[Laboratory examination of contact factors]

The methods of measurement, clinical evaluation and application as molecular marker of contact factors are described. It is important to scrutinize the measurement methods and normal control of contact factors regularly in the institution. A slightly abnormal value and repeated measurement of APTT become valuable, which may reveal asymptomatic hereditary contact factor deficiencies. There is more thrombosis symptoms than bleeding in that cases. Acquired contact factors deficiency is recognized in disseminated intravascular coagulation or liver cirrhosis. Although the cases of the clinical application of molecular marker with contact factors is not enough, the diagnostic and therapeutical trials in hypercoagulopathy with sepsis are starting. There are many unknown clinical functions about contact factors, and careful assessment will be necessary in the previously reported cases of hereditary contact factors deficiency.