THE CLINICAL-VALUE OF TISSUE FACTOR ASSAYS

Tissue factor (TF) is now considered to be the primary physiologic act ivator of the blood coagulation system. Coupled with recent advances i n our understanding of the biochemistry of TF this has heightened inte rest in measuring aspects of TF activity in disease states. Expression of TF by blood monocytes in various diseases is an established trigge r for intravascular coagulation and there is now a considerable body o f experience with its measurement. This has considerable clinical pote ntial although more widespread application awaits a consensus on the m ost appropriate methodologic approach to its measurement. TF can be de tected in urine and may reflect the activation state of renal macropha ges. Urinary TF is increased in cancer and could have diagnostic and p rognostic value in a variety of malignant diseases. Finally, it is now possible to measure soluble TF in plasma. One such assay is commercia lly available and is technically simple to perform. The clinical value of such assays, however, must await better understanding of the sourc e and function of soluble TF in plasma.