Vox Sanguinis最新文献

Background and objectives: The para-Bombay phenotype is characterized by the lack of ABH antigens on red blood cells, but ABH substances can be found in saliva. In this study, we report a novel FUT1 allele responsible for a para-Bombay phenotype in a pregnant woman.

Materials and methods: ABO, H and Lewis phenotypes and the secretor status were studied in blood and saliva samples. ABO, FUT1 and FUT2 genes were sequenced. Haplotypes were determined by clone sequencing. The structural impact of the new FUT1 variant was assessed using ChimeraX and AlphaFold software.

Results: Serological tests revealed a para-Bombay phenotype. Sequencing studies suggested the presence of the ABO*A1.01 and ABO*O.01.01 reference alleles. The molecular analysis of FUT1 revealed the presence of the FUT1*01W.31 allele and the novel c.521T>C variant responsible for the p.Phe174Ser change. FUT2 study showed the homozygous substitution c.390C>T. The analysis of the AlphaFold model of α2FucT1 predicted that Phe174 is a structural residue located deep inside the protein's hydrophobic core.

Conclusion: We identified the FUT1*01W.31 allele in compound heterozygosity with a novel allele carrying the missense substitution c.521T>C as responsible for the para-Bombay phenotype. In silico studies support that the p.Phe174Ser gives rise to a weak FUT1 variant.

Background and objectives: On-site donor deferral for low haemoglobin (Hb) levels poses significant challenges for blood establishments globally, leading to material wastage and consumption of valuable staff and donor time. Traditionally, donors are deferred based on a single visit's Hb measurement, without considering previous Hb levels and measurement variability. This study aims to quantify, in different settings, the potential impact of an alternative deferral algorithm based on historical mean Hb levels.

Materials and methods: We retrospectively reassessed donor eligibility in 20,430,816 donations and deferrals in Australia, Belgium, Finland, France, the Netherlands, South Africa and the United States using an algorithm that considers a repeat donor eligible as long as their historical mean Hb is above the deferral threshold and deviations from the mean are consistent with anticipated measurement variability. We quantified the potential impact of the alternative algorithm by calculating the change in donations and deferrals.

Results: Across countries, the alternative algorithm may reduce low Hb deferrals between 30% and 70%. Additionally, in every country, a small proportion of current donors (~1%) donate who exhibit consistent low Hb levels. Balancing new deferrals and donations, the estimated net increase in donations across countries ranges between 0.7% and 3.3%.

Conclusion: The alternative deferral algorithm based on mean Hb levels is a first step towards a more comprehensive assessment of Hb levels to determine donor eligibility. Further research is needed to refine the algorithm, to determine its long-term impact, to improve the model with information related to iron stores and recovery and to address the impact on donor safety.

Background and objectives: Suboptimal use of RhD-negative red blood cells (RBCs) can lead to reduced inventories of this scarce resource. Prevention of D-alloimmunization is particularly important for RhD-negative females of childbearing potential (FCPs). The utilization of RBCs in the Region of Southern Denmark was analysed to elucidate opportunities for conserving RhD-negative RBCs.

Materials and methods: RBC transfusions from 1 January 2020 to 31 December 2024 were identified using the South Danish Transfusion Service's laboratory and inventory IT systems. RhD-typing results, including the time when the patient's RhD type became known, were used to identify whether a historical or current RhD type was available at the time of RBC transfusion. Transfusions were grouped into 72-h 'transfusion episodes', and the achievement of the RBC critical administration threshold (CAT; 3 RBC units/h) was noted.

Results: There were 30,564 recipients of 162,778 RBC units. Of these units, 36,483 (22%) units were RhD-negative, out of which 22,922 (63%) were crossmatched (i.e., sufficient time was available to demonstrate compatibility with recipient plasma) and issued to RhD-negative non-FCPs; 1934 (5%) units were uncrossmatched and urgently transfused to 1409 patients who were historically known to be RhD-positive, and 934 (3%) units were transfused to 303 non-FCPs without a current or historical RhD type. In RhD-negative patients who reached CAT, 1440 of 36,483 (4%) RhD-negative RBC units were transfused after they had reached CAT.

Conclusion: Many of the RhD-negative RBC units were issued to recipients who were not RhD-negative FCPs, those known to be RhD-positive and those requiring massive transfusion, suggesting strategies for resource conservation.

Background and objectives: The role of viscoelastic haemostatic assays (VHAs) versus conventional coagulation tests (CCTs) in chronic liver disease (CLD) in the emergency department (ED) is undefined. We aimed to characterize VHA profiles and concordance with CCT.

Materials and methods: Patients with CLD presenting to EDs (January 2016-August 2023) were included. Post-transfusion results were excluded. VHA was categorized as hypo/normo/hypercoagulable using manufacturer ranges. CCT-coagulopathy was defined as international normalized ratio (INR) >1.5, platelets <50 × 10⁹/L or fibrinogen <1.0 g/L.

Results: VHA use increased over time (incidence rate ratio [IRR] 1.23, 95% confidence interval [CI]: 1.19-1.28; p < 0.001). Of 438 patients, 397 underwent rotational thromboelastometry (ROTEM) and 41 thromboelastography (TEG). ROTEM showed hypocoagulability in 275 patients (69%), normocoagulability in 84 (21%), hypercoagulability in 18 (5%) and mixed profiles in 14 (4%). Deficits were fibrinogen deficiency in 220 patients (55%), factor deficiency in 148 (37%), hyperfibrinolysis in 42 (11%) and platelet deficiency in 33 (8%). TEG showed hypocoagulability in 22 (54%), normocoagulability in 13 (32%), hypercoagulability in 3 (7%) and mixed profiles in 3 (7%). Deficits included fibrinogen deficiency in 19 patients (46%), factor deficiency in 6 (15%), hyperfibrinolysis in 5 (12%) and platelet deficiency in 3 (7%). In 120 VHA-CCT paired results, fibrinogen deficiency was detected by both in 18%, VHA alone 26%, CCT alone 2%; platelet deficiency by both 5%, VHA alone 5%, CCT alone 5%; factor deficiency by both 22%, VHA alone 3% and CCT alone 42%.

Conclusion: Hypocoagulability from reduced fibrin-based clot strength was predominant. Marked discordance between VHA and CCT was observed in coagulation factor deficiency. CLD-specific thresholds are required to guide transfusion.

In 2025, the Parasitology Subgroup of the International Society of Blood Transfusion (ISBT) Transfusion-Transmitted Infectious Diseases (TTID) Working Party (WP) transitioned into the Emerging Pathogens and Parasitology (EPP) Subgroup (referred to here as the EPP). This followed recognition that the parasitology subgroup's relevance was limited in scope given the small number of transfusion-transmissible parasites that still lacked effective mitigation. The EPP was proposed to address themes that are not adequately covered by existent subgroups of the TTID WP. In addition to maintaining a focus on transfusion-transmissible parasitic infections, a major objective of the EPP is horizon scanning for emerging pathogens. Horizon scanning refers to a systematic and proactive approach of information gathering and evaluation to identify early-and often subtle-signals of possible threats, which in this case pertain to blood safety. The EPP will characterize those risks to guide decision making and preparedness, pertaining to the safety and sufficiency of the blood supply. We describe the scope, structure and functioning of the EPP, within the broader TTID WP. We include examples of projects that may be pursued and outputs from horizon scanning a contemporary emerging pathogen. This collectively highlights the strategic relevance and objectives of the EPP.

Background and objectives: Tranexamic acid (TXA) as an adjunct to prophylactic platelet transfusion is sometimes used to prevent bleeding in patients with malignancies experiencing chemotherapy-induced thrombocytopenia. However, there is little biological evidence in support. This pilot exploratory study aimed to evaluate the haemostatic efficacy of TXA before and after platelet transfusion versus platelet transfusion alone in patients with haematological malignancies experiencing chemotherapy-induced thrombocytopenia.

Materials and methods: Rotational thromboelastometry (ROTEM; EXTEM, tissue plasminogen activator [tPA]-EXTEM and FIBTEM) was used to assess the haemostatic effect of these treatments.

Results: Eighteen patients were randomized to receive platelet transfusion and either 3 or 1.5 g of TXA per day or to be observed. At enrolment, ROTEM parameters were similar across groups. TXA alone did not affect EXTEM clot formation time (CFT) or maximum clot firmness (MCF). A trend towards increased EXTEM CFT and MCF values 2 h after platelet transfusion was observed. The effect of TXA was witnessed by the increase in tPA-EXTEM lysis index at 60 min (LI60). In the observation group, tPA-EXTEM LI60 also significantly increased after platelet transfusion. The World Health Organization (WHO) rates for grade ≥2 bleeding and the median number of platelet transfusions were similar across all groups.

Conclusion: Platelet transfusion as well as TXA decreased fibrinolysis for this patient population. This could be explained by the plasminogen activator inhibitor 1 contained in platelets. Future research should explore other alternative treatments and the utility of viscoelastometric testing to guide platelet transfusions, particularly in cases of bleeding or platelet transfusion refractoriness.

Background and objectives: The US Interorganizational Task Force for Domestic Disasters and Acts of Terrorism (Interorganizational Disaster Task Force [IDTF]) is coordinated by the Association for the Advancement of Blood & Biotherapies (AABB). The IDTF was founded in 2001 in response to the 9/11 attack and is part of the US Department of Homeland Security's National Response Framework for disaster responses. We sought to set out the objectives, methods and activities of the IDTF.

Materials and methods: We reviewed the organization and history of the IDTF and representative disaster responses coordinated by the IDTF.

Results: The IDTF is composed of representatives from five civilian and military blood organizations, five key healthcare organizations and liaisons from the US Department of Health and Human Services (HHS) and two HHS agencies. The IDTF promotes disaster preparation by blood centres and transfusion services and communicates weekly with its federal partners on the disaster readiness of the US blood supply. During disasters, which often interrupt regional donor operations, the IDTF helps in guiding national blood collection efforts, provides data-based messages to HHS and the public on blood donation needs and coordinates inter-regional blood transport and blood-supply infrastructure support. The IDTF has been activated for large-scale weather events, Zika and COVID-19 epidemics, cyberattacks and an earthquake (Haiti).

Conclusion: Because the US blood supply is not under a centralized authority, the IDTF is a unique and critical forum for collaborative private-public sector partnership to overcome disaster-related challenges to blood availability.

Background and objectives: The Nordic region includes Denmark, Finland, Iceland, Norway and Sweden, with a population of >27.5 million. Blood services are managed differently in each country. Current data on platelet concentrate (PC) production methods and capacity are important for developing efficiency and cross-border preparedness.

Materials and methods: Retrospective data for 2018-2022 were collected through an online survey sent to all blood centres producing platelets in the region. Questions focused on collection procedures (aphaeresis [AP] or whole blood [WB]-derived pools), use of bacterial culture screening (BCS) or pathogen reduction (PR), shelf-life, transfusion practices and quality control.

Results: A total of 43 blood centres provided data (83% response), including complete national coverage for Sweden, Finland and Iceland. Between 2018 and 2022, 632,596 PCs were produced at participating centres. Annual PC production was stable over the period. Most PCs were WB pools (77%). Automated separation to produce interim platelet unit (IPU) pools was performed at 19 centres. PR and BCS were used in 17 and 23 centres, respectively. Shelf-life ranged from 5 days (no safety measure) to 7 days (PR or BCS). The number of PCs transfused in the region declined by ~5% from 2018 to 2022.

Conclusion: Platelet production methods, including safety measures to prevent bacterial contamination, varied widely in the Nordic region. Harmonization, including the use of PR or BCS with 7-day storage, may contribute to resilient platelet supplies in the region.

Background and objectives: Two prior publications have identified a novel RHD variant in the Australian population with the pattern of single nucleotide variation (SNV) c.186G>T, c.410C>T, c.455A>C, c.602C>G, c.604G>A, c.733G>C, and a deletion or rearrangement with RHCE exon 9. The Australian Red Cross Lifeblood provides testing across Australia, and over a period of 8 years, this same RHD variant has been noted, with some cases presenting with allogeneic anti-D.

Materials and methods: Cases with the combination of SNVs were identified with the RHD BeadChip™ panel and massively parallel sequencing, and were collated. Clinical presentation, phenotype and the specificity of any antibodies were also reviewed.

Results: Twelve cases of the same pattern of SNV and exon change were identified. There was consistent finding of c.186G>T, c.410C>T, c.455A>C, c.602C>G, c.604G>A and c.733G>C, in association with RHCE replacement of exon 9. All cases except one were phenotypically D-positive. Nine of 12 cases presented with anti-D antibodies, often associated with pregnancy. Where ethnicity was reported, all individuals were of Australian Indigenous ethnicity.

Conclusion: This RHD variant is observed to date only in people of Australian Indigenous ethnicity and has clinical relevance. With wider knowledge of the variant, it is anticipated that there will be increased screening in this population, especially in women of childbearing age.