More from Kim Kinney on her patient with acquired von Willebrand syndrome:
I have some follow-up to the case I sent your way today. This patient was diagnosed with GI angiodysplasia, which has been listed in some references as a disorder associated with acquired von Willebrand disease. Our pathologist has a reference that quotes an ELISA test for antibodies directed agains VWF in the patient. Are you aware of any labs performing such an assay?
Kim, thanks for the follow-up. I’ve only seen VWF inhibitors assayed using a Bethesda titer in which the VWF:RCo provides the endpoint. Blood Center of Wisconsin lists it in their menu. I’ve seen a couple of reports from researchers who coated plates with VWF to assay the inhibitor, but no one seems to offer this as a clinical assay.
There is a good reference from Dr. Sadler’s laboratory at Wash U available as a free download. It is Federici AB, Rand JH, Bucciarelli P, et al. Acquired von Willebrand Syndrome: data from an international registry. Thromb Haemost 2000;84:345-9. It mentions that most of the inhibitors were detected in a mixing study. Geo