Extension of platelet shelf life from 4 to 5 days by implementation of a new screening strategy in Germany.

BACKGROUND: The Paul-Ehrlich-Institute analysed all fatalities due to bacterial infections between 1997 and 2007. Thereafter, the platelet shelf life was reduced to a maximum of 4 days after blood donation because the majority of all cases of severe transfusion-transmitted bacterial infections occurred with day 5 platelets. The current study compares the analytical sensitivity and the diagnostic specificity of four rapid bacterial detection procedures. METHODS: Nine transfusion-relevant bacterial strains were spiked in pooled platelets or apheresis platelets at a low concentration (10 CFU/bag). Samples were collected after day 3, day 4 and day 5 and investigated by four rapid bacterial detection methods (modified BacT/ALERT, Bactiflow, FACS method and 16s DNA PCR methods). RESULTS: Seven out of nine bacterial strains were adequately detected by BacT/ALERT, Bactiflow and PCR in apheresis platelets and pooled platelets after sample collection at day 3, day 4 and day 5. For three bacterial strains, analytical sensitivity was reduced for the FACS method. Two bacterial strains did not grow under the storage conditions in either pooled or apheresis platelets. CONCLUSIONS: A late sample collection on day 3, day 4 or day 5 after blood donation in combination with a rapid bacterial detection method offers a new opportunity to improve blood safety and reduce errors due to sampling., BacT/ALERT, Bactiflow or 16s ID-NAT are feasible for late bacterial screening in platelets may provide data which support the extension of platelet shelf life in Germany to 5 days.

465 nm laser sources by intracavity frequency doubling using a 49-edge-emitters laser bar.

A compact blue laser was generated by intracavity frequency doubling based on quasi-phase-matched second-harmonic generation (SHG) in a MgO-doped periodically poled lithium niobate bulk crystal. A 49 single-transverse-mode edge-emitters laser bar with antireflective coating was used as a pump source. An optical output power of 1.2 W SHG of blue lights at 465 nm is generated at 45 A injection current, equivalent to an overall wall-plug efficiency of 1.33%.

Accumulation of soluble inflammatory mediators between blood donation and pre-storage leucocyte depletion.

BACKGROUND AND OBJECTIVES: Leucocyte-derived cytokines accumulate in stored whole blood. Pre-storage leucocyte depletion has reduced cytokine levels and, consequently, febrile non-haemolytic transfusion reactions. As leucocyte filtration and component separation can be performed until 24 h after donation, we hypothesized that within this time, inflammatory cytokines might accumulate. MATERIALS AND METHODS: Serial plasma samples were collected 4, 10 and 20 h after donation and cytokine concentrations were measured. RESULTS: Interleukin-8 increased > 20-fold and soluble CD40 ligand > sixfold during the observation time, less pronounced changes for several other mediators were also observed. CONCLUSION: Leucocyte depletion within 10 h of blood donation will reduce the concentrations of pyrogenic mediators.

Plasma quality after whole-blood filtration depends on storage temperature and filter type.

The study evaluated the quality of plasma obtained after whole-blood filtration with four different polyester filters and one polyurethane filter. The activities of coagulation factors and proteinase inhibitors were not or only negligibly affected by filtration, in all experiments. Filtration did not increase markers of clotting and fibrinolysis. Only a strong neutrophil and complement activation was observed, which depended on the type of filter and whole-blood storage conditions. However, as neutrophil elastase-specific degradation products did not increase and the complement-derived anaphylatoxin C3a was found in its inactivated form, C3a-desArg, these filtration-dependent changes apparently have little impact on the therapeutic quality of whole-blood-filtered fresh frozen plasma for transfusion.