Autoimmune Antibody and Coagulation Testing (CPB 0662, reviewed 2026-10-14)
Aetna considers the PF4-dependent P-selectin expression assay (PEA) for members with suspected heparin-induced thrombocytopenia who need additional testing, and several von Willebrand factor assays, medically necessary when criteria are met. Those assays include VWF collagen binding for suspected type 2A, 2B or 2M von Willebrand disease, VWF factor VIII binding for suspected type 2N, and VWF multimer analysis with ristocetin-induced platelet aggregation to determine the type in diagnosed members. Antiprothrombin antibody testing, detection of elevated factor VIII and VWF levels for acute ischemic stroke risk, and VWFpp/VWF:Ag for type 1C von Willebrand disease are considered experimental, investigational or unproven because their clinical value has not been established.