Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

What was studied?

This original research study investigated whether the metallomic signature of dementia with Lewy bodies (DLB) differs from Alzheimer’s disease (AD) and Parkinson’s disease dementia (PDD). The study sought to determine if post-mortem changes in elemental concentrations—particularly in essential metals—could help differentiate these often-overlapping neurodegenerative conditions. Using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS), the authors quantified concentrations of nine elements (Na, Mg, K, Ca, Mn, Fe, Cu, Zn, and Se) across 10 brain regions from DLB patients and age-/sex-matched controls. These findings were directly compared to previously published metallomic profiles for AD and PDD, produced using identical methodologies. Multivariate analyses (PCA and PLS-DA) were employed to assess the potential for disease discrimination based on metal signatures.

Who was studied?

The study analyzed post-mortem brain tissue from 23 DLB patients and 20 controls, collected across ten distinct brain regions. Comparative analyses included prior datasets from similarly matched AD and PDD patient cohorts.

What were the most important findings?

In this study, region-specific metallomic signatures profiling revealed distinct trace element alterations in Dementia with Lewy Bodies (DLB). Copper (Cu) levels were consistently decreased in five of ten DLB brain regions, including the cingulate gyrus (CG), middle temporal gyrus (MTG), primary visual cortex (PVC), substantia nigra (SN), and putamen (PUT), suggesting a widespread Cu deficiency. Sodium (Na) was elevated in four regions—medulla (MED), cerebellum (CB), MTG, and CG—while more localized changes were observed for other metals. Iron (Fe) levels were increased in the motor cortex (MCX) and CG, whereas manganese (Mn) was decreased in both the PVC and MED. Calcium (Ca) was specifically reduced in the hippocampus, and selenium (Se) was also decreased in the PVC.

No significant differences in magnesium, potassium, or zinc levels were observed between DLB and control brains. Multivariate analyses, including Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA), demonstrated that DLB could be distinctly separated from Alzheimer’s disease (AD) and Parkinson’s disease dementia (PDD) based on metallomic signatures. Specifically, CG, MTG, and PVC profiles enabled discrimination between DLB and AD, while the PVC alone differentiated DLB from PDD. Notably, copper depletion emerged as the only common alteration across DLB, AD, and PDD, underscoring its potential central role in the pathogenesis of neurodegenerative diseases. The authors propose that these metallomic signatures in dementia may reflect disease-specific mechanisms, including variations in oxidative stress, protein aggregation, and mitochondrial dysfunction.

What are the greatest implications of this study?

This study provides compelling evidence that distinct metallomic signatures exist across DLB, AD, and PDD, despite shared pathology such as copper depletion. It strengthens the emerging concept that trace metal dysregulation is disease-specific, rather than a general byproduct of neurodegeneration. The findings support the idea that metallomic signatures profiling—potentially via cerebrospinal fluid or advanced imaging in living patients—could improve differential diagnosis of dementia with overlapping clinical features. Furthermore, the study reinforces the hypothesis that metal dyshomeostasis, particularly copper depletion, may be a contributing pathogenic mechanism, impairing antioxidant defenses and mitochondrial function. These findings could inform new diagnostic tools and therapeutic targets.