VWF and von Willebrand disease 1: Instead, the panel recommended that patients with abnormal bleeding and plasma levels in the 30 to 50 IU/dL range should also be diagnosed with type 1 VWD rather than “Low VWF.” The rationale for integrating the previous Low VWF and type 1 subgroup into a single group was that patients with VWF levels in the 30 to 50 IU/dL range and bleeding symptoms would find it easier to access clinical care in some jurisdictions (notably the United States) if they were registered with a formal diagnosis of type 1 VWD rather than Low VWF [22].