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Von Willebrand Disease (VWD)
Part 1: NHLBI Diagnosis Guidelines

Introduction & Clinical Assessment Recommendations

VWD NHLBI Guidelines — Background

Slide 9

May 2011

In 2004 the National Heart, Lung, and Blood Institute (NHLBI) convened an expert panel to develop evidence-based guidelines for VWD diagnosis and management. The panel consisted of 10 physicians and scientists with expertise in adult and pediatric hematology, gynecology, family medicine, public health and epidemiology, laboratory medicine, and basic science. The NHLBI VWD Guidelines project was the first one undertaken for a blood disorder, and required about 4 years for completion.

This Table summarizes etiologic (pathophysiologic) categories and disease associations for AVWS and AVWA. Antibodies to VWF can rarely occur in autoimmune disorders such as lupus (SLE); however, monoclonal IgG or IgM antibodies such as in MGUS (monoclonal gammopathy of undetermined significance) or other dysproteinemias (eg, myeloma, macroglobulinemia, amyloidosis, etc) are relatively common causes of AVWS. Shear-induced VWF proteolysis (believed to be mediated by ADAMTS13) is an increasingly recognized cause of AVWS and AVWA, and can occur in association with severe aortic valvular stenosis (AS), ventricular septal defect (VSD), hypertrophic obstructive cardiomyopathy (HOCM), certain left ventricular assist devices (LVADs), or primary pulmonary hypertension (PPH). Marked thrombocytosis (blood platelets of 1 million or more per microliter) can cause AVWS or AVWA, and mainly occurs in association with essential thrombocythemia (ET) and other myeloproliferative disorders such as polycythemia vera (PV) or AMM (agnogenic myeloid metaplasia with myelofibrosis). Other listed conditions and pathophysiologies of AVWS are relatively rare, but should be considered in the etiologic differential diagnosis of AVWS. Laboratory findings in AVWS and AVWA are similar to those in VWD subtypes, especially Types 1, 2A, or 3. However, laboratory testing results currently cannot readily distinguish between VWD and AVWS (or AVWA); therefore, clinical assessment is essential for this important distinction.

AVWS, and disorders causing it, should be considered in persons found to have abnormal VWD test results and clinical bleeding, but without an antecedent personal or family history consistent with VWD. Conversely, when bleeding occurs in association with one of the causative medical conditions, AVWS should be considered and initial VWD testing performed if indicated.

VWD NHLBI Guidelines — Background


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