We have analyzed a female patient who expressed recurrent spontaneous bleeding in her age 40s with an obvious APTT prolongation. However, her diagnosis had difficulties due to her complicated laboratory results. Her laboratory tests showed a significant reduction of all intrinsic coagulation factors (factors VIII, IX, XI, and XII), and the presence of high titer antibodies to factor XI was presumed by the results of the crossing mixing test, the coagulation factor assays with multi-diluted samples, the immunological methods and the synthetic chromogenic substrate methods. The immunological analysis which use IgG purified from patient plasma was confused due to the strong affinity of IgG and factor XI. However, it was revealed that the antibody was directed against factor XI by combination use of chromogenic substrate assay for factor VIII and factor IX. There are only a limited number of reports of such cases, and the results of coagulation factor level often become false values which are interfered by high titer inhibitor. It is very important to properly grasp the disease state from multiple distinct analyses.

Retinal Vein Occlusion is caused by thrombus formation. Retinal arteries and arterioles and their corresponding veins share a common adventitial sheath. It is considered that the thickening of the arteriole compresses the vein, eventually causing thrombus formation. Current treatment methods are not direct removal of thrombus, only symptomatic treatment. For the present study, the micro-vascular of the chicken embryo was employed as a retina vein occlusion phantom as a simple model of alive blood vessel. Artificial blood clot was produced by the mixture of the fibrinogen, thrombin and blood of the venous thrombus component. This study will contribute to produce a library of a wide range of properties of blood clot to evaluate the developed mechanical medical devices.