BACKGROUND: The large dengue (DENV) and chikungunya (CHIKV) outbreaks observed during the last decade across the world, as well as local transmissions in non-endemic areas are a growing concern for blood safety. The aim of this study was to evaluate and compare the sensitivity of nucleic acid tests (NAT) detecting DENV and CHIKV RNA.
METHODS: Using DENV 1 to 4 International Standards, the limits of detection (LODs) calculated by probit analysis of two NAT assays; the cobas CHIKV/DENV assay (Roche Diagnostics) and the Procleix Dengue Virus Assay (Grifols) were compared. In addition, CHIKV-RNA LOD of the cobas CHIKV/DENV assay was evaluated.
RESULTS: For dengue, the 95% LOD of the cobas assay ranged between 4.10 [CI95%: 2.70-8.19] IU/mL (DENV-2) and 7.07 [CI95%: 4.34-14.89] IU/mL (DENV-4), and between 2.19 [CI95%: 1.53-3.83] IU/mL (DENV-3) and 5.84 [CI95%: 3.84-10.77] IU/mL (DENV-1) for Procleix assay. The Procleix assay had a significant lower LOD for DENV-3 (2.19 vs. 5.89 IU/mL) when compared to the cobas assay (p = 0.005). The 95% LOD for CHIKV-RNA detection of the cobas assay was 4.76 [CI95%: 3.08-8.94] IU/mL.
CONCLUSIONS: The two NAT assays developed for blood donor screening evaluated in this study demonstrated high and similar analytical performance. Subject to an appropriate risk-benefit assessment, they can be used to support blood safety during outbreaks in endemic areas or in non-endemic areas as an alternative to deferring blood donors during local transmission likely to affect the blood supply. The development of multiplex assays is expected to optimize laboratory organization.

BackgroundAwareness of transfusion-transmitted hepatitis E raised in recent years led to the mandatory testing of blood donations in some European countries for hepatitis E virus (HEV) RNA. However, little is known about the epidemiology of HEV infections.AimTo and describe and analyse the epidemiology of HEV infections in blood donors in Germany.MethodsData from routine testing of therapeutic blood products donated between January 2015 and December 2022 at the Uni.Blutspendedienst OWL were analysed at the Institute of Laboratory and Transfusion Medicine, Heart and Diabetes Centre North Rhine-Westphalia. A total of 731,630 allogenic blood donations from 119,610 individual blood donors were tested for HEV RNA in minipools of 96 samples. The HEV RNA-positive donations were analysed for the presence of anti-HEV IgM and IgG. The HEV strains were genotyped and various clinical liver-specific parameters were determined.ResultsA total of 497 HEV-positive blood donations were identified, resulting in a yearly incidence of 1:1,474, from which 78.4% of the donations were RNA-only positive. Increased alanine aminotransferase activity was determined in 26.6% of HEV RNA-positive donors and was associated with the detection of IgG antibodies (1.2% anti-HEV IgM-positive, 11.9% anti-HEV IgM- and IgG-positive and 8.5% anti-HEV IgG-positive). An average incidence of 0.084-0.083% HEV RNA-positive donations in June and July in all years was observed, and a higher proportion of HEV RNA-positive men compared with women. All isolated HEV sequences corresponded to genotype 3.ConclusionOur results underline the necessity of HEV RNA screening in blood donations.

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UNASSIGNED: Evorpacept is a CD47-blocking agent currently being developed for the treatment of various cancers. Interference by evorpacept in pretransfusion compatibility testing has been reported at limited plasma concentrations. Although various mitigation strategies have been proposed, none are practical. This in vitro study assessed evorpacept-induced interference at extended concentrations and investigated the capability of a novel mitigation agent, Evo-NR.
UNASSIGNED: Antibody screening tests were performed on evorpacept-spiked plasma with (anti-E and anti-Jka) or without alloantibodies at evorpacept concentrations up to 2,000 μg/mL using manual gel cards and automated analyzers. Evorpacept-coated red blood cells (RBCs) (rr [ce/ce], Fy[a+b-], S-s+) were tested by direct antiglobulin testing (DAT) and antigen typing using anti-Fyb and anti-S reagents at indirect antiglobulin testing (IAT) phase. Evo-NR was used to resolve the interference in plasma and RBC samples. Flow cytometry was used to assess the mitigation effects.
UNASSIGNED: Evorpacept-spiked plasma showed panreactive interference in antibody screening tests using manual gel cards (2+ to 3+) and automated analyzers (4+). A carryover effect was also observed in the automated analyzers. The use of a 3- to 6-fold molar excess of Evo-NR effectively resolved the interference in the plasma and enabled accurate alloantibody identification. Although the reduction in evorpacept binding to RBCs was identified via flow cytometry, Evo-NR was incapable of resolving the serologic interference observed in DAT and antigen typing at IAT phase.
UNASSIGNED: Evorpacept showed constant panreactivity and a carryover effect at high concentrations. Evo-NR successfully resolved the interference in the plasma samples and could be considered a practical and efficient mitigation solution. Implementation of Evo-NR has the potential to support RBC transfusion for patients undergoing evorpacept treatment.

OBJECTIVE: A plasma transfusion dose should be weight-based (10-20 mL/kg), which equates to three to four units in an average-sized adult; therefore, the transfusion of single units under most circumstances is sub-therapeutic.
METHODS: This retrospective observational study examined the prevalence of single-unit plasma transfusion in adults within a 12-hospital system from 1 January 2018, to 31 December 2019.
RESULTS: During the study period, 5791 patients received plasma transfusions. The overall prevalence of single-unit plasma was 17.1% for 988 patients. The majority, 3047 (52.6%), occurred at one hospital, 2132 (36.9%) among five hospitals and 612 (10.7%) at the remaining six hospitals. Cardiac and gastrointestinal (GI)/transplant transfused 2707 (46.8%), combined respiratory, neurological, orthopaedic and congenital/dermatology/other comprised 2133 (36.9%) of the six hospitals that transfused less than 200 patients, four (66.7%) transfused single units above the overall prevalence.
CONCLUSIONS: In this hospital system, more than one in six patients received a transfusion of a single plasma unit. Six of the 12 hospitals had 89.5% of the patients who were transfused plasma. Six service lines transfused 83.7% of all patients receiving plasma. Hospitals that infrequently transfused plasma were more likely to under-dose.

In this study, it was aimed to investigate bacterial contamination in apheresis platelet suspensions (APS) by automated blood culture system and flow cytometry method (FCM).33 spiked APS each using 11 bacterial strains (5 standard strains, 6 clinical isolates), were prepared in three different dilutions (1-10, 10-50, 50-100 cfu/mL), incubated in two different temperatures (35-37 °C and 22-24 °C) and different incubation times (18-96 h) evaluated by FCM. This three different dilutions were also inoculated into special platelet culture bottles (BacT/ALERT® BPA) and loaded into the blood culture system. Additionally 80 APSs routinely prepared in the Transfusion Center were evaluated by both FCM and the blood culture system. Platelets were lysed by freeze-thaw method.All spiked samples were positive with BacT/ALERT® BPA in 12-18 h. In 96 h incubation at 22-24 °C, the presence of bacteria was detected by FCM in all other samples (31/33) except low dilutions (1-10 and 10-100 CFU/ml) of K.pneumoniae standard strain. In the 35-37 °C, the presence of bacteria was detected by FCM in all samples (33/33) after 48 h of incubation. In routine APS one sample detected as positive (Bacillus simplex) with BacT/ALERT® BPA and no positivity was detected by FCM.The freeze-thaw method, which we have optimized for the lysis of platelets, is very practical and can be easily applied. The BacT/ALERT® system has been found to be very sensitive in detecting bacterial contamination in PSs. Flow cytometry method has been found to be successful, fast, easy to use and low cost in detecting bacterial contamination in PSs.

OBJECTIVE: Blood safety measures used by blood establishments to increase blood component safety can be validated using Transfusion-Relevant Bacterial Reference Strains (TRBRS). Ultra-cold storage conditions and manual preparation of the current TRBRS may restrict their practical use. To address this issue, the ISBT Transfusion-Transmitted Infectious Diseases Working Party\'s Bacterial Subgroup organized an international study to validate TRBRS in a user-friendly, lyophilised format.
METHODS: Two bacterial strains Klebsiella pneumoniae PEI-B-P-08 and Staphylococcus aureus PEI-B-P-63 were manufactured as lyophilised material. The lyophilised bacteria were distributed to 11 different labs worldwide to assess the robustness for enumeration, identification and determination of growth kinetics in platelet concentrates (PCs).
RESULTS: Production of lyophilised TRBRS had no impact on the growth properties compared with the traditional format. The new format allows a direct low-quantity spiking of approximately 30 bacteria in PCs for transfusion-relevant experiments. In addition, the lyophilised bacteria exhibit long-term stability across a broad temperature range and can even be directly rehydrated in PCs without losing viability. Interlaboratory comparative study demonstrated the robustness of the new format as 100% of spiked PC exhibited growth.
CONCLUSIONS: Lyophilised TRBRS provide a user-friendly material for transfusion-related studies. TRBRS in the new format have improved features that may lead to a more frequent use in the quality control of transfusion-related safety measures in the future.

As the aging process accelerates, the age structure of blood donors turns to older and even aged groups. Methylmalonic acid (MMA), a byproduct of propionate metabolism, may be upregulated in the serum of older adults. As a mediator of chronic disease and tumor progression, the MMA content in blood products has become the focus of research. Absolute concentrations of MMA in blood products were determined based on the liquid chromatography-tandem mass spectrometry, so as to analyze how they were affected by donors\' age, sex, and frequency of blood donation. The MMA content in leukocyte-depleted suspended red blood cell (lds-RBC) was significantly higher than that in fresh plasma (p<0.0001). The MMA content among five age groups showed no difference in either fresh plasma or lds-RBCs. The MMA content in fresh plasma was similar in the parameters of the sex, whereas that in lds-RBCs was higher in males than that in females (p=0.035). There were no significant differences in MMA content when it comes to different frequencies of blood donors in either fresh plasma or lds-RBCs. Additionally, there was no significant difference or clear trend in the rate of elevated plasma MMA levels among different sexes, age groups, and blood donation frequency groups. MMA in the blood products from donors in China does not compromise the safety of blood transfusions for cancer patients. Nevertheless, there is a need to focus on MMA levels in Chinese and to develop race-specific and age-specific normal reference ranges.

To determine the kinetics of hepatitis E virus (HEV) in asymptomatic persons and to evaluate viral load doubling time and half-life, we retrospectively tested samples retained from 32 HEV RNA-positive asymptomatic blood donors in Germany. Close-meshed monitoring of viral load and seroconversion in intervals of ≈4 days provided more information about the kinetics of asymptomatic HEV infections. We determined that a typical median infection began with PCR-detectable viremia at 36 days and a maximum viral load of 2.0 × 104 IU/mL. Viremia doubled in 2.4 days and had a half-life of 1.6 days. HEV IgM started to rise on about day 33 and peaked on day 36; IgG started to rise on about day 32 and peaked on day 53. Although HEV IgG titers remained stable, IgM titers became undetectable in 40% of donors. Knowledge of the dynamics of HEV viremia is useful for assessing the risk for transfusion-transmitted hepatitis E.

UNASSIGNED: blood transfusion remains an essential therapeutic intervention, but the occurrence of transfusion reactions makes its administration even more complex. Vigilant reporting of such reactions by recipients of blood products is essential for effective haemovigilance. This study aimed to determine the frequency and nature of transfusion reactions.
UNASSIGNED: conducted over five years (2017-2021) at the Haemovigilance Department of the Rabat Regional Blood Transfusion Centre, this retrospective study exploited incident forms notified by health establishments and data from the regional blood transfusion centre\'s computer system.
UNASSIGNED: from 1 January 2017 and 31 December 2021, the Rabat Regional Blood Transfusion Centre distributed 435,651 labile blood products to various healthcare establishments, which reported 191 transfusion reactions involving 191 patients. The median age of the patients was 44.3 years, with an overall cumulative incidence of transfusion reactions of 0.44 per 1000 labile blood products delivered. The predominant reactions were non-haemolytic febrile and allergic reactions, accounting for 41.36% and 35.60% respectively. Grade 1 reactions accounted for 87% of all reactions recorded. During the study period, three deaths were recorded, with ABO incompatibility and transfusion-related acute lung injury (TRALI) accounting for two and one case respectively. Transfusion reactions involving erythrocyte components were significantly more frequent than those involving platelet and plasma components.
UNASSIGNED: this study revealed a relatively low incidence of transfusion reactions (0.44%), dominated by non-haemolytic febrile and allergic reactions. Several levels of failure were identified, in particular under-reporting of reactions and inadequate training in transfusion practices and haemovigilance, as well as the need for an effective electronic transfusion reaction reporting system to facilitate reporting and identification of underlying problems and risk factors to improve the quality of transfusion care provided to patients.