title: Predictors for the development of elevated anti-heparin/platelet factor 4 antibody titers in patients undergoing cardiac catheterization.
abstract: A substantial proportion of patients who undergo cardiac catheterization develop antibodies directed against the heparin/platelet factor 4 (PF4) complex after the procedure, which have been implicated in the pathogenesis of heparin-induced thrombocytopenia. This study attempted to identify factors that predicted the development of these antibodies in a prospective cohort study. Antiheparin/PF4 antibody titers were measured at baseline and again 5 +/- 2 days after cardiac catheterization by enzyme-linked immunosorbent assay. A total of 311 patients who underwent cardiac catheterization were included in the analysis. Of these, 25 (8.0%) developed positive antibody levels after catheterization. Patients who had positive antibody test results after catheterization had significantly greater baseline antiheparin/PF4 antibody titers compared with those whose titers remained low (optical density 0.227 vs 0.158, p < 0.001). In a logistic regression model, greater baseline antibody titers, a history of heparin exposure, and a lower platelet count at enrollment were the strongest predictors of conversion to positive antiheparin/PF4 antibody titers after cardiac catheterization. It is possible to identify patients at high risk for developing elevated titers of antiheparin/PF4 antibodies on the basis of their baseline clinical characteristics.
authors.affiliation: Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Yeh
authors.forename: Brendan M
authors.initials: BM
authors.lastname: Everett
authors.forename: Shi-Yin
authors.initials: SY
authors.lastname: Foo
authors.forename: David J
authors.initials: DJ
authors.lastname: Dorer
authors.forename: Michael
authors.initials: M
authors.lastname: Laposata
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Van Cott
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
mesh_terms: D000906:Antibodies / Q000276:immunology*; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4 / Q000276:immunology*; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced / Q000276:immunology*
chemical_list: D000906:Antibodies; D000925:Anticoagulants; D010978:Platelet Factor 4; D006493:Heparin