Effects of storage temperature on hematopoietic stability and microbial safety of BM aspirates.

Bone marrow (BM) remains a common source for hematopoietic SCT. Due to the transcutaneous approach, contamination with skin bacteria is common. The delay between harvest and transfusion can be considerable, potentially allowing for bacterial proliferation. The optimal transportation temperature, specifically with respect to bacterial growth and consequences thereof for hematopoietic quality, remain undefined. For 72 h, 66 individual BM samples, non-spiked/spiked with different bacteria, stored at 20-24 °C room temperature (RT) or 3-5 °C (cold), were serially analyzed for hematopoietic quality and microbial burden. Under most conditions, hematopoietic quality of BM was equal or better at RT: Typical BM contaminants (P. acnes and S. epidermidis) and E. coli were killed or bacterial proliferation was arrested at RT; hematopoietic quality was not impacted by the contamination. However, several pathogenic bacteria not typically found in BM (S. aureus and K. pneumoniae) proliferated dramatically at RT and impaired hematopoietic quality. Bacterial proliferation was arrested in the cold. The overwhelming majority of BM samples, that is, those that are sterile or contaminated only with skin commensals, will benefit from transportation at RT. Those bacteria that proliferate and perturb hematopoietic quality are not typically found in BM. Our data support recommendations for RT transportation and storage of BM.

Evaluation of two, commercial, multi-dye, nucleic acid amplification technology tests, for HBV/HCV/HIV-1/HIV-2 and B19V/HAV, for screening blood and plasma for further manufacture.

BACKGROUND: The cobas TaqScreen MPX Test, version 2.0, a multiplex, multi-dye nucleic acid amplification technology (NAT) test from Roche was evaluated by two European Blood Banks, the German Red Cross Blood Donor Service, Frankfurt, Germany and Centro de Hemoterapia y Hemodonación de Castilla y León, Valladolid, Spain. In addition, the cobas TaqScreen DPX Test was evaluated for the simultaneous detection and quantitation of parvovirus B19 and the detection of hepatitis A virus (HAV). STUDY DESIGN AND METHODS: The performances of the two tests were evaluated regarding the analytical sensitivity, the reproducibility of the tests using samples containing low concentrations of each virus and cross-contamination using samples containing high titres of virus. RESULTS: The analytical sensitivity of the MPX Test, version 2.0, obtained by the German Red Cross Blood Donor Service was 1·1, 3·9 and 43·3 IU/ml for HBV, HCV and HIV-1, respectively. The comparable analytical sensitivity at Centro de Hemoterapia y Hemodonación de Castilla y León was 3·5, 17·6 and 50·6 IU/ml for HBV, HCV and HIV-1, respectively. The analytical sensitivity of the DPX test determined by the German Red Cross Blood Donor Service was 0·6 and 3·8 IU/ml for HAV and B19. CONCLUSION: These multiplex and multi-dye blood screening assays represent a flexible NAT screening system for mini-pools between 6 and 96 samples per pool and fulfil all requirements of the European Pharmacopoeia for HCV and B19V testing of plasma for fractionation. The inclusion of a new multi-dye technology means discriminatory assays are no longer required for either test thus improving workflow, turn-around time and minimize the risk of obtaining a reactive result for which the virus cannot be identified.

Oxygen measurements in platelet fluids - a new non-invasive method to detect bacterial contaminations in platelets.

BACKGROUND: The residual risk for bacterial contamination in blood components especially in platelets is one to two orders of magnitude higher than for transfusion relevant viral infections. The majority of all bacterial transmitted fatalities occurred at the end of platelet shelf life. Therefore, the maximum shelf life of platelet concentrates (PC) was reduced to 4 days after blood donation in Germany in 2008. METHODS: A new continuous non-invasive bacterial detection method was developed by O(2) measurements in the platelet fluids and tested with 10 transfusion relevant bacteria species. RESULTS: The bacterial concentration at the time point of a positive signal of PreSense O(2) ranged between 10(2) and 10(5) CFU mL(-1) . Harmful transfusion-transmitted bacterial infection would have probably been prevented by this novel technology. Only strict anaerobic bacteria strains like Clostridium perfringens were not detected within the study period of 72 h. CONCLUSIONS: The described non-invasive bacterial detection method represents a new approach to prevent transmission of bacterial infection in platelets. The method is characterised by the advantage that all investigations can be performed until right up to the time of transfusion, and therefore, reduce the risk for sample errors to a minimum.

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.

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.

Sensitivity and specificity of Anti-HBc screening assays--which assay is best for blood donor screening?

Compared to HIV and hepatitis C virus, the residual infectious risk of hepatitis B virus (HBV) posed by blood products is about 10 times higher. In addition to HBsAg testing, screening for anti-HBc was recommended by the German Advisory Committee Blood in March 2005. Prevalence of anti-HBc in German blood donors was investigated at five test sites located in different geographic regions. In total, 12,000 blood donors were screened for anti-HBc by PRISM HBcore, and a statistically representative number of these were tested with Abbott Murex anti-HBc total, bioMérieux Hepanostika anti-HBc uniform, Bio-Rad Monolisa anti-HBc PLUS and Dade Behring Enzygnost anti-HBc. Anti-HBc repeat reactive samples were tested for anti-HBs, anti-HBe and HBV DNA by individual donation NAT. The mean prevalence of anti-HBc was 1.75% in donors that had not been tested for anti-HBc in the past. The percentage of anti-HBs in anti-HBc repeat reactive donors was 93.7%. Samples that were additionally reactive for anti-HBe were anti-HBc reactive in all tested assays. The sample to cut-off (S/Co) values for anti-HBc were lower (competitive assays) in samples that were also positive for anti-HBe, when compared to samples that were only anti-HBc reactive. Most commercially available anti-HBc assays provide sufficient sensitivity for routine screening purposes, and lacking specificity is no longer a serious issue for most of them. Assay differences were recognized for samples that were anti-HBc only reactive. The overall loss of 1.75% of positive testing donors can be significantly reduced to 0.45% by implementation of re-entry procedures for donors with an anti-HBs titre of over 100 IU/l and negative by sensitive ID-NAT.

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.