle is also complicated. This is a pretty exciting finding which could lead to an easier and much more accurate test."
Writing in the March issue of the journal Nature Medicine, researchers from Scotland's Roslin Institute demonstrated that a protein known as erythroid differentiation-related factor (EDRF) might be overproduced in people when they contract transmissible spongiform encephalopathies such as mad cow disease. Perhaps, the researchers suggest, it may be possible to design a test for EDRF, with higher than normal levels of the protein being an indicator of likely infection.
In an editorial that appears in the same issue, Aguzzi points out that several basic questions must be answered before we'll know if EDRF will in fact be a good diagnostic marker.
For instance, he says, it is not currently known if overproduction of the protein is unique to transmissible spongiform encephalopathies, or if the same thing happens in other diseases. Researchers also must establish what a normal level of EDRF is in healthy, noninfected people.
"With all the attention being paid to this issue, and the desire for a blood test to find this infection, these questions should be answered very quickly," Aguzzi says.
Surewicz agrees and adds that these findings, while exciting, are very preliminary.
"I am certain the research will get done, because we are all desperate to find a simple test," he says. "Even if these findings turn out to be less than significant, I feel certain that there will be a simple diagnostic test. I just can't say when."