Researchers have identified changes in blood proteins that could help doctors track the effects of an Alzheimer’s drug called lecanemab, according to a study published in The Lancet Neurology. The work suggests a less costly alternative to repeated brain scans for monitoring treatment response.
Blood tests reveal complex protein patterns
Scientists at Washington University School of Medicine measured a wide panel of plasma proteins in patients receiving lecanemab during routine care. The panel covered markers of amyloid and tau pathology, inflammation, neurodegeneration and synaptic activity.
Results showed that some proteins, such as phosphorylated tau species and GFAP, shifted toward levels typical of cognitively healthy, amyloid-negative individuals. In contrast, amyloid-beta peptides rose above concentrations seen in the control group.
Other markers linked to inflammation, neuronal health and synaptic function moved further from the healthy reference range, while many proteins changed little. The authors note that a biomarker moving toward “normal” does not automatically indicate successful therapy, nor does a rise imply harm.
Increases in proteins associated with microglial activity may simply reflect the immune response that clears amyloid plaques. Consequently, the authors propose using a panel of readouts rather than a single score to capture distinct biological processes.
Implications for personalized monitoring
Among participants who later underwent follow-up amyloid PET, blood profiles differed between those who cleared plaques and those who retained detectable amyloid. This finding raises the possibility that future blood tests could signal when plaque removal has occurred, potentially reducing the need for immediate imaging.
A separate set of proteins correlated with changes in memory and thinking over time. Baseline levels of these markers might eventually help estimate an individual’s disease trajectory, beyond merely confirming that the drug engages its target.
Removing amyloid and preserving cognition appear related but biologically distinct goals. Separate blood signatures may be required to monitor drug engagement, plaque clearance, and downstream neuronal health.
While the study offers a step toward individualized monitoring, it remains exploratory. The cohort was drawn from a single center, was predominantly White, and only a subset received repeat imaging. Larger, more diverse studies are needed to validate the candidate proteins.
Leave a Reply