Vox Sanguinis最新文献

Background and objectives: Donor selection questions differentially impacting ethnic minorities can discourage donation directly or via negative word-of-mouth. We explore the differential impact of two blood safety questions relating to (i) sexual contacts linked to areas where human immunodeficiency virus (HIV) rates are high and (ii) travelling to areas where malaria is endemic. Epidemiological data are used to assess infection risk and the need for these questions.

Materials and methods: We report two studies. Study 1 is a behavioural study on negative word-of-mouth and avoiding donation among ethnic minorities (n = 981 people from National Health Service Blood and Transplant (NHSBT) and the general population: 761 were current donors). Study 2 is an epidemiology study (utilizing NHSBT/UK Health Security Agency (UKHSA) surveillance data on HIV-positive donations across the UK blood services between1996 and 2019) to assess whether the sexual risk question contributes to reducing HIV risk and whether travel deferral was more prevalent among ethnic minorities (2015-2019). Studies 1 and 2 provide complementary evidence on the behavioural impact to support policy implications.

Results: A high proportion of people from ethnic minorities were discouraged from donating and expressed negative word-of-mouth. This was mediated by perceived racial discrimination within the UK National Health Service. The number of donors with HIV who the sexual contact question could have deferred was low, with between 8% and 9.3% of people from ethnic minorities deferred on travel compared with 1.7% of White people.

Conclusion: Blood services need to consider ways to minimize negative word-of-mouth, remove questions that are no longer justified on evidence and provide justification for those that remain.

Background and objectives: Transfusions are common, but their use is decreasing in some countries as a result of increased risk awareness and the implementation of patient blood management (PBM), an evidence-based approach to optimize patient outcomes. This study aimed to detail the implementation of PBM in a Brazilian state and its impact on transfusion rates and associated costs.

Materials and methods: The PBM implementation involved several strategies: medical education, haematology consultation services, provision of intravenous iron and other medications, establishment of PBM and perioperative anaemia clinics, cell salvage and acute normovolaemic haemodilution, anaemia reference laboratories and rotational thromboelastometry. The program's implementation was assessed through quality indicators and cost analysis.

Results: Since 2016, there have been reductions in transfusion rates, mainly in red blood cell (RBC) transfusion. Quality indicators showed an increase in single-RBC transfusions from 53% in December 2015 to 85.9% in June 2024 and a decrease in transfusions for patients with Hb ≥7 g/dL from 5.9% in March 2021 to 2.7% in May 2024. The PBM programme led to an estimated annual cost saving of R$2.63 million (US $487,000), if considered RBC direct costs, and from R$9.69 million to R$16.145 million (US $1.79-$2.99 million) in activity-based costs, considering only the reduction in RBC transfusions.

Conclusion: The PBM programme in Ceará successfully reduced transfusion rates and associated costs through a multidisciplinary approach, medical education and government support. This model demonstrates the potential for significant healthcare improvements and cost savings and can serve as a benchmark for other regions and countries, especially in low- and middle-income settings.

Background and objectives: In July 2019, Australia removed the upper age limit for returning donors (previously 80 years) and increased the upper age for new donors from 70 to 75 years. This study assessed the safety of our new policy for our newly eligible upper age donors (NEUADs).

Materials and methods: For the period, 14 July 2019 to 30 June 2023, the relative risk (RR) of individual adverse events in NEUADs was compared with younger cohorts.

Results: There were 4529 NEUADs who made 8000 donations. The overall rates of vasovagal reactions (VVRs) were significantly lower in the NEUAD cohort. However, compared with younger donors; returning NEUADs had a significantly higher rate of loss of consciousness (RR 2.62; 95% confidence interval [CI]: 1.41-4.86) and new NEUADs had a significantly higher rate of offsite VVRs (RR 1.60; 95% CI: 1.08-2.37). Both new and returning NEUADs had significantly higher rates of VVR requiring outside medical care (RR 2.48; 95% CI: 1.28-4.79 and RR 4.45; 95% CI: 2.00-9.91 respectively).

Conclusion: Our findings support historical findings that overall VVR rates decline with age but suggest a higher risk of more serious VVRs.

Background and objectives: Leucoreduction is used to remove donor leucocytes during red blood cell (RBC) manufacture. However, not all are removed, and long-term survival of donor leucocytes, termed transfusion-associated microchimerism (TAM), has been shown to occur in some patients following RBC transfusion. The mechanism of TAM occurrence is unknown. One hypothesis is that viable donor haematopoietic cells remain within RBC units that could engraft. However, the analysis of cells remaining within leucoreduced RBC units has been minimal. This study aimed to isolate and analyse any residual leucocytes recovered from leucoreduced RBC units.

Materials and methods: Leucoreduced RBC units were analysed on Day 1 (n = 4) and Day 42 (n = 4) post collection. Residual leucocytes were isolated using the EasySep™ RBC Depletion Reagent. Cell type analysis was conducted by flow cytometry using a leucocount reagent, a viability marker (7-amino-actinomycin D [7AAD]) and specific antibodies to CD45 and CD34. A representative 'pre-filter' sample was also obtained at the time of whole-blood donation to ensure expected cell counts across the donor samples.

Results: Analysis of the pre-filter sample showed that CD45+/CD34+ cells accounted for 0.02%-0.07% of all leucocytes. Up to 253,850 residual leucocytes were isolated across both storage timepoints, and of these, up to 48 cells were CD45+/CD34+/7AAD-.

Conclusion: Viable CD45+/CD34+ cells were isolated from leucoreduced RBC units, indicating the potential for donor progenitor cells to be present during transfusion. Further characterization of these residual cells is required to explain how TAM may occur in some patients following RBC transfusion.

Background and objectives: Canadian Blood Services defers donors during and for 4 months after oral pre-exposure or post-exposure prophylaxis (PrEP/PEP) for human immunodeficiency virus (HIV) because of concerns about altered viral kinetics. We assessed the impact of the switch from a time-based deferral for men who have sex with men (MSM) to sexual risk behaviour criteria on PrEP/PEP deferrals.

Materials and methods: Data on PrEP/PEP deferral codes were extracted from our National Epidemiology Database for the 22 months before (Period 1) and after (Period 2) the criteria change.

Results: PEP deferrals remained stable (2.3 vs. 1.7 per 100,000 donations in Periods 1 and 2, p = 0.2892), about 45% and 33%, respectively, of these donors who reported a recent needle stick injury. PrEP deferrals increased from 5.9 to 12.4 per 100,000 (p = 0.0001); approximately 30% of donors in both periods had other HIV risk factor deferrals. Donors deferred for PrEP use alone were more likely to be male, first-time users and younger than other donors.

Conclusion: The switch to sexual risk behaviour led to a small increase in deferrals for PrEP. We may not be measuring the full impact of deferral criteria because potential donors may self-defer and PrEP use is increasing.

Background and objectives: In the setting of tissue hypoxia, S-nitrosylated haemoglobin (SNO-Hb) plays crucial roles in the control of blood flow. This is associated with decreased oxygen affinity to haemoglobin and increase in tissue oxygenation. Red blood cell (RBC) transfusion is primarily performed to improve tissue oxygenation in anaemic patients. RBCs after storage undergo a variety of biochemical and functional alterations, including deficiency of nitric oxide (NO) bioactivity. However, how donor characteristics affect NO levels during RBC storage is unclear. We sought to investigate the association of blood donor age, gender and storage duration with NO and SNO-Hb levels in blood units.

Materials and methods: Blood samples from 42 healthy younger (≤30 years) and older (≥45 years) donors were collected and stored for up to 42 days. Total NO kits were used to detect total nitrite and nitrate levels in blood storage solution. SNO-Hb levels in RBCs were detected and analysed by quantitative mass spectrometry.

Results: Total NO levels in the blood storage solution significantly increased with donor age and storage duration. Proteomic analysis revealed that RBCs from older donors, particularly older females, significantly lost SNO-Hb during storage. Our findings indicate that RBCs from older donors are associated with reduced SNO-Hb levels and increased NO metabolites in storage solution after ≥35 days storage.

Conclusion: The findings suggest stored RBCs from older donors may have reduced capacity to deliver oxygen to tissues under hypoxia. A shorter shelf life may be required for storing RBCs from older donors, particularly older females.

Background and objectives: Anaemia is a treatable common condition with various aetiologies and is prevalent in hospitalized patients. However, anaemia is inconsistently worked up and treated in the inpatient setting, in part because there is no standardized inpatient diagnostic and treatment approach to anaemia. Therefore, the objective of this study was to examine the diagnostic approach and prevalence of common aetiologies of anaemia in hospitalized patients and test for an association between aetiologies of anaemia and patient characteristics.

Materials and methods: This study is a prospective observational study of hospitalized adult patients with anaemia. Patient laboratory data were used to assess the frequency of anaemia diagnostic workup and common aetiologies of anaemia.

Results: In a sample of 945 patients (mean age 58 years, 57% female and 72% Black), 30% patients had chronic anaemia, 11% had multifactorial anaemia, 5% had iron deficiency and 37% had insufficient laboratory data to determine their anaemia aetiology (unidentified aetiology). Patients with an unidentified aetiology received fewer transfusions and were more likely to be White, have longer hospital stays and have higher nadir haemoglobin levels.

Conclusion: A significant portion of hospitalized patients with anaemia did not have an identified aetiology. A standardized diagnostic algorithm could decrease this number and help patients receive appropriate treatment.

Background and objectives: In the setting of trauma and suspected critical bleeding, indications to commence blood transfusions remain unclear, with high rates of potentially avoidable transfusions. Prehospital blood lactate measurements could help predict the need for blood transfusions. The aim of this study was to compare measurements detected by a point-of-care (POC) lactate device with laboratory measured lactate levels.

Materials and methods: This was a cross-sectional study conducted in the emergency department. Eligible patients were those with suspected major trauma and critical bleeding. Venous or arterial blood samples were collected. POC measurements of lactate levels were conducted using a StatStrip Xpress® lactate meter and compared with laboratory values.

Results: Among 70 patients, the mean difference between the POC and laboratory lactate results was -0.19 mmol/L, with limits of agreement at -1.9 and 1.5. Most measurements (n = 66; 94.3%) were within the limits of agreement. A POC lactate level of >3.3 mmol/L had >90% specificity for transfusion, whereas a level <1.4 mmol/L had 90% sensitivity to rule out a transfusion.

Conclusion: The level of agreement of POC lactate with the laboratory lactate was high. Research on clinical decision rules for pre-hospital transfusion that incorporate POC lactate measures is therefore feasible.