[Urgent hemostatic control with Confact F for ovarian bleeding complicated by an unknown type of von Willebrand disease].

Emergency surgery was performed on a 24-year-old female patient with an unknown type of von Willebrand disease (VWD). The patient suddenly developed lower abdominal pain and was transported to our hospital by ambulance. Based on the diagnosis of ovarian bleeding, emergency surgery was indicated. Ristocetin-cofactor activity (VWF: RCo) was between 7% and 14% by measurement with von Willebrand reagent (Dade Behring, Marburg, Germany). A laparoscopic partial resection of the left ovary was performed under administration of factor VIII/VWF concentrate, Confact F((R)) (Chemo-Sero-Therapeutic Research Institute, Kumamoto, Japan). During and after surgery, there was no abnormal bleeding. The results obtained by measurement by the reagent were similar to the levels of VWF: RCo obtained by the fixed platelet agglutination method. The reagent was useful for diagnosing and monitoring the VWF: RCo level to control bleeding in VWD.

[Prothrombin time and its standardization].

This review regarding prothrombin time and its standardization is described around some recent topics as the followings. 1. History of standardization for prothrombin time and revised WHO guideline for thromboplastin; A short history of standardization is summarized to understand a scheme of International Normalized Ratio (INR) based on International Sensitivity Index (ISI) that is calibrated by International Reference Preparation (IRP) for thromboplastin, and some key points in revised WHO guideline for thromboplastin and plasma used to control oral anticoagulant therapy are interpreted for research and practical use. 2. Point-of-care prothrombin time monitoring; A portable device to measure prothrombin time with whole blood sample, such as CoagChek (Roche), contributes to self-management by patients required long-term oral anticoagulation. Some investigators reported clinical agreement to use this monitoring system and improvement of patient's QOL and cost-effectiveness in overseas. 3. New types of thromboplastins; Two new types of thromboplastins have been available since the last year in Japan. One is a human plain thromboplastin, Simplastin HTF (Bioméreux) from extract of cultured human lung cancer cell, and another is IL test PT-Fibrinogen Recombinant (Iatron) from recombinant rabbit tissue factor relipidated in a synthetic phospholipid blend. For control of oral anticoagulation, good performance are expected in either thromboplastins because of their sufficient low ISI values. 4. INR methodology for other diseases; INR/ISI system is designed as a standardized methodology for control of oral anticoagulation. Prothrombin time, however is utilized as a global coagulation test for diagnosis or criteria of other disorders, such as congenital coagulation factor deficient, severe liver dysfunction and disseminated intravascular coagulation. Previous our study indicated that discrepancy of sensitivities to plasma absorbed multiple coagulation factors and plasma from patients under oral anticoagulation was revealed in rabbit brain thromboplastins, but not in human origins. Discrepancy of sensitivities observed in rabbit thromboplastins was emphasized in convert to INR values. These results suggested that the use of human thromboplastin of which ISI is close to 1.0 leads possibility for introducing INR methodology to evaluate PT of other disorders.

[Introduction of international normalized ratio of prothrombin time to evaluate multiple depletions of coagulation factors].

Prothrombin time(PT) is utilized in worldwide as a global coagulation test reflected multiple depletions of coagulation factors in diseases such as severe liver dysfunction and Disseminated Intravascular Coagulation(DIC). However, standardization of regents and result reporting methods are not established yet except International Normalized Ration(INR) for control of oral anticoagulant therapy(OAT). We evaluated whether INR is capable for defect of multiple coagulation factors except OAT, using absorbed plasma and different origins of thromboplastin; human recombinant, human placenta, cultured human cell and rabbit brain. PTs of individual 90 samples(group MC) absorbed with BaSO4 and/or bentnite and 60 samples(group W) from patients with OAT were measured with 20 normal plasmas with respective reagents. Sensitivities of four reagents to plasma of group W and MC were determined respectively against human recombinant thromboplastin(ISI = 1.03). Both of human thromboplastin showed that sensitivity to absorbed plasma was very close to OAT plasma, whereas reductions of sensitivity to 84% and 66% for absorbed plasma were revealed in both of rabbit thromboplastins. Correlations of INRs calculated by two different sensitivities, one is to absorbed plasma and another to OAT plasma, indicated that discrepancy of sensitivities was emphasized as large slopes(1.50 and 2.76) of regression lines and large intercepts in rabbit thromboplastins, although slopes closed to 1.0 with small intercepts in both of human thromboplastins. We concluded that use of human thromboplastin was the first priority to introduce INR system for evaluation of multiple coagulation factors depletions.

[Prothrombin time and its standardization: a potentiality to introduce INR method in criteria for disseminated intravascular coagulation].

Prothrombin time (PT) is widely utilized for evaluation of diseases with single or multiple coagulation factors disorders, such as severe liver dysfunction and disseminated intravascular coagulation (DIC). However, its standardization of reagent and method is not established yet for universal purpose except International Normalized Ratio (INR) for control of oral anticoagulant therapy (OAT). Neither Prothrombin time ratio adapted in Japanese criteria for DIC nor seconds method in criteria reported by the last SSC meeting is corrected between assays, therefore much dependence on these criteria causes risk of misdiagnosis. In order to resolve incoherence of method of PT, we performed this study for introducing INR method to diagnostic criteria for DIC. In our results, sensitivities of two reagents from human tissue factor (TF) to DIC model plasma with middle to low activities of multiple coagulation factors almost equal to plasma from patients with OAC, although other two reagents from rabbit TF show discrepancy of sensitivities between DIC and OAT plasma. These suggest a potentiality to introduce INR system to diagnosis of DIC when human TF is used as a PT reagent. Based on standardization of method, significance of PT in DIC criteria should be reevaluated in worldwide.