What is true about Von Willebrand factor disease type IIA?

• A. Decreased platelet count with normal multimers
• B. Decreased large/medium multimers with normal platelet count
• C. Increased large multimers
• D. No change in multimeric forms

Answer: (B)

Von Willebrand factor (vWF) disease type IIA is characterized by a specific deficiency in von Willebrand factor along with an abnormal distribution of its multimers. In type IIA, there is typically a decrease in the larger and medium-sized multimers of vWF, which are crucial for proper platelet adhesion and function. This condition results from the abnormal processing of vWF, leading to a reduction in these large multimers, while the smaller forms are often present at normal levels.

The accurate understanding of this condition is essential for diagnosis and treatment because the decreased availability of large/medium multimers adversely affects hemostasis. In contrast, the platelet count usually remains normal in type IIA, which is significant in differentiating it from other hematological conditions that may present with a decreased platelet count.

Recognizing these characteristics is crucial for managing patients with vWF disease type IIA appropriately, as treatment may focus on correcting the functional deficit rather than merely addressing platelet levels.