Author: Fang Qian, Zhang Lixia
Unit: Hebei Provincial Children's Hospital
Outpatient clinics often see some children with ecchymosis on the skin, nasal bleeding is not easy to stop, but the results of the examination of platelets are normal, the four blood clotting items are normal or the APTT is slightly prolonged, and it is not known that this may be vascular hemophilia.
Von Willebrand diseas (VWD) is an autosomal (dominant or recessive) inherited bleeding disorder caused by a deficiency in the amount of vOil Willebrand factor (vWF) and/or qualitative abnormalities.
vWF is a plasma protein that mediates platelet adhesion at the site of vascular injury, plays a key role in platelet adhesion and aggregation, and binds to and stabilizes coagulation factor VIII (FVIII) in blood circulation. vWF deficiency can affect platelet adhesion, aggregation, and reduce the level of FVIII in the blood circulation, resulting in clinical bleeding manifestations.
VWD is the most common hereditary bleeding disorder (incidence 0.5% to 1.5%), but only 1% of patients have hemorrhagic manifestations, although the incidence is quite high, but there are not many patients with bleeding manifestations. It can occur in both men and women, some have a family history, and the onset occurs since childhood, most of which are spontaneous bleeding.
The reason why it is called vascular hemophilia is because its bleeding manifestations are both vascular bleeding, that is, bleeding from the skin mucosa, such as skin ecchymosis, epistaxis, bleeding gums, menorrhagia, gastrointestinal bleeding, etc., and there are bleeding manifestations similar to hemophilia, such as bleeding after dental treatment, bleeding after trauma and surgery, muscle and joint bleeding, etc. The severity of bleeding varies from patient to patient, and bleeding manifestations in the same patient may also change over time.
Clinically encounter patients with bleeding, we do a coagulation function test. If the platelets are normal in the blood routine, the four PT coagulations are normal, the APTT is normal or prolonged, the plasma FVIII activity is normal, and the plasma fibrinogen is normal. Plasma vWF antigen and plasma vWF rustromycin cofactor activity (VwF:RCo) are further determined.
If VwF:Ag and VwF:RCo are reduced, VWD should be considered and further typing diagnosis of VWD should be done. VWD can be divided into type 1, type 2 and type 3, of which type 1 and type 3 are partial and completely deficient in VWF, type 2 is a functional defect of VWF, and type 1 is the most common.
This condition needs to be differentiated from hemophilia A because the treatment of the two is different. Hemophilia A is basically a disease in boys, muscle and joint bleeding, bleeding after trauma, APTT is prolonged and the number and function of vWF are normal.
Type 1 VWD can be treated with 1-desamino-8-dextrol-arginine vasopressin (DDAVP, coagulation), and in patients with various types of VWD with bleeding episodes or perioperative periods, as well as patients who do not respond to DAVP therapy, blood-derived VWF-containing FVIII. concentrates are selected, and if conditions limit the use of cryoprecipitates or fresh plasma.
Vascular hemophilia is not uncommon, and in the past, the diagnosis of vWF could not be determined in most places, resulting in a delay in diagnosis. Our hemophilia screening program not only measures vWF, but also can also perform plasma coagulation factor VIII., IX. activity and vWF antigen determination at the same time. If your child often has skin ecchymosis and nasal bleeding, please check in time to avoid long-term blood loss and cause anemia, and also prevent trauma or bleeding after surgery!
Edited by: Yeah Reviewer: Xiao Ran