Vox Sanguinis最新文献

Background and objectives: Iron deficiency (ID), with or without anaemia, affects over 1 billion people globally. Early detection is essential, but current diagnostic tools may be costly, logistically complex and not widely accessible. This study evaluates low haemoglobin density percentage (LHD%), derived from mean corpuscular haemoglobin concentration (MCHC) in routine complete blood counts (CBCs), as a no-added-cost, accessible alternative for ID screening.

Materials and methods: We retrospectively analysed 3526 adult patient records (January-April 2025) from a single-centre institution, including those with iron panel and CBC performed within 24 h. Patients were categorized as Normal, ID, ID anaemia (IDA) or anaemia without ID (AwoID). LHD% was calculated and assessed across groups using receiver operating characteristic (ROC) curve analyses for cutoff determinations.

Results: Median LHD% increased progressively from the Normal group (2.99%) to the IDA group (6.71%). ROC analysis showed modest but acceptable diagnostic performance: area under the curve (AUC) was 0.677 overall, 0.687 in non-anaemic and 0.684 in anaemic subjects. Specific LHD% cutoffs varied by context: >4.48% for general screening (61% sensitivity, 67% specificity), >7.02% for donor screening (95% specificity) and >3.74% for anaemia workup (75% sensitivity).

Conclusion: LHD% shows potential as a context-specific, no-added-cost screening tool for ID using existing CBC data. While its diagnostic performance is modest, its scalability and accessibility could support broader public health screening efforts. Further prospective validation is recommended.

Background and objectives: The demand for intravenous immunoglobulin (IVIG) is increasing, but supply is limited. Some residual protein contaminants such as prekallikrein activator (PKA) and immunoglobulin A (IgA) can cause severe adverse effects, necessitating a more efficient purification process with high recovery and fewer impurities.

Materials and methods: We used IVIG intermediate from caprylic acid precipitation as the starting material. Diatomite adsorption and two-step anion exchange chromatography (AEX) were employed to remove PKA, Factor XII, prekallikrein and kallikrein. Three resins for the second-step flow-through mode AEX were evaluated, and the loading conditions were optimized by Design of Experiments (DoE) and high-throughput screening experiments to better remove IgA and immunoglobulin M (IgM). Pilot-scale experiments validated the feasibility of the optimized process.

Results: Diatomite adsorption (300 g/kg, 1 h) and two-step AEX could remove PKA, Factor XII, prekallikrein and kallikrein to below the limit of detection. The best AEX resin and optimal loading condition (pH 6.0 with 3.0 mS/cm conductivity) to remove IgA and IgM were obtained. As a result, IgA and IgM could be reduced to 3.83 and 10.70 μg/mL, respectively, with the immunoglobulin G (IgG) recovery over 86.9%. The 800-L pilot-scale results demonstrated successful process scale-up, achieving robust IgG recovery and effective impurity removal for IVIG production.

Conclusion: The combination of diatomite absorption and optimized two-step AEX resulted in IVIG preparation with enhanced purity and high recovery.

Three technologies are currently under active development for pathogen inactivation of red cell concentrates or whole blood (WB): the Intercept technology using S-303 as an inactivating chemical; the Theraflex technology using UV-C illumination; and the Mirasol technology using riboflavin and UV light. For the UV-C technology, no in vivo data are available. For the other two technologies, recovery, survival and life span of the treated red blood cells (RBCs) are shortened but are within objective requirements, including a 24-h recovery >75%. S-303-treated RBCs were transfused in various patient groups and, so far, showed no relevant differences in the clinical endpoints. In early studies, S-303-reactive antibodies were observed, which prompted changes in the inactivation process, and no further antibody formation was seen. The one published study with the riboflavin/UV procedure showed good effectiveness of treated WB, with haemoglobin increment similar to that of untreated WB. When considering potential implementation of pathogen inactivation strategies, a balance should be struck between microbiological safety, component quality and cost. None of the current technologies is in a stage for large-scale blood bank application, either because of limited availability of evidence of satisfactory in vitro quality data or because of the ongoing requirement of clinical trials in a broad spectrum of patients.

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: 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: 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: Arbovirus infections are a major public health concern in Brazil and an ongoing blood safety concern. Periodic outbreaks of such infections are common in the general population. This study aimed to establish the rates of dengue, chikungunya and Zika virus (DENV, CHIKV, ZIKV) RNAemia among blood donors at six public blood centres during the 2019-2020 and 2020-2021 outbreak seasons.

Materials and methods: Residual minipool samples from nucleic acid testing (NAT) screening for human immunodeficiency virus, hepatitis B virus and hepatitis C virus were further pooled to form pools of 18 donation samples and tested using a Grifols research-use-only triplex transcription-mediated amplification assay for DENV, CHIKV and ZIKV RNA to establish the rates of RNAemia and infection incidence. We used these rates and estimated the durations of RNAemia, juxtaposed with public health reporting of cases.

Results: A total of 5,616 minipools representing 101,088 donations were tested. During both outbreak seasons, the highest rates of DENV RNAemia were observed in Ribeirão Preto, at 122/100,000 donations (95% confidence interval [CI]: 66-224) and 100/100,000 (95% CI: 52-189), respectively, with DENV RNAemia also detected in São Paulo, Recife and Manaus in the 2019/2020 season and in the latter two during the 2020/2021 season. CHIKV RNAemia was detected in Recife and ZIKV RNAemia in Manaus during the 2020/2021 season. The estimated numbers of DENV, CHIKV and ZIKV RNAemic components released for transfusion over the study period were 338, 22 and 6, respectively.

Conclusion: Surveillance for arbovirus RNAemia in blood donors is a useful adjunct to public health surveillance, particularly when surveillance systems are under strain, and has implications for transfusion safety.