title: Platelet PlA2 Polymorphism and the risk for thrombosis in heparin-induced thrombocytopenia.
abstract: Platelet glycoprotein (GP) IIb/IIIa has an important role in platelet aggregation. A polymorphism of platelet GPIIIa (PlA2, also called HPA1b) has been associated with a higher risk of thrombosis, but its implication in heparin-induced thrombocytopenia (HIT) is unclear. To investigate the hypothesis that the PlA2 polymorphism influences the prothrombotic effects of HIT, we conducted a prospective study of 66 consecutive patients with a laboratory diagnosis of HIT. The end point of the study was the diagnosis of a thrombus within 30 days of the positive HIT test result. The Diagnostica Stago (Asnières, France) enzyme-linked immunosorbent assay was used to detect HIT antibodies, and a polymerase chain reaction assay was used to detect the PlA2 polymorphism. Of the 66 patients, thrombotic complications developed in 27 (41%). Patients with the PlA2 allele demonstrated a significantly higher thrombosis risk than did patients without (69% vs 32%; P = .0088; odds ratio, 4.68; 95% confidence interval, 1.39-15.72). The risk was stronger for arterial thrombosis and for patients 60 years or older. There was a significant association between the PlA2 polymorphism of GPIIIa and the risk of thrombosis in patients with HIT antibodies.
authors.affiliation: Coagulation Laboratory, Department of Pathology, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Harris
authors.forename: Phan
authors.initials: P
authors.lastname: Nguyen
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Van Cott
mesh_terms: D000367:Age Factors; D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D039661:Integrin beta3 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D012306:Risk; D013921:Thrombocytopenia / Q000139:chemically induced / Q000235:genetics* / Q000401:mortality; D013927:Thrombosis / Q000209:etiology* / Q000401:mortality
chemical_list: D039661:Integrin beta3; D006493:Heparin