Возможность получения реагента для определения ристоцетин-кофакторной активности фактора Виллебранда (ФВ:РКФА) из тромбоцитарных концентратов длительного срока хранения

Introduction. Von Willebrand factor (vWF) is an important component of hemostatic system and deviations from the norm of its content or composition are the cause of various types of von Willebrand disease development. Determination of ristoce- tin-cofactor activity of vWF (vWF:RCo) is particularly important for identifying 2A, 2B and 2M types of von Willebrand disease, in which the content of vWF antigen is within the normal range, and vWF:RCo significantly reduced. Aim: to obtain a reagent for the measurement of vWF:RCo from platelet concentrates with a long shelf life, providing correct diagnostics. Materials and methods. Fully functional platelets were obtained from donor platelet concentrates with a shelf life of 7–14 days. Results. We discovered the method for selection of fully functional donor platelets to produce formaldehyde-fixed cells. On the basis of these platelets we developed a reagent that allows to measure vWF:RCo using both aggregation and agglutina- tion methods. The appropriateness was found between the results of vWF determination by both methods with a correlation coefficient 0.96. The aggregation method of measuring vWF:RCo was evaluated by a result of participation in the internation- al program of external quality control UK NEQAS for Blood Coagulation (United Kingdom). Conclusion. It is shown that the use of a reagent obtained from fixed platelets allows for the correct measurement of vWF:RCo. REFERENCES 1. Zubairov D.М. Von Willebrand factor. In: Molecular basis of blood coagulation and thrombus formation: monograph. [Fak- tor fon Villebranda. V kn.: Molekulyarnye osnovy svertyvaniya krovi i tromboobrazovaniya: monografiya]. Kazan’: FEN. 2000: 111–21 (in Russ.). 2. Mannucci P.M., Coppola R. Von Willebrand factor. In: Laboratory techniques in thrombosis — a manual [Eds. J. Jespersen, R.M. Ber- tina, F. Haverkate]. 2nd revised ed. Dordrecht/Boston/London: Kluwer Academic Publishers. 2000: 115–9. 3. Meyer D., Girma J.P. Von Willebrand factor: structure and function. Thromb Haemost. 1993; 70 (1): 99–104. 4. Barkagan Z.S., Momot A.P. Determination of von Willebrand factor on formalized platelets. In: The fundamentals of the diagnosis of hemostasis disorders. [Opredelenie faktora Villebranda na formalinizirovannyh trombocitah. V kn.: Osnovy diagnostiki narushenij gemostaza]. M.: N’yudiamed-AO. 1999: 58–62 (in Russ.). 5. Kitchen S., McCraw A., Echenagucia M. Ristocetin cofactor activity/von Willebrand factor activity (vWF:RCo or vWF:Act). In: Diagnosis of hemophilia and other bleeding disorders: a laboratory manual. 2nd ed. World Federation of Hemophilia. 2010: 83–6. 6. Favaloro E.J. Laboratory evaluation of von Willebrand desease: phenotypic analysis. In: Kitchen S., Olson J.D., Preston F.E. Quality in laboratory hemostasis and thrombosis. Leiden: Wiley-Black- well. 2009: 125–36. 7. Evans R.J., Austen D.E. Assay of ristocetin cofactor using fixed platelets and platelet counting technique. Brit J Hematol. 1997; 37: 289–94. 8. Howard M.A., Firkin B.G. A new tool in the investigation of platelet aggregation. Thromb Diath Haemorrh. 1971; 26: 362–5. 9. Malakhov V.N., Karinova I.N., Zaikin E.V., Dobrovolsky A.B. Interlaboratory variation of the results of coagulation analyzes according to the data of the FC VOC. [Mezhlaboratornaya variaciya rezul’tatov koagulologicheskih analizov po dannym FS VOK]. URL: www.fs-vok.ru/Publications.htm (in Russ.). [Accessed: 28.06.2018].