Contrasting Etiology of Thrombophilia in Asians and Caucasians

Dai Ohira, Seiichiro Kamimura and Naotaka Hamasaki

Department of Clinical Chemistry and Laboratory Medicine, Chiyukai Shinkomonji Hospital, Japan

^*Correspondance to: Naotaka Hamasaki 

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Abstract:

Background: The primary risk factor for venous thromboembolism in people of Caucasian ethnicity is resistance to the anticoagulant system of activated protein C, caused by the factor V Leiden variant, whereas that in the Japanese population is reduced protein S activity. In Japanese patients, thrombophilia is primary caused by dysfunction of the activated protein C anticoagulant, which mainly results from abnormal protein S molecules with reduced anticoagulant activity. Objective: The purpose of this review is to summarize our research on thrombophilic predisposition in Japanese individuals. We developed a reliable quantitative assay system for precise simultaneous determinations of total protein S activity and total protein S antigen level, using a general-purpose automated analyzer, allowing protein S-specific activity (ratio of total protein S activity to total protein S amount (μg/ml) level) to be calculated. Using the protein S-specific activity method, we systematically screened for the etiology of thrombophilia in Japanese patients suffering from venous, arterial and small vessel thrombosis. Decreased protein S-specific activity was found with high incidences in Japanese patients who suffered venous thromboembolism. Patients/Methods: Our newly developed quantitative analysis of protein S anticoagulant activity could contribute to the early detection of prothrombotic traits in Japanese individuals. Total protein S activity analysis considerably improves the accuracy and reproducibility of measurements, as protein S activity can be measured using a chromogenic substrate without the need for separation of the free and bound forms. The quantitative analysis of protein S anticoagulant activity could facilitate the early detection of prothrombotic traits in Japanese individuals. Conclusions: In Asians populations such as Japanese or Chinese, thrombophilia is primary caused by dysfunction of the activated protein C anticoagulant system, which mainly results from abnormal protein S or protein C molecules with reduced activities of the activated anticoagulant system.

Keywords:

protein C

Cite the Article:

Ohira D, Kamimura S, Hamasaki N. Contrasting Etiology of Thrombophilia in Asians and Caucasians. Ann Clin Case Rep. 2025; 10: 2792..