Pathogen reduction in blood components: current technologies and future trends

Abstract

Pathogen reduction in blood components represents a proactive approach in the prevention of spreading blood-borne pathogens via transfusion. Solvent-detergent pathogen reduction technology has been in routine use for more than two decades. Most current techniques use molecules which target viral, bacterial, protozoan or leukocyte nucleic acids and, with subsequent illumination, disable their replication. Beside pathogen reduction effect, some techniques successfully inactivate leukocytes, thus lowering the number of adverse reactions caused by them. Pathogen reduction system is expected to selectively reduce pathogen load while simultaneously preserving blood component function. This aim is very ambitious and still not attained. The technology must be non-toxic, must not form neoantigens and must preserve clinical function of blood components. Four systems currently used in Europe are: solvent/detergent (SD) pathogen reduction technology, methylene blue (MB) plus visible light reduction technology, amotosalen plus UVA light and riboflavin plus UV light technology. The technology which utilizes amotosalen and UV light for pathogen reduction in platelet components was introduced into routine practice of the Blood Transfusion Centre of Slovenia in 2008. Each method has its advantages and disadvantages. So far, a system for universal inactivation of all three components has not been developed. Studies for whole blood inactivation system are ongoing. In view of the low risk in transmitting classical transfusion diseases, this approach will be the only pathogen reduction technology the implementation of which will be justifiedwith respect to cost/benefit issues. The other question is how long can we wait and if we can wait at all? In developing countries such a technology can mean difference between life and death. We will present the mechanisms of action, processing, toxicology profile, pathogen reduction efficacy, adverse effects and clinical experience of the methods mentioned above.