Table 4: Laboratory Diagnosis of Von Willebrand Disease by Type

Table 4:
Laboratory Diagnosis of Von Willebrand Disease by Type
Tests	Types of Von Willebrand Disease
Tests	1	2A	2B	2M	2N	3
Von Willebrand factor antigen	↓	↓ or N	↓	↓ or N	N	↓↓↓
Ristocetin cofactor activity	↓	↓↓	↓↓	↓	N	↓↓↓
Factor VIII activity	↓↓	↓ or N	↓ or N	↓ or N	↓↓	↓↓↓
High-molecular-weight vWF multimers	N	↓↓	↓	N	N	↓↓↓
Ristocetin-induced platelet aggregation	↓ or N	↓	↑	↓	N	↓↓↓
N = normal, ↓ = mildly decreased, ↓↓ = moderately decreased, ↓↓↓ = markedly decreased, ↑ = increased