Abstract Number: PO158
Meeting: ISTH 2021 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » von Willebrand Factor Biology
Background: von Willebrand factor (vWF) multimer (MM) analyses are required for von Willebrand disease (vWD) classification and to distinguish among subtypes.
Aims: Was to analyse the vWF multimers distribution using the HYDRAGEL VW multimer assay (HS/11VWM, Sebia) in a group of 69 patients diagnosed with von Willebrand disease.
Methods:
Type of sample | LMWM Median (Min-Max) |
IMWM Median (Min-Max) |
HMWM Median (Min-Max) |
|
Type 1 (n=44) | 54.4 (40.7-66.5) |
30.7 (21.8-40.5) |
14.9 (7.6-20.9) |
|
Type 2 (n=23) | 30.8 (9.1-67.7) |
28.0 (12.5-44.6) |
40.2 (10.0-67.8) |
|
Type 2A | 19.2 (9.1-32.9) |
22.8 (12.5-31.9) |
58.0 (40.2-67.8) |
|
Type 2B | 19.3 (12.5-26.0) |
37.2 (29.9-44.6) |
43.5 (29.4-57.6) |
|
Type 2M | 49.4 (38.5-67.7) |
34.2 (22.3-37.2) |
16.4 (10.0-24.3) |
|
Type 2N | 56.8 (47.1-57.7) |
26.3 (16.1-28.5) |
16.9 (14.8-36.8) |
|
Type 3 (n=2) | No multimers | No multimers | No multimers | |
Control group (n=17) | 49.5 (46.1-55.0) |
35.5 (33.5-36.9) |
15.0 (11.5-18.3) |
69 patients (52 female) with a median age of 42 (range 18-83) were classified into three main types and four subtypes of type 2, according to the ISTH/SSC, using the following tests: vWF antigen (vWF:Ag), factor VIII clotting activity (FVIII:C), vWF ristocetin cofactor activity (vWF:RCo), ristocetin-induced platelet aggregation (RIPA), vWF collagen binding activity (vWF:CBA), ACLTop 300. Type 1: 44pts (63.8%), type 2: 23pts (33.3%), type 2A: 11pts (16%), type 2B: 2pts (2.9%), type 2M: 5pts (7.2%), type 2N: 5pts (7.2%), type 3: 2pts (2.9%). The control group consisted of 17 normal healthy adults. Analysis of vWF multimers distribution was made using a HS/11VWM assay (Sebia).
Results:
First we visually evaluated proteins separated into a gel into characteristic bands, then we defined the multimer fractions (LMWM – low molecular weight multimers – peak 1-3; IMWM – intermediate molecular weight multimers – peak 4-7; HMWM >7) using Phoresis software. Densitometric quantification of the fractions were also conducted. A statistically significant difference was observed when comparing HMWM in the group of the patients with type 1 and type 2 (p<0.0001). We also noticed significant differences in HMWM distribution when comparing patients with Type 1 and 2A (p<0.0001); 2A and 2M (p=0.0351); 2A and 2N (p=0.0058). No difference was found in group of the patients classified as type 1, type 2M and type 2N (p=0.8569).
Conclusions: Multimer analysis using the HS/11VWM assay (Sebia) can be proposed as a screening test that helps to make an accurate distinction between normal multimer distribution (types 1, 2M, 2N) and absence of multimers (type 2A).
To cite this abstract in AMA style:
Wojtasinska E, Krupinska O, Malachowska M, Szczepaniak A, Rupa-Matysek J, Gil L. Von Willebrand Factor Multimer Distribution Analysis in a Group of Patients Diagnosed with von Willebrand Disease [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/von-willebrand-factor-multimer-distribution-analysis-in-a-group-of-patients-diagnosed-with-von-willebrand-disease/. Accessed March 22, 2024.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/von-willebrand-factor-multimer-distribution-analysis-in-a-group-of-patients-diagnosed-with-von-willebrand-disease/