Abstract
Background: von Willebrand factor multimers (VWF:MM) methodologies are technically difficult, laborious, time consuming, non-standardized and results vary between labs. A first step towards standardization was made by introducing a semi‐automated VWF:MM assay by Sebia (Lisses, France). In addition to qualitative interpretation of multimer patterns, the Sebia PHORESIS software allows quantification of VWF:MM band patterns, thus the percentage of each molecular weight multimer fraction can be calculated. Due to lack of reference values for VWF:MM fractions, results interpretation can be challenging in some cases.
Aims: The aim of this study was to determine reference intervals for low molecular weight (LMW), intermediate molecular weight (IMW) and high molecular weight (HMW) multimers.
Methods: To collect a larger sample size an international cooperation was initiated. We analyzed data from 134 participants (51 males and 83 non-pregnant females) aged 17-69 years. Acceptance criteria: no history of hemorrhagic episodes; no usage of any medication for at least 10 days before blood collection; normal coagulation screening tests; normal VWF screening assay results; written consent provided.
Reference intervals (with 90% confidence intervals) were calculated using a robust method according to the CLSI C28-A3 standard. The study was performed according to the Declaration of Helsinki and was approved by national ethical committees.
Results: After outlier exclusion (n=3), done by Grubs double sided and Tukey methods, a total of 131 samples were analyzed statistically. Results were normally distributed. No significant differences were found between males and females. The proposed reference intervals for VWF:MM are presented in table 1.
Conclusions: Quantification of VWF:MM fractions, in addition to qualitative assessment of VWF:MM patterns, has potential value to aid in differential diagnosis of VWD sub-types. The reference values calculated in this study can be used in future research to establish clinical decision liimits.
Aims: The aim of this study was to determine reference intervals for low molecular weight (LMW), intermediate molecular weight (IMW) and high molecular weight (HMW) multimers.
Methods: To collect a larger sample size an international cooperation was initiated. We analyzed data from 134 participants (51 males and 83 non-pregnant females) aged 17-69 years. Acceptance criteria: no history of hemorrhagic episodes; no usage of any medication for at least 10 days before blood collection; normal coagulation screening tests; normal VWF screening assay results; written consent provided.
Reference intervals (with 90% confidence intervals) were calculated using a robust method according to the CLSI C28-A3 standard. The study was performed according to the Declaration of Helsinki and was approved by national ethical committees.
Results: After outlier exclusion (n=3), done by Grubs double sided and Tukey methods, a total of 131 samples were analyzed statistically. Results were normally distributed. No significant differences were found between males and females. The proposed reference intervals for VWF:MM are presented in table 1.
Conclusions: Quantification of VWF:MM fractions, in addition to qualitative assessment of VWF:MM patterns, has potential value to aid in differential diagnosis of VWD sub-types. The reference values calculated in this study can be used in future research to establish clinical decision liimits.
| Original language | English |
|---|---|
| Article number | PB1574 |
| Number of pages | 2 |
| Journal | Research and Practice in Thrombosis and Haemostasis |
| Volume | 4 |
| Issue number | S1 |
| Publication status | Published - Aug 2020 |
| Event | Congress of the International Society on Thrombosis and Haemostasis (ISTH) - virtual Duration: 12 Jul 2020 → 14 Jul 2020 https://www.isth.org/page/isth2020 https://onlinelibrary.wiley.com/toc/24750379/2020/4/S1 |
Field of Science*
- 3.2 Clinical medicine
Publication Type*
- 3.4. Other publications in conference proceedings (including local)