Factors related to the development of acquired von Willebrand syndrome in patients with essential thrombocythemia and polycythemia vera.
Eur J Intern Med 2017;
41:49-54. [PMID:
27919526 DOI:
10.1016/j.ejim.2016.11.011]
[Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 02/01/2023]
Abstract
OBJECTIVE
We characterized acquired von Willebrand syndrome (AVWS) among essential thrombocythemia (ET) and polycythemia vera (PV) patients.
METHODS
A review of patients with ET or PV evaluated for AVWS.
RESULTS
Of 116 patients with ET, 64 (55%) developed AVWS; of 57 with PV, 28 (49%) developed AVWS. Median platelet counts of ET and PV patients who developed AVWS were 920×109/L and 679×109/L, respectively (P=0.01). Of patients who developed AVWS, 69.5% had platelet counts below 1000×109/L. Bleeding was more common in patients with AVWS, among both ET and PV patients (P<0.001). VWF:RCo levels and VWF:RCo/VWF:Ag ratio were lower among JAK2 V617F positive- vs. JAK2 V617F negative- ET patients (P=0.02 and P=0.002, respectively); whereas VWF:Ag levels were comparable (P=0.96). ET patients harboring the JAK2 V617F mutation were more likely to develop AVWS than were calreticulin-positive patients (70.3% vs. 45.7%, P=0.02), despite lower platelet counts (median 773 vs. 920×109/L, P=0.05). In multivariable analysis, younger age (P=0.002), platelet count (P<0.001), hemoglobin level (P=0.01) and JAK2 V617F mutation (P=0.01) independently predicted the development of AVWS among ET patients; whereas only platelet count predicted its development among PV patients (P<0.001).
CONCLUSION
Among ET and PV patients, AVWS was common and associated with higher bleeding rates and higher platelet count; nonetheless, most AVWS patients had platelet counts under 1000×109/L. Thus, AVWS screening should be included in routine assessment of ET and PV patients. Among ET patients, JAK2 V617F was a main driver for the development of AVWS.
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