Noninvasive Tool Diagnoses AD, Differentiates From Lewy Body Dementia

A new study has found that an inexpensive and minimally invasive diagnostic tool that uses infrared light to analyze blood plasma can effectively diagnose and differentiate Alzheimer disease from and other types of dementia.

In their study, the researchers used attenuated total reflection (ATR-FTIR) spectroscopy combined with chemometric techniques to analyze blood plasma samples collected from 549 individuals: 347 diagnosed with various neurodegenerative diseases, such as Alzheimer disease (AD), Parkinson disease, and progressive supranuclear palsy, and 202 age-matched, healthy individuals.

Overall, ART-FTIR spectroscopy was able to identify AD in 164 individuals with a sensitivity and specificity of 70%. After the researchers included information on the apolipoprotein ε4 genotype (APOE ε4) into their analysis, the sensitivity and specificity increased to 86% for individuals who carried 1 or 2 alleles of ε4 and to 72% sensitivity and 77% specificity for individuals who did not carry ε4. In addition, the diagnostic test identified early cases of AD in 14 individuals, and had a sensitivity of 80% and specificity of 74% for early AD.

Furthermore, the test was able to differentiate AD from dementia with Lewy bodies in 34 individuals with a sensitivity and specificity of 90%.

“Our method allows for both rapid and robust diagnosis of neurodegeneration and segregation between different dementias,” the researchers concluded.

—Melissa Weiss

Reference:

Paraskevaidi M, Morais CLM, Lima KMG, et al. Differential diagnosis of Alzheimer’s disease using spectrochemical analysis of blood [published online before print September 5, 2017]. Proc Natl Acad Sci U S A. doi:10.1073/pnas.1701517114.