Protecting the blood supply from emerging pathogens: the role of pathogen inactivation.

As a consequence of the many blood-safety interventions introduced since the mid-1980s, the major causes of transfusion-associated mortality have shifted from being mainly due to transfusion-transmitted infections (TTIs) to being mainly due to non-infectious serious events such as TRALI, hemolytic reactions, transfusion overload, and graft versus host disease. Thus, TTIs now account for only 10 to 15% of all transfusion associated mortalities! Relevantly, manufacturers of purified plasma protein fractions have, over the same time period, shown that pathogen inactivation technologies can be successfully implemented resulting in little or no transmission of HIV, HCV or HBV since the late 1980s. These technologies, however, cannot be applied to cellular blood components. Thus, new technologies have evolved over the past decade to treat cellular blood components as well as plasma. These technologies, particularly those involving plasma and platelets, have begun to be used in Europe and this proactive paradigm has evolved to become a potential pre-emptive approach for ridding the blood supply of most TTIs (virus, bacteria, and protozoa). However, in order for pathogen inactivation technologies to become widely accepted, they must be shown to be both cost effective and not associated with new risks to recipients!