Hereditary partial deficiency of plasminogen activator inhibitor-1 associated with a lifelong bleeding tendency.

We report a family with a partial deficiency of plasminogen activator inhibitor-1 (PAI-1). The affected family members had had lifelong bleeding episodes, such as rebleeding after tooth extraction and trauma. This bleeding tendency in the propositus was autosomally transmitted from grandfather to son. The characteristic abnormalities of fibrinolysis in the patients were shortened eugloblin lysis time, low PAI activity with low antigen levels of plasminogen activator inhibitor-1 in plasma and serum. Furthermore, plasma 'active PAI' which indicates the quantity of plasminogen activator inhibitor-1 bound with plasminogen activator added was very low in these patients. These parameters were markedly low after the venous occlusion test. Moreover, two of the affected members had a much lower level of platelet PAI-1 than the normal controls. Tranexamic acid (Transamine) was useful to control bleeding in these patients.