Antithrombin III, Heparin Cofactor and Antifactor Xa in Relation to Age, sex And Pathological Conditions

Determinations of AT-III activity, heparin cofactor activity, antifactor Xa activity and AT-III protein were carried out in 200 healthy adults, evenly distributed within age and sex groups, in 60 patients with cerebral thrombosis and in 20 oral contraceptive users. There was a positive correlation between AT-III protein and its activitiesin normal subjects and in patients with cerebral thrombosis. In oral contraceptive users the positive correlation was between AT-III protein and its activities, antifactor Xa activity excepted. The mean AT-III protein and heparin cofactor activity values decreased in males with age and were significantly lower in the groups between 50 and 70 years. The mean AT-III protein and heparin cofactor activity values decreased slightly in women in fertile age and were lower in the 40 to 50 age-group. The mean AT-III protein and its activities values did not show any variation in the patients with cerebral thrombosis. The mean antifactor Xa activity value in the women, taking the pill for 3 months, decreased, whereas the other AT-III activities and AT-III protein were unchanged.