Vox Sanguinis最新文献

Plasma-derived medicinal products (PDMPs) are recognized internationally as essential medicines required to treat various acute and chronic conditions including congenital deficiencies of plasma proteins in haemophilia and primary immune deficiency. Global provision of these medicines is dominated by a small number of commercial companies, influencing the price and availability of the products. Achieving a level of strategic independence from this dominance is now seen as a public health priority in many countries. During the Regional Congress of the International Society for Blood Transfusion (ISBT) in Cape Town, South Africa, in November 2023, around 50 delegates from 24 countries participated in a workshop (WS) organized jointly by the International Plasma and Fractionation Association (IPFA) and the ISBT Working Party on Global Blood Safety on pathways towards provision of PDMPs from domestic plasma independent of commercial purchase in the open market. The WS was structured around three themes, each addressed by a separate group: Quality/safety requirements for plasma for fractionation (PfF) Stepwise access for safe plasma proteins Approaching contract fractionation A synthesis of conclusions from these groups included the following: The need to acquire support from government authorities for a national plasma policy, recognizing the difficulties posed by unstable political and bureaucratic environments. The value of embedding plasma and PDMPs within a patient blood management (PBM) paradigm to promote optimal clinical use of PDMPs. Training of blood/plasma collection personnel in the relevant principles of Good Manufacturing Practice (GMP), coupled with regulatory oversight of plasma product production in the engaged jurisdictions. Appreciation that limited access to contract fractionation may necessitate a stepwise approach, which may include small-scale preparation of versions of essential plasma proteins as an intermediate phase towards the manufacture of industrial-scale PDMPs from domestic plasma.

Background and objectives: Blood donor questionnaires are tools used to screen prospective blood donors to determine their eligibility. There are limited data regarding blood donor questionnaires and infectious disease screening of the blood supply in Latin American countries. This study aimed to survey donor centres in Latin American countries to learn more about blood donor screening and infection assessment.

Materials and methods: An international team of transfusion medicine professionals including medical directors and supervisors who work or collaborate with Latin American donor centres, called 'Comité de Investigación en Medicina Transfusional', designed a survey (16 questions) to characterize blood donor eligibility in Latin America.

Results: Eighty-two institutions from 14 Latin American countries responded to the survey. Most donor centres (66%; 54 of 82) had a donor deferral percentage between 5% and 25%, and the most common causes of deferrals were low haemoglobin and high-risk behaviour. Most donors in blood centres were directed family donors compared with voluntary donors. Infection evaluation included mostly serologic assessment (81%; 30 of 37) for human immunodeficiency virus (HIV), Hepatitis B, Hepatitis C, Treponema pallidum and Trypanosoma cruzi rather than nucleic acid tests (5%; 2 of 37).

Conclusion: Heterogeneity exists in donor selection and infectious disease screening in Latin American countries. This survey provides valuable information to understand Latin American blood centre practices.

Background and objectives: Facemasks represent an essential measure of prevention against the spread of infectious diseases; however, they lessen the ability to convey and understand emotions through facial expressions. In blood donation settings, facemask wearing could interfere with professionals' tasks, reduce the satisfaction of blood donors and affect their future blood donation behaviour. This preliminary cross-sectional study explored the association of mandatory facemask wearing with the quality of the blood donation process at the end of the coronavirus 2019 (COVID-19) pandemic.

Materials and methods: A sample of 615 voluntary unpaid Italian blood and plasma donors completed an online survey assessing their attitude towards facemask wearing, the perceived distress due to facemasks in the different steps of the donation process, self-reported vasovagal reactions after donation and the intention to donate again.

Results: Nearly 24% of donors reported a worsened quality of the donation process due to facemask wearing, and 36% reported moderate to severe distress during the donation itself. Donors with a more negative attitude towards facemasks reported a worse donation experience, mainly related to the interactions and the communication with physicians and nurses, and a higher probability of experiencing vasovagal reactions at their last donation. No significant correlations were observed between negative facemask attitudes towards facemask wearing, distress or future intention to donate blood/plasma.

Conclusion: Facemasks have worsened the quality of blood and plasma donations for one fourth of donors, confirming the interference with the quality of communications and relationships with healthcare professionals.

Background and objectives: Preoperative red blood cell (RBC) transfusions increase post-operative venous thromboembolic (VTE) events. Erythropoietin-stimulating agents (ESAs) increase VTE risk in cancer patients; we aimed to assess ESA versus RBC-associated VTE risks in a broad population of surgical patients.

Materials and methods: We queried TriNetX Diamond Network from 2006 to 2023, comparing patients with anaemia within 3 months preoperatively who received preoperative ESAs with or without intravenous (IV) iron to patients who received preoperative RBCs. Sub-analyses included (1) all surgeries and (2) cardiovascular surgeries. We propensity score matched for demographics, comorbidities, medical services, post-treatment haemoglobin (g/dL) and, for all-surgery comparisons, surgery type. Outcomes included 30-day post-operative mortality, VTE, pulmonary embolism (PE), disseminated intravascular coagulation (DIC) and haemoglobin.

Results: In our 19,548-patient cohorts, compared with preoperative RBC transfusion, ESAs without IV iron were associated with lower mortality (relative risk [RR] = 0.51 [95% confidence interval (CI), 0.45-0.59]), VTE (RR = 0.57 [0.50-0.65]) and PE (RR = 0.67 [0.54-0.84]). Post-operative haemoglobin was higher in the ESA without IV iron cohort compared with the transfusion cohort (10.0 ± 1.4 vs. 9.4 ± 1.8 g/dL, p = 0.002). Cardiac surgical patients receiving ESAs with or without IV iron had lower risk for post-operative mortality, VTE and PE (p < 0.001) than those receiving RBCs. Post-operative haemoglobin differed between patients receiving ESAs with IV iron versus RBCs (10.1 ± 1.5 vs. 9.4 ± 1.9 g/dL, p = 0.0009).

Conclusion: Compared with surgical patients who were transfused RBCs, ESA recipients had reduced 30-day post-operative risk of mortality, VTE, PE and DIC and increased haemoglobin levels. IV iron given with ESAs improved mortality.

Background and objectives: Missense variants in exon 7 of the ABO gene can lead to the formation of cisAB alleles. These alleles encode glycosyltransferases (GTs) capable of synthesizing both A and B antigens. In this study, we report the discovery of a novel cisAB allele and characterize it at molecular, protein and serological levels.

Materials and methods: Blood and DNA samples from the proband and seven relatives were examined using standard and modified ABO phenotyping, polymerase chain reaction-restriction fragment length polymorphism and ABO gene sequencing. We assessed the impact of the p.Leu324Ser variant on the protein structure of the mutant GT using bioinformatics tools.

Results: Molecular tests revealed a c.971T>C (p.Leu324Ser) variant in the ABO gene in five of the eight individuals. This variant results in a GT that produces more A antigens and fewer B antigens. Bioinformatics analysis suggests that the amino acid substitution (p.Leu324Ser) could potentially affect enzymatic activity and specificity of the GT.

Conclusion: We identified a novel cisAB allele resulting from a c.971T>C variant in the ABO gene. This variant led to the expression of an AB_weak phenotype.

The Asia-Pacific Plasma Leaders' Network (APPLN) plays a crucial role in addressing the regional shortage of plasma-derived medicinal products (PDMPs), particularly in low- and middle-income countries (LMICs). It provides a platform for experts to share their expertise and drive multi-stakeholder collaborations. While several PDMPs are acknowledged by the World Health Organization (WHO) as life-saving therapeutics on the Model List of Essential Medicine for treating various chronic and acute life-threatening diseases, there are still many inadequacies in the availability and affordability of PDMPs. These challenges arise from insufficient domestic supplies of plasma suitable for fractionation, as well as a lack of technical and financial capabilities to implement contract or domestic plasma fractionation programmes. At two separate dialogue forums organized by the APPLN in 2023, experts discussed the unmet needs of PDMPs for individuals living with haemophilia and immunodeficiencies in the region. They also highlighted the limited access to early diagnosis and patient-centred care in several LMICs. To address these issues, there is an urgent need to increase the availability of high-quality domestic plasma for fractionation. Adopting a stepwise approach to utilize unused recovered plasma and establishing contract fractionation programmes could be viable strategies to potentially enhance PDMP availability in LMICs. However, achieving this goal requires improving existing domestic infrastructures for blood collection, implementing adequate policy reforms and fostering competent local leadership. Ultimately, there is no 'one-size-fits-all' strategy for securing safe plasma proteins for all patients in need. Collaborative efforts are essential for achieving progressive self-sufficiency in PDMPs.

Background and objectives: Recently, third-generation long-read sequencing technology has been increasingly applied to the detection of various blood group systems. Because of its long read length and use of single-molecule sequencing, it is capable of obtaining the sequences of blood group genes in their entirety as well as of distinguishing haplotypes. Therefore, here, we collected ABO blood group samples that were difficult to classify serologically and analysed the sequences of the coding regions of the ABO genes as well as the sequences upstream and downstream of the coding regions.

Materials and methods: Samples with ABO antigen typing and reverse serum typing discrepancies were screened in a total of 21 patients. All samples were subjected to serological testing and preliminary ABO genotyping (polymerase chain reaction with sequence-specific primers [PCR-SSP]), followed by single-molecule real-time (SMRT) sequencing to obtain complete ABO gene sequences. PCR sequence-based typing (PCR-SBT) was performed to validate the results.

Results: Of the 21 samples, 15 had common ABO types, and 6 had rare ABO subtypes. One new allele, ABO*B.NEW (c.861C>T), and one allelic base recombination event was identified. Forty-two haplotype sequences were obtained via SMRT sequencing with intronic single-nucleotide variants (SNVs) specific to the ABO allele, and all of the exon region sequences were consistent with the PCR-SBT results.

Conclusion: SMRT sequencing is capable of accurately obtaining complete ABO gene sequences, distinguishing haplotypes and identifying allelic recombination.

Background and objectives: Manual blood exchange (MBE) is a leukoreduction therapy for hyperleukocytosis in Bordetella spp.

Infection: We describe the impact of BE on clinical and biological parameters in critically ill children with malignant pertussis.

Materials and methods: This is a monocentric retrospective review of patients with malignant pertussis infection treated with MBE. It describes the evolution of haemodynamic, ventilatory, haematologic and metabolic characteristics before and after MBE.

Results: Between January 2006 and December 2021, nine patients (median age 43 days, range: 13-80 days) had 16 MBE for malignant pertussis. All patients were mechanically ventilated, and 7/9 patients developed pulmonary hypertension during their paediatric intensive care unit (PICU) stay. Overall, 3/9 patients survived, and the mean PICU length of stay was 8.5 days (range: 1-52 days). We found a significant reduction of the leukocyte count (pre-MBE: 61.8 G/L [interquartile range (IQR): 55.8-74.8] vs. post-MBE: 19.4 G/L [IQR: 17.7-24.1]; p ≤ 0.001) and significant oxygenation improvement (pre-MBE SpO₂/FiO₂: 190 [IQR: 106-200] vs. post-MBE SpO₂/FiO₂: 242 [IQR: 149-250]; p = 0.03). The main side effects were a significant reduction of thrombocytes (pre-MBE: 411 G/L [IQR: 166.5-563.5] vs. post-MBE: 66 G/L [IQR: 46-82.5]; p = <0.001) and of ionized calcium (iCa) (pre-MBE iCa: 1.3 [IQR: 1.22-1.37] vs. post-MBE iCa: 1.25 [IQR: 1.85-2.24]; p = 0.03).

Conclusion: MBE efficiently reduces leukocytes and improves oxygenation in severe Bordetella pertussis infection in infants. Careful monitoring of calcium and thrombocytes seems mandatory.

Background and objectives: In Japan, apheresis donation of plasma is allowed to a maximum of 24 times a year, and plateletpheresis are counted as two plasmapheresis donations. Diversion of the initial blood flow is conducted for all donations, and additionally, blood remaining in apheresis machine circuit is lost. Here, we aimed to investigate on the health impact of frequent apheresis donations, as measured by the serum ferritin (sFer).

Materials and methods: A total of 538 male apheresis donors and 538 age-matched whole blood (WB) donors, who gave informed consent to join the study, were enrolled. sFer were compared, according to age. Another group of 19 apheresis donors were followed during four consecutive donations.

Results: About half (48%) of repeat male apheresis donors had iron deficiency (sFer < 26 ng/mL), compared with lower rates (13.9%) among male WB donors. It was evident in all age groups, except for teenagers, possibly because of the lower number of donations. Follow-up of the 19 donors for 4 months revealed a progressive decrease in sFer.

Conclusion: Blood remaining in the apheresis machine circuit and diversion of the initial blood flow have been implicated in iron deficiency for many years. Taking the present results, the manufacturer of apheresis equipment was requested to improve it to allow rinseback of the remaining blood, which was achieved only for plateletpheresis. Until further improvement, plasmapheresis frequency was reduced to 12 times a year. Additional measures, such as oral supplementation of iron, need to be considered.