The results from this work suggest that the riboflavin and UV light process may provide up to 98% protection against transfusion of bacterially contaminated units at the most clinically relevant contamination levels (<20 CFUs per product). This compares favorably to the 60% to 66% effectiveness of bacterial culture testing using a 48-hour quarantine period before product release.

The results observed in this study suggest that treating PLT and plasma products with a riboflavin-and-UV-light-based pathogen reduction process could potentially eliminate window period transmission of screened viruses and greatly reduce the risk of transfusion transmission of unscreened viruses.

Contamination of platelet units by bacteria has long been acknowledged as a significant transfusion risk due to their post-donation storage conditions. Products are routinely stored at 22 °C on an agitating shaker, a condition that can promote bacterial growth. Although the total number of bacteria believed to be introduced into a platelet product is extremely low, these bacteria can multiply to a very high titer prior to transfusion, potentially resulting in serious adverse events. The aim of this study was to evaluate a riboflavin based pathogen reduction process against a panel of bacteria that have been identified as common contaminants of platelet products. This panel included the following organisms: S. epidermidis, S. aureus, S. mitis, S. pyogenes, S. marcescens, Y. enterocolitica, B. neotomae, B. cereus, E. coli, P. aeruginosa and K. pneumoniae. Each platelet unit was inoculated with a high bacterial load and samples were removed both before and after treatment. A colony forming assay, using an end point dilution scheme, was used to determine the pre-treatment and post-treatment bacterial titers. Log reduction was calculated by subtracting the post-treatment titer from the pre-treatment titer. The following log reductions were observed: S. epidermidis 4.7 log (99.998%), S. aureus 4.8 log (99.998%), S. mitis 3.7 log (99.98%), S. pyogenes 2.6 log (99.7%), S. marcescens 4.0 log (99.99%), Y. enterocolitica 3.3 log (99.95%), B. neotomae 5.4 log (99.9996%), B. cereus 2.6 log (99.7%), E. coli ≥5.4 log (99.9996%), P. aeruginosa 4.7 log (99.998%) and K. pneumoniae 2.8 log (99.8%). The results from this study suggest the process could help to lower the risk of severe adverse transfusion events associated with bacterial contamination.

No abstract

<b><i>Background:</i></b> The Mirasol system for whole blood (WB) is a non-toxic, non-mutagenic pathogen reduction technology (PRT) that treats WB units with riboflavin (vitamin B₂) and ultraviolet (UV) light to alter nucleic acids, thereby reducing pathogen infectivity and inactivating white blood cells. This study evaluates the quality of red blood cells (RBCs) derived from WB treated with the Mirasol system. <b><i>Study Design and Methods:</i></b> Paired units of WB were collected from 61 healthy donors. One unit per donor was treated with riboflavin and UV light and the other was used as an untreated control. RBCs were processed from the WB units and stored in AS-3 at 1–6°C for 21 days and sampled for in vitro analyses of RBC quality parameters. <b><i>Results:</i></b> Several statistically significant differences were observed between test and control units, but values were overall within normal clinical ranges. After leukoreduction, the residual leukocyte count and RBC recovery met FDA requirements. The RBC units derived from treated WB maintained haemolysis below 1% through 21 days of storage. <b><i>Conclusion:</i></b> RBCs derived from WB treated with the Mirasol system meet accepted FDA guidelines for RBC quality through 21 days of storage at 1–6°C.