Changes in von Willebrand factor level and von Willebrand activity with age in type 1 von Willebrand disease. (10th March 2015)

• Record Type: Journal Article
• Authors: Rydz, N.; Grabell, J.; Lillicrap, D.; James, P. D.
• Is Part Of: Haemophilia. Volume 21:Number 5(2015:Sep.)
• Page Start: 636
• Page End: 641
• Publication Date: 2015-03-10
• Subjects: Hemophilia -- Periodicals; 616.1572005
• DOI: 10.1111/hae.12664
• Languages: English
• ISSNs: 1351-8216

Abstract

<abstract abstract-type="main" id="hae12664-abs-0001"> <title>Summary</title> <p>In a normal population, VWF plasma levels (VWF:Ag) and VWF activity (VWF:RCo) increase by approximately 0.17 and 0.15 IU mL<sup>−1</sup> per decade, but the influence of age is unknown in patients with type 1 von Willebrand disease (VWD). In a retrospective cohort study, the medical records of 31 type 1 VWD patients over the age of 30, who had been followed for ≥5 years, were reviewed for baseline clinical data and previously performed VWF:Ag, VWF:RCo and factor VIII levels (FVIII:C). VWF multimer analysis was normal in 28/31 cases performed. Mean age at diagnosis was 33 (range 16–60 years), and duration of follow‐up ranged from 5 to 26 years (mean 11 years). Patients had 2–10 time points of VWD testing (mean of 5.2). The mean VWF:Ag, VWF:RCo and FVIII:C at time of diagnosis were 0.44 IU mL<sup>−1</sup> 0.34 IU mL<sup>−1</sup> and 0.75 IU mL<sup>−1</sup>. At last follow‐up, the mean VWF:Ag, VWF:RCo and FVIII:C were significantly increased to 0.71 IU L<sup>−1</sup>, 0.56 IU mL<sup>−1</sup> and 0.90 IU mL<sup>−1</sup> (<italic>P </italic>≤ 0.001, <0.001, and 0.0081 respectively). Here 18/31 patients had VWF:Ag, VWF:RCo and FVIII: C levels that increased into the normal range. The rate of change in VWF:Ag, VWF:RCo and FVIII was 0.30 IU mL<sup>−1</sup> (0.21–0.39, CI 95%, <italic>P </italic><<italic> </italic>0.0001), 0.20 IU mL<sup>−1</sup> per decade (0.13–0.27, CI 95%<italic>, P = </italic>0.0001) and 0.20 IU mL<sup>−1</sup> (0.11–0.29, CI 95%<italic>, P </italic>=<italic> </italic>0.0011). Patients with type 1 VWD experience age‐related increases to VWF:Ag and VWF:RCo which can result in normalization of VWF levels. Further studies are required to determine if the bleeding phenotype resolves with the increases in VWF:Ag and VWF:RCo levels.</p> </abstract>