The test, called conformation-dependent immunoassay (CDI), was originally developed to detect various forms of disease-causing proteins called prions in cows, sheep, deer and other animals. In the new study, researchers led by Jiri Safar, M.D., Bruce Miller, M.D., Michael Geschwind, M.D., Stephen DeArmond, M.D., and Nobel Laureate Stanley B. Prusiner, M.D., of the University of California, San Francisco, found that CDI not only identifies prions in human brain tissue but is faster and far more precise than the standard immunological detection methods, which only detect a small fraction of the infectious prions that may be in the brain.
The finding appears in the March 1, 2005 issue of the Proceedings of the National Academy of Sciences, www.pnas.org. Two components of the NIH, the National Institute of Neurological Disorders and Stroke (NINDS)* and the National Institute on Aging (NIA), supported the study. Additional support was provided by the John Douglas French Foundation for Alzheimer's research, the McBean Foundation, and the Alzheimer's Disease Research Center of California.
"The findings of this NIH-funded research are an important step forward for the detection of prions," said Michael Nunn, Ph.D., NINDS program director for prion research. "It has been very difficult to generate diagnostic tests in this area and these results are a significant improvement for the diagnosis of CJD in living people."
In the study, Prusiner