Diagnostica Stago

Societe Diagnostica-Stago

Patrick Van Dreden

Jean-Luc Martinoli

Barry Woodhams

Aurelie Rousseau

Aurélie Rousseau

The invention concerns the field of hemostasis, in particular blood coagulation disorders linked to an abnormal expression of tissue factor, and to physiopathological phenomena correlated with over-expression of the factor. The present invention provides a method for assaying the activity of circulating tissue factor in a biological sample. The method of the invention is carried out in vitro, in particular on a blood sample collected from a patient.

Method for in vitro assay of the circulating tissue factor, and use in the detection of coagulation diseases

A process for determining a resistance to activated protein C of a test specimen of human plasma following the steps of: (1) mixing together (a) the test specimen of human plasma, (b) a reactant deficient in factor V which supplies at least most of the coagulation factors other than factor V, and (c) the venom of,which specifically activates factor X to Xa, and incubating the mixture of (a), (b) and (c) for at least one minute at a temperature of between 10 and 45&deg; C.; (2) introducing into the incubated mixture(i) Ca,or (ii) Ca,&plus;exogenic activated protein C; and (3) determining the coagulation time (i) in the absence of activated protein C and (ii) in the presence of activated protein C. Steps (1) to (3) are repeated, but replacing, in step (1), the test specimen with a normal plasma as control and correlating resistance to activated protein C by comparing the determinations made in steps for the test specimen and for the normal plasma. The initiation of coagulation is caused by activating factor X to Xa using the venom of,in the presence of (i) Ca,or (ii) Ca,&plus; exogenic activated protein C.

Process for determining a resistance to activated protein C

The invention relates to the use of a serum rich in factor Va for the preparation of compositions useful as pathological controls or calibrants in methods for analyzing resistance to activated protein C (APC), as well as said compositions, the method for their preparation and a method for the detection of resistance to activated protein C.

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Maisons-Alfort, France

Patrick Van Dreden