Altered Cerebrospinal Fluid Tryptophan-Kynurenine Pathway Metabolism in Multiple System Atrophy

Area of Science:

• Neuroscience
• Metabolic pathways
• Neurodegenerative diseases

Background:

• Tryptophan-kynurenine (TRP-KYN) metabolism alterations are linked to neuroinflammation but are poorly understood in multiple system atrophy (MSA).
• Investigating TRP-KYN pathway in MSA is crucial for understanding disease mechanisms.

Purpose of the Study:

• To investigate cerebrospinal fluid (CSF) TRP metabolites in MSA patients compared to controls.
• To explore associations between TRP metabolites and other CSF biomarkers in MSA.

Main Methods:

• Analyzed CSF samples from 51 MSA patients and 56 controls.
• Measured TRP metabolites (KYN, QA, KA) and biomarkers (NfL, GPNMB, sTREM2) using specific assays.

Main Results:

• MSA patients had higher quinolinic acid (QA) and lower kynurenic acid (KA), resulting in an elevated QA-to-KA ratio.
• QA and KA levels did not correlate with clinical scores in MSA.
• Increased NfL, GPNMB, and sTREM2 were observed in MSA but were independent of KYN pathway metabolites.

Conclusions:

• Multiple system atrophy demonstrates a significant imbalance in KYN metabolism, indicating a shift towards inflammatory processes.
• This metabolic shift in MSA appears distinct from established neuroinflammatory markers.
• Findings suggest novel therapeutic targets within the TRP-KYN pathway for MSA.