JAK2V617F mutation in patients with thrombosis: to screen or not to screen?
Quebec platelet disorder (QPD) is an autosomal dominant bleeding disorder associated with increased risks for bleeding and the expression and storage of urokinase plasminogen activator (u-PA) in platelets, despite normal u-PA in plasma (reviewed in ). In the recent article on QPD published in this journal , QPD was proposed to result from defective u-PA regulation by megakaryocytes. However, the levels of u-PA in other QPD cells and urine have not been reported. Individuals with QPD are at increased risk of experiencing bleeding following hemostatic challenges, and approximately 50% experience episodic, spontaneous hematuria, which is associated with higher levels of platelet u-PA . As urine normally contains significant amounts of u-PA (40–80mg/ml) , we investigated whether individuals with QPD have an increased urinary u-PA as a potential contributor to their urinary tract bleeding.