Platelet Factor 4
PF4proteinPF4 is released upon platelet activation and serves as an early biomarker of platelet recruitment and thrombus formation in Type 1 MI.
Pathway placement
Cascade stepPlatelet adhesion & activation
Confidencehigh
RationaleAlpha-granule release marker; platelet activation in AMI and STEMI; s5 anchor.
Druggability
DruggableYes
Known drugs / candidates0
Small-molecule tractableYes
Antibody tractableYes
EnsemblENSG00000163737
Type I vs Type II discrimination
ScoresType-II-associated
R — rupture / Type-I0
C — confounder / Type-II67
A — assay feasibility68
E — evidence strength42
T1DI (composite)5
Specificity differential (R−C)-66.7
Confounder panel (Type-II drivers)
1sepsis / systemic inflammationmag 2
2anemia / acute blood lossmag 2
3hypovolemia / dehydrationn/a
4tachyarrhythmian/a
5hypoxemia / respiratory failuremag 2
6hypertensive emergencyn/a
7high-demand / peri-operative stressmag 2
Coverage: 4/7 confounders with evidence
Tier: deep-scored (abstract-extracted) · 15 supporting references. 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 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)
Literature evidence(32)
- Multidomain Biomarkers as Predictors of Cardiovascular Risk in Acute Coronary Syndrome: A Prospective Evaluation.International journal of molecular sciences · 2026 · PMID 41828690 · doi
- Biomarkers of in vivo platelet activation in coronary artery disease: a systematic review and meta-analysis: communication from the SSC of the ISTH.Journal of thrombosis and haemostasis : JTH · 2025 · PMID 40685139 · doi
- Single-cell transcriptomic analysis of peripheral blood mononuclear cells reveals key immune responses in ST-segment elevation myocardial infarction.Hereditas · 2025 · PMID 41291938 · doi
- Platelets as an inter-player between hyperlipidaemia and atherosclerosis.Journal of internal medicine · 2024 · PMID 38704820 · doi
- Molecular Biomarkers for In Vitro Thrombogenicity Assessment of Medical Device Materials.Journal of biomedical materials research. Part B, Applied biomaterials · 2024 · PMID 39340365 · doi
- Decreased Platelet Reactivity and Function in a Mouse Model of Human Pancreatic Cancer.Thrombosis and haemostasis · 2023 · PMID 36716775 · doi
- Platelet activation and endothelial dysfunction biomarkers in acute coronary syndrome: the impact of PCSK9 inhibition.European heart journal. Cardiovascular pharmacotherapy · 2023 · PMID 37468450 · doi
- Angiogenic content of microparticles in patients with diabetes and coronary artery disease predicts networks of endothelial dysfunction.Cardiovascular diabetology · 2022 · PMID 35109843 · doi
- Serum proteomic analysis reveals the cardioprotective effects of Shexiang Baoxin Pill and Suxiao Jiuxin Pill in a rat model of acute myocardial infarction.Journal of ethnopharmacology · 2022 · PMID 35405256 · doi
- Study on Proteomics-Based Aortic Dissection Molecular Markers Using iTRAQ Combined With Label Free Techniques.Frontiers in physiology · 2022 · PMID 35910577 · doi
- Searching for Novel Candidate Biomarkers of RLS in Blood by Proteomic Analysis.Nature and science of sleep · 2021 · PMID 34234594 · doi
- The human platelet transcriptome and proteome is altered and pro-thrombotic functional responses are increased during prolonged hypoxia exposure at high altitude.Platelets · 2019 · PMID 30721642 · doi
- Discovery of potential plasma protein biomarkers for acute myocardial infarction via proteomics.Journal of thoracic disease · 2019 · PMID 31656670 · doi
- rLj-RGD3, a novel recombinant toxin protein from Lampetra japonica, prevents coronary thrombosis-induced acute myocardial infarction by inhibiting platelet functions in rats.Biochemical and biophysical research communications · 2018 · PMID 29407168 · doi
- Associations between ambient wood smoke and other particulate pollutants and biomarkers of systemic inflammation, coagulation and thrombosis in cardiac patients.Environmental research · 2017 · PMID 28167447 · doi
- Platelet activation at the onset of human endotoxemia is undetectable in vivo.Platelets · 2016 · PMID 26764560 · doi
- Altered plasma fibrin clot properties in essential thrombocythemia.Platelets · 2015 · PMID 25989112 · doi
- Platelet depletion, platelet activation and coagulation during treatment with hemodialysis.Scandinavian journal of clinical and laboratory investigation · 2011 · PMID 21303224 · doi
- Plasma markers of platelet and polymorphonuclear leukocyte activation in young adults with acute myocardial infarction.Clinical hemorheology and microcirculation · 2005 · PMID 15665428
- Relationship between release of platelet/endothelial biomarkers and plasma levels of sertraline and N-desmethylsertraline in acute coronary syndrome patients receiving SSRI treatment for depression.The American journal of psychiatry · 2005 · PMID 15932816 · doi
- Comparison of the effects of cellulose triacetate and polysulfone membrane on GPIIb/IIIa and platelet activation.Blood purification · 2003 · PMID 12601261 · doi
- Enhanced platelet/endothelial activation in depressed patients with acute coronary syndromes: evidence from recent clinical trials.Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis · 2003 · PMID 12960610 · doi
- Cardiopulmonary bypass induces release of soluble CD40 ligand.Circulation · 2002 · PMID 12070112 · doi
- A reliable plasma marker of platelet activation: does it exist?American journal of hematology · 2002 · PMID 12111787 · doi
- Thrombogenesis in sickle cell disease.The Journal of laboratory and clinical medicine · 2001 · PMID 11385360 · doi
- Heparin-induced thrombocytopenia/thrombosis in a transgenic mouse model requires human platelet factor 4 and platelet activation through FcgammaRIIA.Blood · 2001 · PMID 11588041 · doi
- GPV is a marker of in vivo platelet activation--study in a rat thrombosis model.Thrombosis and haemostasis · 2000 · PMID 10739394
- Plasma and platelet plasminogen activator inhibitor-1 in patients with acute myocardial infarction.Japanese circulation journal · 2000 · PMID 10952148 · doi
- Useful laboratory tests for studying thrombogenesis in acute cardiac syndromes.Clinical chemistry · 1998 · PMID 9702994
- Increased heparin-releasable platelet factor 4 and D dimer in patients one month after the onset of acute myocardial infarction: persistent activation of platelets and the coagulation/fibrinolytic system.International journal of cardiology · 1994 · PMID 7737755 · doi
- [Biological manifestations of a prethrombotic state in developmental Crohn's disease].Gastroenterologie clinique et biologique · 1990 · PMID 2188861
- Fibrinopeptide A, platelet factor 4, and beta-thromboglobulin levels in coronary heart disease.Blood · 1982 · PMID 6179552