Vox Sanguinis最新文献

Background and objectives: Plasma transfusion is indicated for patients with coagulopathy and active bleeding or those undergoing major surgery. Appropriate use is defined by an international normalized ratio (INR) >1.7 and a dose of 3-4 units for adults. However, audits in tertiary care settings consistently revealed high rates of inappropriate plasma use. At Niagara Health, audits across three community hospitals showed that 42% of plasma transfusions in hospitalized adults were inappropriate, largely due to limited understanding of proper indications. This misuse leads to resource wastage, higher costs and unnecessary patient exposure to transfusion-related risks. The aim of this project was to improve appropriate plasma transfusion rates among hospitalized adults in three Niagara region hospitals by 25% over a 12-month period.

Materials and methods: This non-randomized, interrupted time series quality improvement project followed the Model for Improvement (MFI) framework. Sequential Plan-Do-Study-Act cycles began in July 2024, with monthly monitoring of transfusion rates. Interventions included an awareness campaign, enhanced audit and feedback and implementation of an electronic transfusion order set in the electronic medical record (EMR).

Results: During the study, 253 plasma units were transfused. Median monthly appropriateness rates were 90% (INR >1.7), 89% (dose >2 units) and 78% (both criteria). Appropriateness improved, particularly in dosing. Out-of-guideline requests screened by technologists decreased by 15%, with no significant change in plasma or red cell use.

Conclusion: Electronic order sets, technologist screening, education and audit-feedback improved adherence to plasma transfusion guidelines without increasing workload or affecting other blood product use. These strategies may be scalable to other components.

Background and objectives: Dengue can cause mild or no symptoms, meaning infected individuals can donate blood during the viraemic phase. Although transfusion transmission is rare, globally many blood operators restrict or test donors returning from dengue transmission areas before donating in non-endemic regions. While Australia does not have endemic dengue, it has receptive areas with established competent mosquitoes, and local transmission has occurred. We assessed the residual risk to transfusion safety posed by travellers from outbreak-affected receptive areas to other areas of Australia to inform evidence-based blood safety policies.

Materials and methods: Dengue outbreaks were identified using National Notifiable Disease Surveillance System data, spatial classification, outbreak thresholds and literature-based parameters. We used the European Up-Front Risk Assessment Tool alongside national surveillance and population data to model transfusion risk at national and sub-national levels during significant local outbreak periods in Australia.

Results: The estimated risk of severe outcomes from dengue-infected blood components was extremely low-between 1 in 13.4 billion and 1 in 1.34 trillion at the national level. The risk differed regionally but still had only a negligible absolute impact.

Conclusion: The residual risk of transfusion-transmitted dengue from travellers returning from outbreaks in Australia to non-receptive regions is extremely low. These findings support that additional travel questions, restrictions or testing are unnecessary beyond the outbreak areas. This study provides a robust, evidence-based framework for geographically targeted, risk-based policies and concludes that additional restrictions outside the outbreak areas are not required to maintain negligible blood safety risk in Australia.

Background and objectives: Vasovagal reactions (VVRs) are common adverse events associated with blood donation. While previous research has focused on intrinsic donor-related risk factors, we previously identified an association between specific meteorological elements and VVR incidence. This study aims to build on our earlier findings by investigating the potential modifying effects of collection setting and donation type.

Study design and methods: This study analysed VVR incidence data from blood donations collected in northern Nara Prefecture, Japan, over a 3-year period (April 2020-March 2023). Daily VVR incidence rates were calculated and analysed in relation to meteorological elements, including temperature, humidity, atmospheric pressure and other related factors. Comparisons across quartiles of meteorological values were performed using Kruskal-Wallis and Jonckheere-Terpstra tests. Subgroup analyses were conducted by collection setting and donation type.

Results: In mobile collections (whole blood only), significant associations were found only with the 7-day weighted moving average (7d WMA) of temperature and precipitation. In fixed-site collections, several temperature-related elements were significantly associated with VVR incidence in both same-day and 7d WMA analyses. Further stratification showed that whole blood donations at fixed sites showed limited associations with meteorological elements, whereas apheresis donations showed significant relationships with multiple temperature-related parameters in both same-day and 7d WMA analyses.

Conclusion: Meteorological elements affecting VVR incidence vary by the collection setting and donation type. Apheresis donations appear to be susceptible to environmental influences, especially ambient temperature. These findings highlight the importance of incorporating meteorological considerations into donor safety measures and operational planning, particularly for apheresis collections.

Background and objectives: Ageing populations in high-income countries reduce the proportion of potential blood donors while increasing transfusion demand. Sustaining an adequate blood supply requires higher donor motivation among younger age groups. We analysed long-term trends in whole blood donations (WBDs) in one German federal state as an indicator for challenges that may arise in other high-income countries.

Materials and methods: In our prospective longitudinal study (starting 2005), we obtained the age and sex of the donors of all WBDs in the German federal state Mecklenburg-Western Pomerania in 2019 and 2020 and compared them with the data from 2005 to 2015. Population data from the German statistical office were used to predict future WBD in two models, population-based and population-based with behaviour-adjusted prediction.

Results: WBD decreased from 118,419 in 2005 to 83,871 in 2019 (-29.2%) and 76,912 in 2020 (-35.1%). Donation rates per 1000 inhabitants declined by 19.1% between 2005 and 2019, indicating a loss of donor motivation beyond demographic effects. Based on the donation numbers of 2019, we predict a further decline of WBD in 2030 by -12.7% (population-based projection) or -15.1% (behaviour-adjusted projection), respectively.

Conclusion: The decline in blood donations is no longer solely driven by demographic changes but also by reduced motivation among younger donors. As ageing populations and changing donor behaviour are common to many high-income countries, these findings likely reflect an emerging international trend. Targeted strategies to recruit and retain young donors are urgently needed to ensure sustainable blood supplies in ageing societies.

Background and objectives: Clinically significant alloantibodies complicate transfusion and prenatal care, especially in individuals with genetic variants affecting high-frequency antigens. Many patients from African descent carry RHCE*ceVS alleles, which alter the expression of c (RH4), e (RH5) and hr^B (RH31). However, the risk and clinical impact of alloimmunization remain uncertain. We evaluated the alloimmunization in a cohort of patients with a RHCE*ceVS genotype.

Materials and methods: We conducted a retrospective study on 48 patients with a RHCE*ceVS genotype divided into three categories: prenatal care, patients with sickle cell disease (SCD) and other or unspecified diagnosis.

Results: No anti-c, anti-e or anti-hr^B were found in prenatal care patients or in patients with other or unspecified diagnosis. Among transfused patients with SCD, 50% developed an anti-e. Anti-hr^B was identified in two patients, both with SCD. Warm autoantibodies were found in 58% of transfused patients with SCD, many of whom had an anti-e.

Conclusion: The risk of developing anti-e or anti-hr^B antibodies was low in patients with an RHCE*ceVS genotype, except in those with SCD. In patients with SCD, the presence of autoantibodies, recent transfusions and technical caveats complicate the assessment of clinical impact; therefore, an individualized evaluation of alloimmunization risk is recommended.

Background and objectives: Vasovagal reactions (VVRs) are the common donor adverse reaction, especially in young and first-time donors, affecting donor return. Despite evidence-based physiological and psychological mitigation strategies (MSs), their awareness and implementation remain variable. This study aimed to assess the awareness and practice of VVR MSs across licensed blood centres in India.

Materials and methods: A cross-sectional online survey was conducted between January and March 2025. A pre-validated questionnaire was distributed via a Google Form link. Data included demographic details of respondents, centre type, annual collection and voluntary donors. It was also focused on awareness, types and usage of VVR MSs. Data were analysed using descriptive statistics, and associations were tested using χ² and logistic regression. This survey was reported in accordance with the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) guidelines.

Results: Of 4153 blood centres, 439 were included in the final analysis, having fulfilled the inclusion criteria. Among them, 370/439 (84.3%) were aware of VVR MSs, while only 298/439 (67.9%) implemented them. Water/fluid ingestion was the most common physiological strategy (254/268, 94.8%), followed by applied muscle tension (110/268, 41.1%). Among psychological strategies, primarily audiovisual distraction combined with psychosocial support was reported by 143/210 (68.1%) centres. Of the 298 centres, 213 (71.5%) offered special attention to high-risk donors, 205 (68.8%) focused on delayed VVR prevention and 132 (44.3%) had dedicated counsellors.

Conclusion: Despite good awareness, implementation of VVR MSs in Indian blood centres remains inconsistent. Nationwide policy, awareness programmes and structured training could promote uniform, evidence-based donor care and improve donor safety and retention.

Background and objectives: High concentration of human platelet antigen-1a (HPA-1a) antibodies is reported to be associated with severe foetal and neonatal alloimmune thrombocytopaenia (FNAIT). The gold standard for quantification of anti-HPA-1a antibodies is the monoclonal antibody immobilization of platelet antigen (MAIPA) assay, which is a laborious method performed in only a few reference laboratories. The aim of this study was to evaluate the performance of the commercially available bead-based Luminex assay PakLx (Immucor) for quantitative measurement of anti-HPA-1a antibodies.

Materials and methods: We analysed anti-HPA-1a antibody levels in plasma samples from 42 HPA-1a-negative women who had given birth to a child with thrombocytopaenia. Quantification of antibodies was performed with two different techniques: MAIPA analysed by spectrophotometry with results expressed in international units (IU)/mL, and PakLx analysed in the Luminex assay with results expressed as the mean fluorescence intensity (MFI).

Results: In the comparison of the two methods' ability to stratify a result as either positive or negative, PakLx demonstrated 97.6% agreement with the MAIPA assay, with positive and negative predictive values of 96.7% and 100%, respectively. The correlation of the MFI values from PakLx with IU/mL in MAIPA assay was high, with a correlation coefficient (R²) of 0.92. MFI values were converted into semi-quantitative results: high, intermediate and low levels of anti-HPA-1a.

Conclusion: PakLx shows high agreement with the MAIPA assay and allows fast laboratory turnaround time for the determination of anti-HPA-1a antibody levels. The result may be of predictive value in clinical assessments.

Background and objectives: The International Society of Blood Transfusion (ISBT) Working Party (WP) on Red Cell Immunogenetics and Blood Group Terminology (RCI&BGT) held six business meetings between December 2021 and June 2024. This report describes the new blood group systems and antigens ratified during these meetings.

Materials and methods: Candidate systems and antigens were reviewed according to serological, genetic and biological evidence. This evidence was matched against defined criteria, and the acknowledged systems/antigens were assigned a unique identifier.

Results: Four new systems, ER (ISBT 044), CD36 (ISBT 045), ATP11C (ISBT 046) and MAL (ISBT 047), were ratified. CD36 and ATP11C were de novo entries, while ER and MAL systems resolved the genetic basis for the Er and AnWj antigens. Thirteen antigens were added to existing systems: one each to LU (005), YT (011), SC (013), LW (016), KN (022), GLOB (028); an antithetical pair to KEL (006); two antigens to RHAG (030); and three to CTL2 (039). Two CTL2 antigens defined the hitherto unresolved antithetical antigens, Cs^a/Cs^b, whose genetic basis coincides with those of variants responsible for the HNA-3a/3b neutrophil antigens, respectively.

Conclusion: As of June 2024, the ISBT has acknowledged 47 blood group systems, comprising 366 antigens. The WP continues to ratify new systems and antigens, which are available on the ISBT website (http://www.isbtweb.org/working-parties/red-cell-immunogenetics-and-blood-group-terminology/).