Acquired von Willebrand factor abnormalities in myeloproliferative disorders and other hematologic diseases: a retrospective analysis by a single institution.

BACKGROUND AND OBJECTIVES Acquired von Willebrand syndrome (AVWS) is a rare acquired disorder. In most cases it is associated with lymphoproliferative disorders and monoclonal gammopathies, while less frequently myeloproliferative disorders (MPD) are involved. Although bleeding is the most important symptom, thrombotic complications have also been observed in cases associated with MPD. Our aim was to review the clinical and laboratory findings in AVWS patients from a single institution. DESIGN AND METHODS The records of 99 patients with AVWS were reviewed to identify the underlying diseases, the symptoms and the laboratory parameters. RESULTS In 75% of cases the AVWS was associated with MPD. The most frequent pattern was type 2 (67.7%). Abnormalities of bleeding time, factor VIII levels or platelet retention to glass beads were observed in 83.8% of cases. Bleeding was present in 38.4% of patients, more frequently in the not-MPD-associated (58.3%) vs. MPD-associated cases (32%) (p=0.022), with a significant predominance in females, irrespective of the underlying disease (p=0.0007). In 32% of patients with MPD, thrombotic manifestations, mostly microvascular and arterial episodes, were observed. INTERPRETATION AND CONCLUSIONS AVWS in MPD seems to be mainly a laboratory diagnosis, without clinical symptoms in most cases, although bleeding as well as ischemic events can be present. In contrast, AVWS in not-MPD-associated cases is most frequently associated with severe bleeding symptoms. Performing appropriate laboratory tests may be useful for screening for AVWS.