title: [Effect of heparin cofactor II on the antithrombin III activities measured by thrombin methods or factor Xa methods--fundamental studies and clinical studies using the plasma of pregnant women].
abstract: We evaluated the effects of heparin cofactor II(HC II) on the antithrombin III(AT III) activities measured by the methods of thrombin or factor Xa. Reagents A and B were using the method of thrombin and reagent C was based on the method of Xa. Purified HC II was directly measured or indirectly measured after the dilution with control plasma. Cross reaction of HC II in AT III assay were negligible in reagent C, but substantial amount of AT III activities were measured in reagent A and B. Plasma AT III activities from full-term pregnant women were significantly higher than those from non pregnant control women in reagent A, but comparable in reagent B or C. These results indicate that AT III activities measured by thrombin methods by thrombin were overestimated in pregnant women due to the cross-reactivities of HC II. It is recommended that AT III activities would be measured by the methods of factor Xa.
authors.affiliation: Clinical Laboratories, Kyoto University Hospital.
authors.forename: Y
authors.initials: Y
authors.lastname: Akai
authors.forename: S
authors.initials: S
authors.lastname: Shiga
authors.forename: K
authors.initials: K
authors.lastname: Tohyama
authors.forename: A
authors.initials: A
authors.lastname: Shimatsu
authors.forename: S
authors.initials: S
authors.lastname: Ichiyama
mesh_terms: D000990:Antithrombin III / Q000378:metabolism*; D001780:Blood Coagulation Tests / Q000379:methods*; D015951:Factor Xa; D005260:Female; D015844:Heparin Cofactor II / Q000494:pharmacology*; D006801:Humans; D007202:Indicators and Reagents; D011247:Pregnancy; D013917:Thrombin
chemical_list: D007202:Indicators and Reagents; D015844:Heparin Cofactor II; D000990:Antithrombin III; D013917:Thrombin; D015951:Factor Xa