RESUMEN
OBJECTIVE@#To investigate the pathogenesis of unknown nosebleed patients.@*METHOD@#The ELISA test were used to detected plasma Urokinase-type plasminogen activator (uPA) and Urokinase-type plasminogen activator receptor (uPAR) level in 19 cases unknown factor nosebleed patients and 36 health persons.@*RESULT@#The results showed uPAR and uPA level in nosebleed group (before treatment) uPAR (0.14 +/- 0.04) microg/L, uPA (0.24 +/- 0.09) microg/L; (after treatment) uPAR (0.08 +/- 0.02) microg/L, uPA (0.18 +/- 0.07) microg/L. And normal group uPAR (0.07 +/- 0.03) microg/L, uPA (0.17 +/- 0.05) microg/L. The uPAR and uPA level in nosebleed group before treatment is higher than that in normal group (P 0.05).@*CONCLUSION@#The reasons of uPAR and uPA level high in unknown factor nosebleed patients were not clear, maybe relation to vascular endothelial cell, smooth muscle cell and neutrophil-monocytic release more uPAR and uPA. So uPAR and uPA density of nostril accumulation is more high in its microenvironment, that fibrinolytic system activated increase and result in its hyperactivity, and happened nosebleed when blood be in hypocoagulable state.