Dr Ananya Mandal, MD
In a new development, Alzheimer’s disease can now be predicted with up to 100 percent accuracy several years before its onset using three special marker proteins present in the spinal fluids. The study was published in the American Medical Association’s Archives of Neurology.
Geert De Meyer of Ghent University in Belgium and colleagues in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) analyzed data from 114 older adults who were cognitively normal, 200 who had mild cognitive impairment and 102 who had Alzheimer’s disease for the study. They found a specific biomarker signature that is present in more than 90 percent of the Alzheimer’s group, 72 percent of those with mild cognitive impairment and 36 percent of those who were cognitively normal. They checked the data on two other smaller groups. In one of the groups, 64 of 68 or 94 percent of the group were “correctly classified with the Alzheimer’s disease feature,” the authors of the study wrote. 57 patients with mild cognitive impairment who were followed up for five years there was a 100-percent accurate prediction of progression to Alzheimer’s disease.
Authors wrote, “The initiation of the Alzheimer’s disease pathogenic process is typically unobserved and has been thought to precede the first symptoms by 10 years or more.” The presence of the biomarkers suggested to the researchers that “Alzheimer’s disease pathology is active and detectable earlier than has heretofore been envisioned.”
According to an editorial by Dr. John Growdon, a neurology professor at Massachusetts General Hospital, in the journal issue, the test was accurate and applicable but, “Whether it is noninvasive or not is in the eye of the beholder: performing a lumbar puncture is no more invasive than other outpatient procedures such as endoscopies that millions of Americans tolerate each year.” The editorial however was “strongly commending CSF [cerebrospinal fluid] analyses of A1-42, T-tau, and P-tau in circumstances where having a definitive diagnosis of AD is important for counseling patients about such concerns as work, driving, and making other lifestyle changes.”
Maria C. Carrillo, senior director of medical and scientific relations at the Alzheimer’s Association said, “This just reinforces the recommendation by [Alzheimer's working groups] saying that biomarkers can actually be incorporated today into clinical practice in order to add a certain piece to the diagnosis if patients are already presenting with something that looks like Alzheimer’s.”
This marker may have more immediately utility in clinical trials, as a way to determine if drugs-in-process are actually effective.