Although AHA is thus clinically and economically an important disorder, it is often unrecognized or misdiagnosed as other acquired hemorrhagic disorders, such as disseminated intravascular coagulation (DIC) and acquired inhibitors against von Willebrand factor (acquired von Willebrand syndrome [9]) and factor XIII (acquired factor XIII deficiency [10]). Here, VWF is linked to autoimmune hemolytic anemia.