Bio-marker predicts rate of mental decline in Alzheimer's patients
By Brian Dodson
March 9, 2012
A new marker of Alzheimer's disease can predict how rapidly a patient's memory and other mental abilities will decline after the disorder is diagnosed, according to researchers at Washington University School of Medicine in St. Louis. Just released in Neurology were the results of a three-year long study that followed 60 patients with early Alzheimer's disease. The study found that rapid mental decline was predicted by the presence of larger levels of visinin-like protein 1 (VILIP-1) in the spinal fluid.
Part of the devastating effects of Alzheimer's disease is not knowing how rapidly or slowly the mental changes, memory loss, and eventually loss of personal identity will progress in your family member. Will you be able to celebrate your 50th wedding anniversary, or will it simply be a reminder of how much your and your spouse have lost? The general prognosis is known, but the rate at which the disease progresses varies widely from patient to patient, leaving both patient and caregivers in a sea of uncertainty.
In this study, patients with very mild or mild Alzheimer's disease were identified using an extensive battery of tests to assess their cognitive function. The researchers then measured VILIP-1 levels in the patient's spinal fluid. Cognitive testing was repeated yearly to provide data on rates of cognitive decay.
Two additional indicators were examined for predictive accuracy in the same study, the proteins amyloid beta and tau. They appear to reflect different aspects of the disease's progress. Changes in the amyloid beta and tau levels are associated with the formation of abnormal deposits of these proteins in the brain. VILIP-1 levels appear to reflect how much brain cell damage has actually occurred as the result of Alzheimer's.
In an earlier study, members of this research team showed that healthy subjects with high levels of VILIP-1 were more likely to develop cognitive impairment and Alzheimer's disease over a two- to three-year follow-up period. The predictive ability of measuring VILIP-1 levels thus appears to extend to healthy or presymptomatic individuals, as well as those who present with early Alzheimer's.
"Memory and other mental abilities declined faster in patients with the highest levels of VILIP-1," according to lead author Rawan Tarawneh, MD, now an assistant professor of neurology at the University of Jordan. "VILIP-1 appears to be a strong indicator of ongoing injury to brain cells as a result of Alzheimer's disease ... VILIP-1 seems to be at least as good as - and potentially even better than - the other prognostic indicators we used in the study. That could be very useful in predicting the course of the disease and in evaluating new treatments in clinical trials."