Comparison of assays measuring extracellular vesicle tissue factor in plasma samples: communication from the ISTH SSC Subcommittee on Vascular Biology.
J Thromb Haemost
; 22(10): 2910-2921, 2024 Oct.
Article
in En
| MEDLINE
| ID: mdl-38925490
ABSTRACT
BACKGROUND:
Scientific and clinical interest in extracellular vesicles (EVs) is growing. EVs that expose tissue factor (TF) bind factor VII/VIIa and can trigger coagulation. Highly procoagulant TF-exposing EVs are detectable in the circulation in various diseases, such as sepsis, COVID-19, or cancer. Many in-house and commercially available assays have been developed to measure EV-TF activity and antigen, but only a few studies have compared some of these assays.OBJECTIVES:
The International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Subcommittee on Vascular Biology initiated a multicenter study to compare the sensitivity, specificity, and reproducibility of these assays.METHODS:
Platelet-depleted plasma samples were prepared from blood of healthy donors. The plasma samples were spiked either with EVs from human milk or EVs from TF-positive and TF-negative cell lines. Plasma was also prepared from whole human blood with or without lipopolysaccharide stimulation. Twenty-one laboratories measured EV-TF activity and antigen in the prepared samples using their own assays representing 18 functional and 9 antigenic assays.RESULTS:
There was a large variability in the absolute values for the different EV-TF activity and antigen assays. Activity assays had higher specificity and sensitivity compared with antigen assays. In addition, there was a large intra-assay and interassay variability. Functional assays that used a blocking anti-TF antibody or immunocapture were the most specific and sensitive. Activity assays that used immunocapture had a lower coefficient of variation compared with assays that isolated EVs by high-speed centrifugation.CONCLUSION:
Based on this multicenter study, we recommend measuring EV-TF using a functional assay in the presence of an anti-TF antibody.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Thromboplastin
/
Extracellular Vesicles
Limits:
Humans
Language:
En
Journal:
J Thromb Haemost
Journal subject:
HEMATOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Country of publication: