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Calibration of Lyophilized Standards for Ristocetin Cofactor Activity of von Willebrand Factor (vWF) Requires vWF-Deficient Plasma as Diluent for Dose-Response Curves
| Content Provider | Scilit |
|---|---|
| Author | Rodeghiero, Francesco Castaman, Giancarlo |
| Copyright Year | 1987 |
| Description | Summary: Calibration of local standards for ristocetin cofactor activity of von Willebrand’s factor (vWF : Rcof) against reference preparations is required to achieve a better standardization of this measurement. We have observed that in calibration assays (multiple line parallel bioassay) for vWF : Rcof, measured aggregometrically, the type of diluent used to obtain the dose-response curves exerted a critical influence on the final potency estimation when a fresh-frozen plasma against a lyophilized standard or two lyophilized preparations were to be compared. This pattern was observed with various commercial standards and also with the First International Reference Preparation for Factor VIII-Related Activités in Plasma. The choice of diluent was not relevant if two fresh-frozen plasma preparations were to be calibrated. Systematic experiments using as diluents Trissaline, Tris-buffered-albumin solution or vWF-deficient plasma (vW-plasma) showed that the ratio lyophilized/fresh-frozen preparations was invariably lower with albumin solution than with vW-plasma. Tris-saline partially corrected this discrepancy, but yielded less precise estimates. Preliminary results with cryosuper-natant-plasma seems to indicate that this material is a valid substitute for vW-plasma, but confirmatory experiments are required For the moment, plasma obtained from patients with severe type III vW-disease should be considered the “ideal” diluent for calibration assays involving lyophilized preparations. |
| Related Links | http://www.thieme-connect.de/products/ejournals/pdf/10.1055/s-0038-1646040.pdf |
| Ending Page | 981 |
| Page Count | 4 |
| Starting Page | 978 |
| ISSN | 2567689X |
| DOI | 10.1055/s-0038-1646040 |
| Journal | Thrombosis and Haemostasis |
| Issue Number | 04 |
| Volume Number | 58 |
| Language | English |
| Publisher | Georg Thieme Verlag KG |
| Publisher Date | 1987-12-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Thrombosis and Haemostasis Pharmacology and Pharmacy Von Willebrand Factor Ristocetin Cofactor Assay Lynphilized Standards Von Willcbrand's Disease |
| Content Type | Text |
| Resource Type | Article |
| Subject | Hematology |
