Chemical and Biological Mechanisms of Pathogen Reduction Technologies

Abstract

Within the last decade new technologies have been developed and implemented which employ light, often in the presence of a photosensitizer, to inactivate pathogens that reside in human blood products for the purpose of transfusion. These pathogen reduction technologies attempt to find the proper balance between pathogen kill and cell quality. Each system utilizes various chemistries that not only impact which pathogens they can inactivate and how, but also how the treatments affect the plasma and cellular proteins and to what degree. This paper aims to present the various chemical mechanisms for pathogen reduction in transfusion medicine that are currently practiced or in development.

Dengue and chikungunya viruses in plasma are effectively inactivated after treatment with methylene blue and visible light

“…A similar trend has been observed previously for WNV . The different viral reduction profiles could be due to different methods used for detecting and quantifying the viruses after treatment or deviation in the number of guanine residues in the viral genome potentially causing variances in the inactivation process …”

Inactivation of viruses in platelet and plasma products using a riboflavin‐and‐UV–based photochemical treatment

“…Most PRT processes are not effective against spore‐forming bacteria and do not remove prions from the donated product. PRT‐treated products may also induce oxygen‐mediated damage to pathogens, proteins, and cellular components . In addition, the inactivation of a pathogen in the donated product may not reach 100%; however, no detection system is 100% effective at preventing transfusion transmission of a pathogen either.…”

Treatment of Platelet Products with Riboflavin and UV Light: Effectiveness Against High Titer Bacterial Contamination

“…white blood cells). Exposure to UV light activates riboflavin, causing a chemical alteration to functional groups of the nucleic acids (primarily guanine bases), thus preventing replication and/or transcription of the nucleic acids and leaving the organism inactivated 13 . Anucleated cells like platelets and red blood cells are not affected by the riboflavin chemistry due to the lack of nucleic acid.…”