Can a blood test predict Alzheimer's? Researchers say yes … sort of.
According to a 525-person study by Howard J. Federoff Md, PhD, of Georgetown University and colleagues, the levels of ten unconventional plasma phospholipid molecules when used as markers helped to differentiate between initially healthy people over 70 who then developed Alzheimer's disease compared with those that did not.
In a statement Federoff said, "We consider our results a major step torward the commercialization of a preclinical disease biomarker test that could be useful for large-scale screening to identify at-risk individuals."
However, MedPage Today editor John Gever noted that this might be an overly optimisstic assessment when one considers the data. He writes that "if the study cohort's 5 percent rate of conversion from normal cognition to mild impairment or Alzheimer's disease is representative of a real-world screening population, then the test would have a positive predictive value of just 35 percent."
In other words, two-thirds of the time the screening would produce a false-positive result. A positive predictive value of 35 percent is wildly below the generally accepted minimum standard for positive predictive values for any screening test of people who are not at-risk, which is 90 percent.
On the plus side however, is the use by this research team of marker that are unrelated to the APOE gene or to beta-amyloid and tau proteins, suggesting a potential new direction for research in this field.
The team's findings appear in the most recent issue of Nature Medicine.
Source: MedPage Today