Lipid Metabolism May Be Used as a Predictive Test for Alzheimer’s Disease

According to an article published in the Journal of Alzheimer’s Disease (2016;50(3):887-894), biochemical changes in the blood in the rare, inherited form of Alzheimer’s disease, known as familial Alzheimer’s disease, have been identified by researchers in Australia. The identification of lipid variations may lead to a method for diagnosing all forms of Alzheimer’s disease before it can cause significant damage to the brain. 

The team, led by Ralph Martins, PhD, from the Clinical Research Center for Mental Health and Edith Cowan University, Australia, examined the lipid profiles of 20 people who carry a mutation associated with familial Alzheimer’s disease. Researchers used samples from the Dominantly Inherited Alzheimer Network (DIAN) study and found that people who carried the mutation also had altered levels of specific lipids in their blood plasma compared with those in a control group.

The researchers measured levels of 139 plasma phospholipid and sphingolipid species. Significantly altered species in mutation carriers compared to non-carriers primarily belonged to choline and ethanolamine containing phospholipid classes and ceramides. Furthermore, the presence of phosphatidylcholine species (34:6, 36:5, 40:6) were significantly correlated with levels of tau protein in cerebrospinal fluid (P  <  0.05), and, within the mutation carrier group, the presence of plasmalogen ethanolamine species (34:2, 36:4) correlated with both levels of tau protein in cerebrospinal fluid and amyloid protein load in the brain (P <  0.05).

The alterations to phospholipid and sphingolipid metabolism in familial Alzheimer’s disease provide insight into the pathomolecular changes occurring within the disease pathogenesis. Further, findings reported in this study allow comparison of lipid alterations in familial Alzheimer’s with those reported previously in sporadic Alzheimer’s disease. 

Along with previously published studies on lipids in the most common form of Alzheimer’s disease, this pilot study suggests that specific changes in lipid metabolism may be used as a predictive test for Alzheimer’s disease. However, the authors urged caution due to the pilot nature of the study, suggesting that their findings warrant validation in the larger DIAN cohort.—Amanda Del Signore