Dr Albert Farrugia, Australia
Plasma may be procured for use as a therapeutic product or as a raw material for manufacture of other products, and may be collected as a by-product of whole blood, or as a plasma donation from apheresis. When collected for fractionation, the quality and safety of the plasma are intimately linked to the quality and safety of the manufactured plasma derivatives.
High quality plasma can be obtained either from whole blood or from plasmapheresis; quality can, however, be adversely affected by poor storage conditions after collection. Quality standards for plasma for fractionation are necessarily different than for plasma for transfusion and, with modern fractionation methods, certain quality aspects become less relevant.
Very often a three-pronged approach is used to ensure the safety of biological products:
• selection of appropriate raw materials (donors and cell lines);
• testing of raw materials (screening and viral tests); and
• appropriate action during processing (viral inactivation and product integrity).
Recent technological advances, such as nucleic acid testing (NAT), are used for testing plasma pools for fractionation. However, although this decreases the load of known viruses, viral inactivation procedures are more important in ensuring the viral safety of plasma derivatives. NAT, on the other hand, is more likely to improve the safety of fresh blood components in relation to viruses that are not screened for at blood banks.