C4d

protein

C4d deposition marks platelet activation and complement engagement in arterial thrombosis.

Pathway placement

Cascade stepPlatelet adhesion & activation

Confidencemedium

RationaleComplement-activation fragment deposited on platelet surface during activation and thrombosis.

Also acts inVascular inflammation

Druggability

Not assessed (no mapped human gene target).

Type I vs Type II discrimination

ScoresLow-confidence (proxy)

R — rupture / Type-I

C — confounder / Type-II

A — assay feasibility

E — evidence strength

T1DI (composite)

Specificity differential (R−C)-4.9

Confounder panel (Type-II drivers)

No confounder evidence retrieved.

Tier: light (literature co-occurrence proxy — lower confidence). 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 or plasma

Collection tube

Serum separator (gold/red-top, SST) · K2/K3-EDTA (lavender-top)

Method / principle

Sandwich immunoassay (ELISA) — research-grade unless a cleared assay exists

Reagent / substrate

Matched anti-target antibody pair (capture + labeled detection)

Platform

ELISA microplate or multiplex (Luminex/MSD)

Turnaround · availability

Send-out / research · Research-grade (no universal clinical assay)