What is heparin PF4?
Keywords: platelet factor 4, PF4, heparin, PF4/H complexes, HIT. Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening immune complication which occurs after exposure to unfractionated heparin (UFH) or less commonly, to low-molecular weight heparins (LMWHs). 1.
Does heparin normally bind to PF4?
Heparin binding alters native PF4 and elicits immune recognition and response. While the presence of heparin is integral to immunogenesis, the HIT antibody binding site is within PF4. Thus HIT antibodies develop and function to cause thrombocytopenia and/or thrombosis only in the presence of PF4.
What does PF4 stand for?
Platelet factor 4 (PF4) is a small cytokine belonging to the CXC chemokine family that is also known as chemokine (C-X-C motif) ligand 4 (CXCL4) .
What is a PF4 blood test?
A test for heparin-induced thrombocytopenia (HIT) antibody, also called heparin-PF4 antibody, is performed to detect antibodies that develop in some people who have been treated with heparin.
Where is PF4 found?
Although PF4 is found in only trace amounts in human plasma and is stored in platelet α granules, the presence of heparin increases plasma PF4 concentrations 15- to 30-fold by displacing bound PF4 on endothelial cell surfaces.
When should heparin be stopped immediately?
When platelet counts decrease significantly (usually 50 percent of baseline), heparin should be stopped immediately, and, if anticoagulation is necessary, direct thrombin inhibitors like lepirudin or argatroban should be started [2,3].
How is heparin induced thrombocytopenia diagnosed?
Diagnosis of HIT is based on clinical assessment and laboratory results. Primary laboratory tests for HIT include immunologic assays, such as an enzyme-linked immunosorbent assay (ELISA), and functional, platelet-activation assays, such as the serotonin release assay (SRA).
What are the symptoms of heparin induced thrombocytopenia?
What Are the Symptoms of HIT?
- Skin tenderness.
- Swelling.
- Skin that’s warm to the touch.
- Shortness of breath.
- Change in heart rate.
- Sharp pain in your chest.
- Dizziness.
- Anxiety.
What is the name of PF4?
PF4 : Summary
| Code | PF4 |
|---|---|
| One-letter code | X |
| Molecule name | 4,5-bis(4-methoxyphenyl)-2-thiophen-2-yl-1H-imidazole |
| Systematic names | Program Version Name ACDLabs 10.04 4,5-bis(4-methoxyphenyl)-2-thiophen-2-yl-1H-imidazole OpenEye OEToolkits 1.5.0 4,5-bis(4-methoxyphenyl)-2-thiophen-2-yl-1H-imidazole |
| Formula | C21 H18 N2 O2 S |
How do you treat heparin-induced thrombocytopenia?
Thrombocytopenia should be treated with transfusion of washed platelets. Excessive anticoagulation associated with danaparoid can completely be reversed with protamine sulfate. In patients with a history of HIT, heparin can safely be used intraoperatively during cardiac surgery.
Who is at risk for heparin-induced thrombocytopenia?
If thrombocytopenia develops within the first 24 hours of heparin exposure, HIT is considered in patients who have had recent (100 days or less) heparin exposure, because they may have preformed heparin-PF4 antibodies.
What is the treatment for heparin-induced thrombocytopenia?
A direct thrombin inhibitor, such as lepirudin, danaparoid or argatroban, is considered the agent of choice for treatment of HIT.
Can you recover from heparin-induced thrombocytopenia?
Complete platelet-count recovery is seen in ~65% of patients within one week of heparin discontinuation (44). A prolonged duration of thrombocytopenia (>7 days) is usually indicative of severe disease (44).
What medications should not be taken with heparin?
Drug interactions of heparin include medications that increase the risk of bleeding such as aspirin, clopidogrel, warfarin, other anticoagulants, and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, diclofenac, and others, because these add to the effects of heparin and further increase the …