Preparation of lyophilized heat-treated cryoprecipitates from a small pool of plasma obtained by apheresis

A minipool process for solvent-detergent treatment of cryoprecipitate at blood centres using a disposable bag system

BACKGROUND AND OBJECTIVES

Single-donor or small-pool cryoprecipitates are produced by blood establishments, mostly in developing countries, for substitute therapy in haemophilia A, von Willebrand disease and fibrinogen deficiency, as well as for the manufacture of fibrin sealant. As cryoprecipitate may be contaminated with pathogenic plasma-borne viruses, there is an urgent need to develop a simple method for the viral inactivation of cryoprecipitate.

MATERIALS AND METHODS

Cryoprecipitate was obtained according to standard procedures. Ten minipools of five or six donations of cryoprecipitate were prepared and subjected, in sterile closed bags, to a viral inactivation treatment using either 2% tri(n-)butyl phosphate (TnBP) for 4 h at 37 degrees C or the combination of 1% TnBP and 1% Triton X-45 for 4 h at 31 degrees C. The cryoprecipitates were subsequently extracted three times in their processing bags by mixing and decantation using 7.5% sterile ricinus oil. The TnBP-treated cryoprecipitates were further subjected to a clarifying centrifugation step at 3800 g for 30 min. The final products were dispensed into individual bags and frozen at -30 degrees C or lower.

RESULTS

The cryoprecipitates treated with either 2% TnBP or 1% TnBP + 1% Triton X-45 showed excellent (> 93%) mean recovery of coagulant factor VIII (FVIII), ristocetin cofactor Von Willebrand factor (VWF:RCo), and clottable fibrinogen activity. Prothrombin time, international normalized ratio and activated partial thromboplastin time increased during solvent-detergent treatment but returned to initial values after oil extractions. The final content of TnBP and Triton X-45 was < 10 and 50 ppm, indicating excellent removal by the oil-extraction procedure.

CONCLUSIONS

Viral inactivation treatment by TnBP, with or without Triton X-45, can be applied to minipools of cryoprecipitate, with good recovery of FVIII, VWF and fibrinogen. The viral inactivation and solvent-detergent removal process can be performed in a closed bag system and using simple blood establishment techniques and equipment. This technology could be considered for the improved viral safety of cryoprecipitate which is used to treat haemophilia A, von Willebrand disease or fibrinogen deficiency, or to prepare fibrin sealant.

Quality control programme for the preparation of small-pool lyophilized heat-treated cryoprecipitates

International and national documents on and standards for quality control have been introduced for Blood Banks. Recently, the Standard Registration Document and a National Health Authority Licence for factor VIII preparations based on the Document were introduced in the Netherlands. In the course of developing a preparation of lyophilized heat-treated cryoprecipitates in our Blood Bank, we used this Standard Registration Document and the good pharmaceutical manufacturing practices to design a quality control protocol. The aim of this protocol was to provide documented evidence on the quality of both our product and the production process. The protocol included the validation or revalidation of individual installations and procedures used during production, validation of the whole process and quality control of routine production. With our quality protocol we have been able to demonstrate that our preparation is consistently of the intended quality.