Time from apheresis platelet donation to cold storage: Evaluation of platelet quality and bacterial growth.

BACKGROUND: Cold storage reduces posttransfusion survival of platelets; however, it can improve platelet activation, lower risk of bacterial contamination, and extend shelf-life compared to room temperature (RT) storage. To facilitate large-scale availability, manufacturing process optimization is needed, including understanding the impact of variables on platelet potency and safety. Short time requirements from collection to storage is challenging for large blood centers to complete resuspension and qualify platelets for production. This study evaluated the impact of time from platelet component collection to cold storage on in vitro properties and bacterial growth. STUDY DESIGN AND METHODS: Double-apheresis platelet components were collected from healthy donors, suspended in 65% PAS-III/35% plasma, and split into 2 equal units. One unit was placed into cold storage within 2 h and the other unit after 8 h. Eight matched pairs were evaluated for 12 in vitro parameters. Twenty-four matched pairs were evaluated with 8 bacterial strains tested in triplicate. Samples were tested throughout 21 days of storage. RESULTS: In vitro properties were not different between 2 and 8 h units, and trends throughout storage were similar between arms. Time to cold storage did not significantly impact bacterial growth, with <1 log10 difference at all timepoints between units. DISCUSSION: Our studies showed that extending time to cold storage from 2 to 8 h from collection did not significantly increase the bacterial growth, and the platelet component quality and function is maintained. The ability to extend the time required from collection to storage will improve blood center logistics to feasibly produce CSPs.

Genetic analysis of West Nile virus isolates from US blood donors during 2002-2005.

BACKGROUND: Since its introduction into North America in 1999, West Nile virus (WNV) has spread rapidly across United States (US). OBJECTIVE: To genetically analyze WNV isolates from US blood donors during 2002-2005. STUDY DESIGN: Full-length nucleotide (NT) sequences of WNV isolates from 23 US volunteer blood donors of different geographic areas from 2002 to 2005 were determined and analyzed. RESULTS: Results indicated an overall lack of geographic pattern to WNV in US. Analyses of the viral genetic diversity demonstrated that the WNV evolved at approximately five NT substitutions and 0.8 amino acid (AA) mutations per genome per year. Comparison of the functional sequences of WNV genome showed a higher evolution rate in the coding region than in the non-coding region. Furthermore, a greater diversity was observed in the nonstructural proteins as compared to the structural proteins. Sequence alignment analysis revealed that the rapid spread of WNV in US was accompanied by the establishment of a dominant genetic variant with 11 conserved NT mutations. CONCLUSIONS: The establishment of a dominant genotype across US and the displacement and possible extinction of earlier progenitor genotypes appears to have resulted from the accumulation and fixation of 11 nucleotide mutations throughout the coding region of WNV genome.