ADAMTS-13 activity and antigen in commercial von-Willebrand-factor (VWF) concentrates
Abstract number: PP-WE-087
Scharrer1 I., Vigh1 T., Böhm-Weigert1 M.
11Department of Hematology and Haemostaseology, University Hospital Mainz, Mainz, Germany
How-to-cite Scharrer I, Vigh T, Böhm-Weigert M. ADAMTS-13 activity and antigen in commercial von-Willebrand-factor (VWF) concentrates. Journal of Thrombosis and Haemostasis 2009; Volume 7, Supplement 2: Abstract PP-WE-087
Introduction: The aim of this study was to evaluate the content of ADAMTS-13 act. and ag in commercial VWF conc.. Three conc. (labelled A, B and C, respectively) were tested.
Materials and Methods: ADAMTS-13 act. was tested by measuring the capacity of the conc. for auto-proteolysis both in the presence and in the absence of neutralising ADAMTS-13 auto-antibodies, according to the method of Böhm et al., 2002. This test enables the detection of very low ADAMTS-13 act., which would not be detected by utilizing standard methology.
Results: Residual VWF:RCo of conc. A was 138%, 111% and 7% in the presence of aTTP-plasma (with inhibitor), cTTP-plasma (without inhibitor) and NP, respectively. Residual VWF:RCo of conc. B was 104% in the presence of aTTP-plasma and only 16% in the presence of cTTP-plasma, which was similar to VWF:RCo in the presence of NP (10%). The residual VWF:RCo of conc. C was 63% in the presence of aTTP-plasma and was reduced to 36% in the presence of cTTP-plasma and further reduced to 10% in the presence of NP. The ADAMTS-13 ag content in conc. B and C were 13.4 ng/I.E.U VWF:RCo and 1.6 ng/I.E.U VWF:RCo, respectively. ADAMTS-13 ag was not detectable in conc. A.
Conclusions: The auto-proteolysis in the presence of cTTP-plasma, but not in the presence of aTTP-plasma hints at ADAMTS-13 act.. Conc. B seems to contain the highest amounts of ADAMTS-13 act. and ADAMTS-13 ag. Conc. B is followed by conc. C. Conc. A contains only small traces of ADAMTS-13 act. and non-detectable levels of ADAMTS-13 ag. The results demonstrate that conc. B and C should not be used as VWF substrates in ADAMTS-13 act. assays. Furthermore the content of ADAMTS-13 act. may has the potential to affect stability and recovery of VWF conc.
Disclosure of interest: none declared.
To cite this abstract use the following format:
Journal of Thrombosis and Haemostasis 2007; Volume 5, Supplement 2: abstract number
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