Alzheimer's Dianostic Test

Contributed by: Dennis Fortier, President, Medical Care Corporation
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Researchers at the University of Pennsylvania have published in the Annals of Neurology the development and standardization of a test to accurately diagnose Alzheimer's Disease (AD) by measuring the levels of beta-amyloid and tau protein in the spinal fluid. While many news stories are forwarded to me on a daily basis, this one has come to me in extraordinary abundance. My primary take on this news story is two-fold.

First of all, it is tremendously positive in the following sense. We are currently detecting patients with AD, on average, when they have end-stage pathology (up to 95% of patients are detected 8-10 years after the onset of symptoms according to published data). One of the reasons we intervene so late is that many physicians believe (erroneously) that a brain biopsy is the only reliable method of establishing a certain AD diagnosis. While it is true that a brain biopsy is one certain diagnostic method, following the published NINDS-ADRDA diagnostic criteria yields a very acceptable diagnostic accuracy rate of about 95%. Nonetheless, the presence of a lab test with high accuracy would increase physician comfort with the diagnostic process and hopefully lead to a more proactive attitude toward early intervention.

My second reaction is rooted in 20 years of experience commercializing health care technologies. The discovery of a scientific means to diagnose a given condition is a very early step on the long and often arduous path to making a product available. This scientific advance is absolutely positive but the practical implications of the discovery are many years away from helping real patients.