L-cysteine
metaboliteL-cysteine serves as a systemic biomarker of metabolic/nutritional status influencing cardiovascular risk in acute MI.
Pathway placement
Cascade stepOff-pathway / systemic markers
Confidencemedium
RationaleAmino acid risk marker; systemic metabolic/nutritional axis independent of atherothrombotic cascade.
Druggability
Not assessed (no mapped human gene target).
Type I vs Type II discrimination
ScoresLow-confidence (proxy)
R — rupture / Type-I48
C — confounder / Type-II84
A — assay feasibility42
E — evidence strength31
T1DI (composite)4
Specificity differential (R−C)-36.1
Confounder panel (Type-II drivers)
No confounder evidence retrieved.
Tier: light (literature co-occurrence proxy — lower confidence). See the discrimination table for all markers.
Assay & specimen
Class-level default (no specific cleared assay)— generic method inferred from analyte class; confirm against a specific product insert before use.
Specimen
Serum, plasma or urine
Collection tube
Serum separator (gold/red-top, SST) · Lithium heparin (green-top) · Sterile urine container
Method / principle
LC-MS/MS (targeted metabolomics) or enzymatic colorimetric where available
Reagent / substrate
Stable-isotope-labeled internal standard (MS); or enzyme-coupled Trinder reagent
Platform
LC-MS/MS; some automated chemistry
Turnaround · availability
Send-out / research · Specialized / research
Literature evidence(1)
- High-resolution metabolomics study revealing l-homocysteine sulfinic acid, cysteic acid, and carnitine as novel biomarkers for high acute myocardial infarction risk.Metabolism: clinical and experimental · 2019 · PMID 31874143 · doi