Nitrite

metabolite

Elevated nitrite indicates reactive oxygen species-driven oxidation of nitric oxide and impaired endothelial-protective NO signaling.

Pathway placement

Cascade stepEndothelial activation & erosion

Confidencemedium

RationaleNitrite reflects depleted NO bioavailability; marker of endothelial oxidative stress.

Druggability

Not assessed (no mapped human gene target).

Type I vs Type II discrimination

ScoresType-II-associated

R — rupture / Type-I

—

C — confounder / Type-II

A — assay feasibility

E — evidence strength

T1DI (composite)

Specificity differential (R−C)-40.6

Confounder panel (Type-II drivers)

1sepsis / systemic inflammationmag 2

2anemia / acute blood lossmag 0

3hypovolemia / dehydrationn/a

4tachyarrhythmiamag 2

5hypoxemia / respiratory failuremag 2

6hypertensive emergencymag 2

7high-demand / peri-operative stressmag 2

Coverage: 6/7 confounders with evidence

Tier: deep-scored (abstract-extracted) · 14 supporting references. See the discrimination table for all markers.

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