TY - JOUR T1 - The role of von Willebrand factor alterations in thyroid disorders TT - JF - Ilam-University-of-Medical-Sciences JO - Ilam-University-of-Medical-Sciences VL - 7 IS - 3 UR - http://jbrms.medilam.ac.ir/article-1-507-en.html Y1 - 2020 SP - 47 EP - 61 KW - Haemorrhage KW - Hyperthyroidism KW - Hypothyroidism KW - Thrombosis KW - von Willebrand factor N2 - Thyroid hormones are mediators of various metabolic processes including haemostasis. Von Willebrand is a multimeric glycoprotein with a major role in blood coagulation, participating in platelet adhesion to subendothelial collagen. It is also a carrier protein and stabilizer of circulating factor VIII and a marker of endothelial activation. This review aims to summarize the available data with regards to changes of von Willebrand factor in thyroid disorders, possible pathophysiological mechanisms, and their significance in clinical practice. PUBMED database was used for literature search in the English language over the last 20 years. Von Willebrand factor and coagulation factor VIII seem to have a key role in the pathogenesis of bleeding and thrombosis in thyroid disorders. Clinical hypothyroidism is associated with acquired von Willebrand syndrome due to the reduction of von Willebrand factor synthesis and release into the circulation. The implication of the von Willebrand factor in the prothrombotic environment induced by subclinical hypothyroidism is not clear. Hyperthyroidism increases the thromboembolic risk by increasing the levels of procoagulant agents including the von Willebrand factor. However, the available studies are highly heterogeneous in design and most of them investigate the laboratory changes of von Willebrand factor in patients with thyroid disease without any clinical implication. Patients with haemostatic disorders should be screened for underlying thyroid disease. Von Willebrand factor changes are corrected by restoring thyroid function. However, the implementation of early treatment in subclinical thyroid disorders has not been established. M3 ER -