Replacement therapy is a treatment that replaces something
that's missing or not working well in your body. People with
von Willebrand's disease don't have von Willebrand
factor, or it doesn't work well enough to help clot their blood. So shots
(injections) of
plasma and clotting factor VIII plus von Willebrand
factor can be used as replacement therapy. Doctors prescribe this type of
therapy to people who do not respond well to desmopressin medicine or who have
a very severe form of von Willebrand's disease. Patients often learn to inject
themselves at home, but a doctor or nurse can give the shots too.
Plasma is usually taken from blood donations. In the United States,
donated blood is carefully screened. Blood with any viruses, such as the human
immunodeficiency virus (HIV) or
viral hepatitis B, is not used. The chance of getting
one of these viruses from plasma is extremely low. Most forms of plasma, such
as Humate-P and Alphanate, are screened and treated for viruses.
Replacement therapy doesn't always work well, because the body may kill
the newly introduced von Willebrand factor.
Research is being done
on new medicines that contain a greater amount of von Willebrand factor.