There's only one sure way to know whether someone is suffering from a fatal neurodegenerative disorder that was linked last fall to "mad cow disease": Wait until the person dies, and look for the disease's trademark signs in a slice of brain tissue. Now, however, researchers have hopes of developing a test for the disease before it kills. A team of scientists reports in the 11 January issue of The Lancet that they have found an errant protein, thought to be responsible for the disease, in a victim's tonsils.
The find comes from the same team that last October announced evidence (see ScienceNOW, 23 October 1996) linking a new variant of Creutzfeldt-Jakob disease (vCJD)--which has killed 14 people in Britain and one in France since 1994--with bovine spongiform encephalopathy, as "mad cow disease" is formally known.
In its latest work, the group, led by John Collinge of Imperial College School of Medicine at St. Mary's Hospital, London, isolated protease-resistant prion protein, which has been linked to vCJD, from the tonsils of a 35-year-old woman who died after a 14-month illness featuring the disease's hallmark symptoms: loss of muscle coordination, memory loss, and dementia. Because physicians can easily scrape tonsil tissue from adults who still have theirs, such a test, the authors conclude, "may allow early clinical, or possibly preclinical, diagnosis of CJD."
"It's very interesting work," says Clarence Gibbs, a CJD researcher at the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland. But it's hard to say how useful such a test might be, he adds. For one thing, Gibbs points out, "there's no treatment for CJD," so a diagnosis currently does little to help disease victims. However, a test might help identify people who could be enrolled in drug trials, and it could shift the focus of concern in people with symptoms who test negative.