Heparin-induced thrombocytopenia (HIT) is a severe complication of heparin therapy, characterized by thrombocytopenia and an increased risk for thrombotic complications secondary to the formation of IgG antibodies (Ab), recognizing a complex of heparin (H) and PF4. Using the 4T clinical score for HIT and the presence of heparin-associated Ab assayed by enzyme-linked immunosorbent assay and heparin-induced platelet aggregation, we define the phenotype of three groups of patients: 51 H/PF4/Ab patients with antibodies and without thrombocytopenia; 50 patients with thrombocytopenia (HIT) and 53 patients with thrombosis (HITT). In these patients we studied four polymorphisms: FcγRIIA-H131R, GpIIb/IIIa-HP-1, PECAM1-L125V (in linkage-disequilibrium with S563N and R670G), and FcγRIIIA-F158V, to understand if these variations may influence the different phenotypes of the patients. There were no difference in genotype or allele frequencies between controls and the three groups of patients. Afterward, we created a genotype score for multiple risk alleles for thrombosis considering as risk genotype FcγRIIA R/R131, HPA-1a/b, and PECAM1-V/V125. These polymorphisms were overrepresented in HITT patients, ascertained by a permutation test (10 000 replicates) p = 0.0198 for the two-single-nucleotide polymorphism (SNP) model and p = 0.0119 for the three-SNP model. The calculated odds ratio for thrombosis was 4.01[CI: 2.30-6.96] in the case of the presence of two at risk genotypes and 8.002 [CI: 4.59-13.93] if all the three at risk genotypes were present. In conclusion these polymorphisms could contribute to the risk of thrombotic complications in HIT.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.3109/09537104.2012.701026 | DOI Listing |
Pharmaceuticals (Basel)
November 2024
Independent Researcher, 5345 MT Oss, The Netherlands.
(1) Background: Danaparoid sodium is a heparinoid antithrombotic that has been used for over 40 years for prophylaxis of DVT in non-HIT patients and for the treatment of heparin-induced thrombocytopenia (HIT) with and without thrombosis. This update summarises current information on its pharmacology and reviews danaparoid dose management in a broad spectrum of clinical situations, including off-label indications. (2) Methods: Evidence from published clinical studies, case reports, compassionate use of danaparoid, and spontaneously reported serious adverse events is summarised and analysed by an interdisciplinary expert group to develop a consensus on dosing regimens of danaparoid for complex clinical situations, including vulnerable patient populations.
View Article and Find Full Text PDFJ Appl Lab Med
January 2025
Department of Pathology, University of Iowa Health Care, Iowa City, IA, United States.
Background: Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening adverse drug reaction with numerous diagnostic challenges. Diagnosis of HIT begins with 4T score clinical assessment, followed by laboratory testing for those not deemed low risk. Laboratory testing for HIT includes screening [enzyme-linked immunosorbent assay (ELISA)] and confirmatory [serotonin release assay (SRA)] assays, wherein SRA testing can be pursued following a positive ELISA result.
View Article and Find Full Text PDFHeparin-induced thrombocytopenia (HIT) is an adverse drug reaction with significant thromboembolic risk. Though there are models for use of non-heparin anticoagulants, heparin remains the preferred anticoagulant in many operative settings, especially cardiovascular surgery and percutaneous cardiac intervention. The natural history of HIT can be stereotyped into phases using HIT laboratory testing to guide clinical management and determine whether heparin re-exposure can be considered.
View Article and Find Full Text PDFJ Thromb Haemost
December 2024
Division of Hematology, Duke University Medical Center, Durham, North Carolina, USA. Electronic address:
Background: Immunoglobulin G antibodies (Abs) to platelet factor 4 (PF4) complexed to heparin (PF4/H) commonly occur after H exposure but cause life-threatening complications of H-induced thrombocytopenia (HIT) in only a few patients. Presently, only platelet activation assays reliably distinguish anti-PF4/H Abs that cause disease (HIT Abs) from those likely to be asymptomatic (AAbs).
Objectives: Recent studies indicate that complement activation is an important serologic property of HIT Abs and is essential for IgG Fc receptor IIA-mediated cellular activation.
J Tehran Heart Cent
January 2024
Department of Cardiac Electrophysiology, Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Background: The rate of lead extraction has steadily increased alongside the extensive use of cardiovascular implantable electronic devices. Data on the complications and safety of this challenging procedure are limited. We investigated inhospital and midterm outcomes following lead extraction.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!