Vox Sanguinis最新文献

Background and objectives: The available information on blood groups in the Chilean population is derived from studies on aboriginal cohorts and routine serological test results. The purpose of this study is to conduct a comprehensive analysis of genotypes, phenotypes and blood group alleles in donors from northern, central and southern Chile using molecular methods.

Materials and methods: Overall, 850 samples from donors in northern, central and southern Chile were genotyped. Allelic, genotypic and antigenic frequencies were calculated and compared among regions. Of these, 602 samples were analysed by haemagglutination, and discrepancies found between phenotypes and genotypes were investigated. The immunogenic potential of antigens was calculated by the Giblett equation, using the antigenic frequencies of donors from Santiago and the alloantibody frequencies of patients from the same region.

Results: Alleles of low prevalence, variant alleles and those responsible for the absence of high-prevalence antigens were found. Significant differences were observed between the antigenic frequencies of the three regions. Discrepancies between serologic and molecular results were mostly attributed to the molecular background affecting antigen expression. In the calculation of the immunogenic potential of antigens, the highest value was attributed to the Di^a antigen.

Conclusion: These findings represent the first molecular characterization of blood group antigens in Chileans. Our results highlight the necessity of using molecular tools to explore the genotypes underlying variant phenotypes, low-frequency antigens and antigens lacking specific antisera that cannot be detected by haemagglutination. Additionally, they emphasize the importance of understanding the distribution of blood groups among different populations.

Background and objectives: Homophily represents the extent to which people feel others are like them and encourages the uptake of activities they feel people like them do. Currently, there are no data on blood donor homophily with respect to (i) people's representation of the average prototypical UK blood donor and (ii) the degree of homophily with this prototype for current donors, non-donors, groups blood services wish to encourage (ethnic minorities), those who are now eligible following policy changes (e.g., men-who-have-sex-with-men: MSM) and recipients. We aim to fill these gaps in knowledge.

Materials and methods: We surveyed the UK general population MSM, long-term blood recipients, current donors, non-donors and ethnic minorities (n = 785) to assess perceptions of the prototypical donor in terms of ethnicity, age, gender, social class, educational level and political ideology. Homophily was indexed with respect to age, gender and ethnicity.

Results: The prototypical UK blood donor is perceived as White, middle-aged, middle-class, college-level educated and left-wing. Current donors and MSM are more homophilous with this prototype, whereas recipients and ethnic minorities have the lowest homophily. Higher levels of homophily are associated with an increased likelihood of committing to donate.

Conclusion: The prototype of the UK donor defined this as a White activity. This, in part, may explain why ethnic minorities are less likely to be donors. As well as traditional recruitment strategies, blood services need to consider broader structural changes such as the ethnic diversity of staff and co-designing donor spaces with local communities.

Background and objectives: Implementation of national haemovigilance programmes has significantly improved donor and recipient safety. Recently, India completed a decade of successful implementation of its national haemovigilance programmes. The national programme is still enrolling more blood centres. This study aimed to highlight the strengths and weaknesses of Haemovigilance Programme of India (HvPI), thereby providing valuable insights for future initiatives.

Materials and methods: The National Coordinating Centre (NCC) conducted a multi-centre, cross-sectional questionnaire-based survey among the reporting blood centres (January to April 2022). The survey consisted of three sections with a total of 27 questions focusing on the demographics of the participant blood centre as well as the impact on the recipient and donor haemovigilance. The survey was sent to 733 blood centres regularly reporting to the donor and recipient HvPI through Donor and Hemovigil Software.

Results: Total 296 responses were received (response rate of 40.4%) with maximum participation of private non-teaching hospital-based blood centres (33.8%). After their involvement in recipient HvPI, 85.7% of the respondents reported changes in their blood centre's work procedures, with the maximum improvement seen in the documentation of transfusion reactions (92.7%). Out of the 278 respondents who participated in donor HvPI, 89.9% (250) found that their blood centre's policies or work process changed as a result of their involvement in the programme.

Conclusion: In conclusion, our haemovigilance programme facilitates national collaboration for learning and sharing experiences, leading to improved policies and practices in reducing adverse reactions for both recipients and donors.

Background and objectives: Human platelet antigens (HPA) play a central role in foetal and neonatal alloimmune thrombocytopenia (FNAIT), post-transfusion purpura and some cases of platelet therapy refractoriness. The frequency distribution of HPA had not been studied in the Greek population before we started to create a registry of HPA-typed apheresis platelet donors. The aim of this study was the determination of the frequency of various HPA in the Greek population, through the establishment of a registry of typed donors.

Materials and methods: Here, we report on the first 1000 platelet donors of Greek origin who gave informed consent and were genotyped for 12 pairs of antithetical HPA by Single Specific Primer-Polymerase Chain Reaction (SSP-PCR), including HPA-1, HPA-3, HPA-5 and HPA-15. Antigen frequencies are reported, and allele frequencies were calculated and compared with other European and non-European populations. Tested donors cover all ABO and Rhesus D antigen spectrum.

Results: Antigen and allele frequencies are very similar to other White populations. The frequency of HPA-1bb is 2.9% in our study, and the frequency of HPA-2b, HPA-4b, HPA-9b and HPA-15b is also slightly higher than in other literature reports, while the frequency of HPA-15b was found higher than that of HPA-15a.

Conclusion: We report antigen and allele frequencies for a large array of clinically significant HPA for the first time in the Greek population. Frequencies are consistent with other European populations. This registry of HPA-typed platelet donors, available to donate on demand, is an important asset for the treatment of FNAIT cases in Greece.

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.