ABSTRACT
The determination of plasma factor Ⅷ related antigen (ⅧR:Ag) is a new method to estimate the function of blood coagulation introduced only recently. The concentration of this substance of 50 patients ill with chronic renal failure, neoplastic diseases, diabetes mellitus, (all these diseases were complicated with vascular changes) and 60 normal persons were determined.The data obtained showed that the concentration of plasma factor Ⅷ related antigen was significantly increased in all the 50 patients in comparing with the normal, and the increase was most marked in those patients with malignant diseases. The clinical significance of this phenomenon was discussed and it was suggested that the increase of this plasma factor Ⅷ related antigen might reflect the severity of the damage of the vascular endothelial cells in these patients.