METHOD OF MEASURING LUPUS ANTICOAGULANT SUBSTANCE ANTIBODY AND MEASURING REAGENT

PURPOSE: To measure an lupus anticoagulant substance(LA) antibody causing thrombus specifically and quantitatively by adding a predetermined quantity of activated protein C into a blood-, a plasma-, and a tissue sample and, after holding them thermostatically, measuring the residual quantity of physiological substrate of the protein C in the sample or the activity of protein S. CONSTITUTION: In order to measure the LA-antibody in a blood-, a plasma-, and a tissue sample by suppressing the neutralization of activated protein C on a coagulation system with an LA-antibody, a predetermined quantity of activated protein C is added to the sample and, after holding the sample thermostatically, the residual quantity of physiological substrate of the protein C in the sample or the activity of protein S is measured. The quantity of existing LA-antibody is the compared with a standard containing no LA-antibody. The suppression rate of the activity of activated protein C in a group of patient where the LA-antibody is detected has no correlation with the measure concentration of LA-antibody but has a good correlation with the sporadic emergency of thrombus.