A recent article in the National Hemophilia Foundation news quotes the Blood Transfusion journal’s report on the results of a study conducted under the lead of Dr. Flora Peyvandi, Medical Director, Milan, Italy. The results confirm the benefit of secondary long-term prophylaxis with von Willebrand factor therapy (vWF)/factor VIII (FVIII) for patients who have been diagnosed with severe vWD. Secondary prophylaxis is recommended when a patient has had several bleeding occurrences in the same area.
vWD is an inherited disease and is considered to be the most common blood-clotting disorder in humans. However, some forms of the disease can be acquired through other disorders. It is a lifelong disease with no cure as yet. Erik Adolf von Willebrand, a Finnish physician, first identified the disease in 1926.
vWD occurs through a gene that controls von Willebrand factor (vWF), a protein that is required for blood clotting. Low levels or malfunction of these proteins precludes platelets from adhering to the walls of blood vessels after an injury or prevents clumping together to assist blood clotting. This can result in excessive bleeding.
Another substance that assists blood clotting is factor VIII. vWD patients’ levels are generally low in factor VIII. Therapy includes short or long term prophylaxis.
Some similarities exist between hemophilia and vWD whereby patients with either disorder may exhibit a deficiency of factor VIII and may require factor VIII/vWF concentrates.
Hemophiliacs, on the other hand, may have a deficiency of either factor VIII or factor IX. The disease affects mostly males whereas vWD affects both males and females.
Symptoms of vWD
Severe bleeding is associated with vWD and differs among individuals. Symptoms may include:
- Continuous, lengthy nosebleeds
- Abnormal bleeding after surgery, dental work or injury
- Blood in the stool or urine
- Bruising easily
- Unusually heavy menstrual bleeding
Types of vWD
vWD types are categorized according to a deficiency in the quality or quantity of vWF:
- Type 1 quantitative and most common with mild symptoms
- Type 2 qualitative vWF deficiency with four subtypes
- Type 3 quantitative vWF deficiency with severe symptoms and passed to a child by both parents’ chromosomes
There is a 4th type that is not inherited but is often the result of heart or autoimmune disease. Medications may also be responsible for acquired vWD.
About the Study
The study participants were divided into two groups. All patients were diagnosed with severe vWD. In one group nine patients were treated at each bleeding occurrence (on-demand). The second group of ten patients was treated with vWF/FVIII factor products.
Results of the Study
Twelve patients completed the study. Patients in the on-demand group had much higher bleeding occurrences than the prophylaxis group. However, out of 172 bleeds in the on-demand group, one patient accounted for 112 of the bleeds. The prophylaxis group had 32 bleeds. It was reported that there were no adverse events connected to the factor treatment. Patients treated with vWF/FVIII exhibited less bleeding than patients in the on-demand group.
In conclusion, due to the prevalence of vWD, there is a need to expand on the utilization of prophylaxis with vWF/FVIII therapies as well as possible genetic testing and improved methods of diagnosis.