Blood Transfusion

Innovation in Blood Establishment Processes, Strasbourg, 2025: a Conference Report

2025-06-05T07:42:55+00:00

This report highlights the main topics discussed during the international EDQM Blood Conference on Innovation in Blood Establishment Processes, hosted by the European Directorate for the Quality of Medicines & Healthcare (EDQM) of the Council of Europe in Strasbourg, France on 14–15 January 2025. The shift from the existing European Union (EU) directives to the new Substances of Human Origin (SoHO) Regulation (EU) 2024/1938 in 2027 will allow a more unified approach across the EU. It will establish measures to set high quality and safety standards for SoHO intended for human applications, thus ensuring high levels of health protection for donors and recipients while strengthening the continuity of the supply of critical SoHO. This conference was an opportunity for participants to share and discuss experiences and innovation in blood donation and blood components. It also raised awareness of the benefits and challenges in implementing the new SoHO Regulation in the blood transfusion field.

Non-invasive fetal HPA genotyping by UMI-NGS: a robust method for antenatal diagnosis including 48 fetal DNA markers

2025-04-18T07:16:16+00:00

Background - Non-invasive fetal HPA typing is a valuable tool to identify the pregnancies at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT). Different approaches have been developed, mainly based on real-time PCR and droplet digital-PCR. Those methods have a limited ability to multiplex and require replicates due to the contamination risk. Moreover, in order to exclude false-negative results caused by insufficient cell-free fetal DNA, the presence of fetal DNA is usually assessed with a single epigenetic marker whereas large single-nucleotide variant (SNV) panels are now available to more accurately measure the sample’s fetal fraction.

Materials and methods - We developed an innovative method for the simultaneous genotyping of HPA-1, -2, -3, -4, -5, -6, -9 and 15, in combination with a panel of 48 SNV markers, based on cell-free DNA target-enrichment with specific probes. An improved accuracy using NGS sequencing was reached with the Unique Molecular Identifiers (UMIs); these molecular barcodes are short sequences used to uniquely tag each molecule in a sample library.

Results - 81 plasma samples were collected from French and Spanish pregnant women, from 10 to 40 weeks of gestation ([wg]; 4 samples <12 wg; 38 samples 13-24 wg; 39 samples >24 wg). The panel of 48 SNVs allowed a precise quantification of fetal DNA (range: 1.1%-16.1%). All samples but one gave concordant results with the confirmed HPA genotypes. One sample was discordant for HPA-2 and HPA-3, due to false negative cffDNA results for these two loci. However, a low amount of fetal fraction in that sample was effectively alerted by the SNV markers results.

Discussion - In our experience, 16 samples can be simultaneously sequenced and analyzed in a 72 hours assay. UMIs NGS sequencing of HPA and SNV markers constitutes a robust and sensitive method for non-invasive fetal HPA genotyping.

Molecular mechanism of a novel Aweak subtype in Chinese pedigrees: identification and analysis of a large genomic deletion in the promoter upstream distal region of the ABO gene

2025-08-27T09:43:58+00:00

Background - Accurate ABO typing is essential for transfusion safety, yet weak A/B subgroups continue to present diagnostic challenges. Although most weakened ABO antigen expressions are linked to missense mutations or small indels within coding regions, the contribution of non-coding regulatory variants −especially large structural alterations− remains insufficiently characterized. Standard genotyping methods, including Sanger sequencing and targeted
next-generation sequencing, often fail to detect large upstream deletions, leaving some serological-genotypic discrepancies unresolved in donors and patients. Such gaps hinder accurate transfusion risk assessment. To clarify these mechanisms, this study performed detailed ABO blood typing in a donor with an A subgroup and his family and explored the molecular basis for weakened A antigen expression.

Materials and methods - ABO phenotypes of the proband and his parents, spouse, two daughters, and son were determined using serological testing. Full-length ABO gene sequencing was then performed using third-generation single-molecule sequencing.

Results - The proband, his father, and his son displayed the Aweak phenotype. All three carried a heterozygous 12,309-bp deletion located upstream of the ABO gene promoter, along with a normal ABOA1.02 allele. The remaining family members carried genotypes ABOO.01.01/ABOO.01.01 (mother), ABOB.01/ABOO.01.02 (wife), ABOB.01/ABOO.01.01 (daughter 1), and ABOO.01.01/ABOO.01.02 (daughter 2). No variants were detected in coding regions, introns, or splice sites. Pedigree analysis confirmed that the proband inherited the ABOA1.02 allele with the 12.3-kb deletion from his father and passed it to his son.

Discussion - This study identifies, for the first time, a large 12.3-kb upstream deletion of the ABO promoter responsible for weakened erythrocyte A antigen expression. The finding expands current understanding of regulatory mechanisms underlying weak ABO phenotypes and highlights the value of advanced sequencing for transfusion safety.

High prevalence of G6PD mutations in blood donors from the Brazilian Amazon region

2025-01-22T15:31:32+00:00

Background - Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic condition caused primarily by single nucleotide polymorphisms (SNPs). It is the most prevalent enzymopathy globally and directly impacts the ability of red blood cells to respond to oxidative stress. This study aimed to determine the prevalence of G6PD variants in Amazon blood donors.

Materials and methods - A cross-sectional study was conducted at the Foundation of Hemotherapy and Hematology of Amazonas (HEMOAM) between January and June of 2024. The study analyzed 5,000 donor samples using the quantitative polymerase chain reaction (qPCR) to detect G6PD genetic variants.

Results - G6PD variants were present in 364 (7.28%) donors, with the most common being c.376A>G (3.82%), c.292G>A (1.92%), and simultaneous c.292G>A/376A>G (0.90%). Other rare variants were also identified, including c.653C>T, c.1093G>A, c.968T>C; c.632A>T; c.1429G>A; c.700G>T; c.1192G>A and c.197T>A/c.202G>A, representing 0.64% of the total. Most donors exhibiting mutations were male (71.7%), with a mean age of 34.1±11.9 years for males and 34.0±10.5 years for females. The most prevalent blood group in both sexes was O+, with a frequency of 59.7% in males and 61.9% in females.

Discussion - This study constitutes the most extensive molecular testing for G6PD mutations in the state of Amazonas, offering a comprehensive overview of G6PD deficiency (G6PDd) in the region. The estimated prevalence rate of G6PD mutations among Manaus blood donors was 7.28%, which is consistent with other findings in Brazil. In conclusion, G6PDd has the potential to compromise red blood cell quality during storage and their survival post-transfusion. This study enhanced the methods used to identify mutations impacting blood storage, with the aim of improving transfusion safety and efficacy.

Efficiency in packed red blood management for brain tumor resection: multicenter prospective cohort study (TScoreBTR)

2025-06-27T06:53:56+00:00

Background - There are no optimized patient blood management (PBM) protocols for brain tumor resection (BTR). The aim of this study was to compare the prevalence of packed red cells (PRCs) units reserved with the prevalence of transfusion during BTR and analyse preoperative anemia.

Materials and methods - Prospective observational multicentre study for adult patients who underwent elective BTR. Fourteen tertiary-level hospitals participated from March 2021 to February 2024. The primary outcomes were the prevalence of PRCs reserved and transfused, and the efficiency metrics: crossmatch to transfusion ratio (C/T ratio), transfusion probability (TP), and transfusion index (TI). The secondary outcome was the prevalence of preoperative anemia. ClinicalTrials.gov (NCT05832450).

Results - We analysed data from 1,384 patients. A percentage of 83.3% of them had PRCs units reserved, with a median (range) of 2 (1 to 8) units per patient. The prevalence of intraoperative transfusion was 6.6% (95% CI: 5.4 to 8.0%). There were a significantly inefficient processes with a high C/T ratio (14.85), low TP (7.9%), and low TI (0.14). The percentage of women requiring at least one PRCs transfusion was more than double that of men (9.3 vs 3.7%, p<0.001). The prevalence of preoperative anemia was 25.4% with a statistically significant difference in anemia seen between women and men (36.6 vs 13.6%, p<0.001). When adjusting for preoperative hemoglobin and presumptive diagnosis, the difference between women and men was not significant (OR 1.58 [95% CI: 0.94 to 2.63], p=0.083).

Discussion - Systematic PRCs unit reservation remains a common practice despite the low prevalence of transfusions for BTR in Spain. A high prevalence of preoperative anemia was found, particularly among women. We need objective criteria for PBM to allow optimal crossmatching and PRCs reservation for BTR and to subsequently reduce inefficiencies in perioperative PRCs management.

Improving blood safety: NAT-based detection of Plasmodium spp. in blood donors in endemic areas of Brazil

2025-10-24T10:49:57+00:00

Background - Transfusion-transmitted malaria remains a significant challenge in endemic areas and is a leading cause of blood donation deferral. Rigorous clinical and molecular screening is essential to ensure the safety of blood components. The presence of low-density Plasmodium spp. parasitemia in asymptomatic individuals can compromise transfusion safety and perpetuate disease transmission. This study aimed to describe malaria positivity detected by the NAT PLUS HIV/HBV/HCV/Malaria kit (Bio-Manguinhos), as well as to characterize the epidemiological profile of blood donors and the main deferral causes at a reference blood center in the Brazilian Amazon.

Materials and methods - This was a retrospective observational study using secondary data from the HemoSys database, which included sociodemographic variables, clinical screening, and self-reported malaria history from blood donors. Cases of clinical malaria were investigated among NAT PLUS-positive donors within six months before and after the reactive donation.

Results - A total of 67,114 blood donors tested using the NAT PLUS assay were included. The median age was 35 years (IQR 25-43), with a predominance of male donors (65.1%). Most self-identified as mixed race (80.5%) and had completed high school (53.3%). Malaria-related factors accounted for 2.6% of deferrals (No.=27,434). Malaria positivity detected by NAT PLUS assay was 0.01% (8/67,114), with all reactive donors being asymptomatic at screening. Most positive cases (6/8) occurred during the low-transmission period (rainy season). One donor (12.5%) developed symptomatic malaria (P. falciparum), confirmed by thick blood smear and notified in the SIVEP-Malaria system shortly after donation.

Discussion - Individuals testing positive for Plasmodium spp. by NAT PLUS assay may progress to clinical malaria post-donation, posing risks to both donor health and transfusion safety. The frequent absence of information on malaria exposure during clinical screening highlights the need for standardized protocols and molecular testing to improve early identification of at-risk donors in endemic regions.

FAR-BENE Study: pharmacoeconomics and well-being in hemophilia. Monitoring outcomes in light of pharmaceutical expenditure with focus on patients undergoing therapeutic switch

2025-07-15T09:09:36+00:00

Background - Hemophilia, a rare bleeding disorder, raises significant pharmacoeconomic challenges, particularly with the emergence of innovative therapies. This study evaluates clinical and patient-reported outcomes and expenditures in hemophilia patients focusing on those who underwent therapeutic switches between 2017 and 2023.

Materials and methods - This retrospective study included severe hemophilia patients. Expenditure was analyzed based on clotting factor consumption, while clinical well-being was assessed using ABR, NRS for pain, joint health scores (HJHS, HEAD-US) and trough plasma levels. A sub-analysis was conducted by applying different therapeutic groups. Statistical significance of differences between paired measures (pre [T0] vs post [T1]) was examined using the Wilcoxon Sum Rank test.

Results - Seventy patients were included. Total expenditure was € 12,947,580.44 in 2017 and € 12,967,576.92 in 2023. Among 45 patients who switched therapy, the median number of infusions/year significantly decreased from 156 to 91 (p<0.001), ABR from 1 to 0 (p<0.001) and NRS from 3,5 to 0 (p<0.001). Joint health did not show improvement with a slight but not statistically significant increase (HJHS from 10 to 15; HEAD-US from 7 to 8). Median trough increased from 3 IU/mL to 5 IU/mL (p=0.181). Patients were grouped for analysis based on homogeneous treatment regimens.

Discussion - This study is the first effort to conduct comprehensive analysis of the impact of therapeutic choices on well-being and cost of care in hemophilia Center. The study underscores the need for a value-based approach to hemophilia care, integrating expenditure and clinical outcomes. Adopting validated economic weight outcome in future pharmacoeconomic evaluations will be essential for decision making.

Appropriate preoperative transfusion requests: an unsolved issue

2025-10-31T10:21:26+00:00

Nearly fifty years after Friedman et al introduced the Maximum Surgical Blood Order Schedule (MSBOS) to optimize preoperative blood ordering, inappropriate transfusion requests remain a widespread issue. Despite strong evidence showing that proper MSBOS implementation reduces blood product wastage, costs, and safety risks without compromising patient outcomes, many institutions continue to overestimate transfusion needs. The recent multicentre study by Contreras-Lopez et al. involving elective brain tumour surgeries in Spain revealed substantial inefficiencies, with over 83% of patients having blood reserved but only 6.6% actually transfused. The findings underscore the persistence of poor compliance with MSBOS principles and limited use of type-and-screen protocols, particularly in low-transfusion-risk procedures. Overordering is often driven by precautionary concerns but leads to unnecessary resource consumption and increased risk of mis-transfusion. To ensure appropriateness, MSBOS protocols must be data-driven, institution-specific, and integrated into hospital-wide quality improvement systems supported by electronic health record (EHR) technology. Continuous education, multidisciplinary collaboration, and the use of computerized crossmatching and remote electronic release systems have proven effective in improving compliance and efficiency. Overall, rationalizing preoperative blood ordering through updated, evidence-based MSBOS programs and proactive anaemia management is essential to enhance patient safety, resource utilization, and transfusion practice sustainability.

Towards a value-based approach in hemophilia: indications from the FAR-BENE study

2025-12-02T11:51:18+00:00

The significant improvements in hemophilia management and treatments observed in the last decade changed expectations of hemophilia community in terms of achievable health status but also raised concern on economic implications associated with these new approaches. In this context the need of new indicators for the desired health outcomes made achievable by the transformation of treatment has been developed and suggested in the literature, providing the basis for the development of value-based healthcare in hemophilia. The FAR-BENE (Pharmacoeconomic and Well-Being in Hemophilia) study, recently published, represents an important and timely effort to bridge this gap. Even with limits, the FAR-BENE study offers a clear signal of the need and possibility to move beyond the measure of factor consumption and bleeds and implementing a value-based approaches that integrates economics aspects with comprehensive, clinical and patient-centric outcomes. A further effort is now required by the healthcare system to create the appropriate conditions to adopt and implement standardized value-based approaches, ensuring the possibility of improving the patients’ health by maximizing the healthcare resources available.

Optimizing platelet transfusion thresholds in preterm infants: a systematic review and narrative synthesis of impacts on survival and neurodevelopment

2025-08-29T09:26:21+00:00

Background - The aim of this analysis was to evaluate the impact of different platelet transfusion thresholds on short-term and long-term outcomes in preterm infants, and to inform evidence-based, individualized transfusion strategies.

Materials and methods - PubMed, Embase, and the Cochrane Library (database initiation until December 2024) were searched. Comparative studies of restrictive transfusion strategies vs liberal transfusion strategies in thrombocytopenic neonates were included. The review protocol was prospectively registered (CRD42020169262).

Results - Of 4,102 reports screened, three randomized controlled trials and two cohort studies were included (1,851 patients). Restrictive transfusion strategies did not increase short-term adverse events and may potentially reduce the incidence of mortality and severe neurodevelopmental impairment at 2 years corrected age.

Discussion - Restrictive platelet transfusion thresholds (25×10⁹/L, or even 20×10⁹/L) appear to be safe and may improve long-term prognosis. These findings support a shift toward more individualized, evidence-based transfusion practices in neonatal care.

Passive transfer of silent red blood cell autoantibodies via the placenta and breast milk: a case report

2025-05-13T07:25:04+00:00

When unexpected antibodies recognizing self red blood cell antigens are detected in individuals by a positive direct antiglobulin (DAT) test and with no evidence of haemolytic anaemia, they are called ”silent red blood cell autoantibodies (SRBCAA)”. The role of placentally transferred allo- or autoantibodies is established but less is known about the antibodies transferred via breast milk. This is a case report of a 36-week premature female neonate born to a 38-year-old G2P1 with SRBCAA. The neonate presented with anaemia without signs of infection, hemolysis, or blood loss. The mother and neonate DATs were 1+. We identified the presence of an autoantibody against red cell antigens in the mother’s plasma and breast milk. A similar reaction pattern was also observed in the neonate plasma. The current case highlights the SRBAC detected in plasma and breast milk as a potential cause of haemolytic disease of the newborn.

Neonatal alloimmune thrombocytopenia due to anti-HPA-1b and anti-HLA antibodies: diagnostic and transfusion management of a clinical case

2025-08-22T09:03:53+00:00

Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT) is a rare condition affecting approximately 1 in 1,500 pregnancies. It is caused by maternal alloantibodies directed against paternal human platelet antigens (HPA) inherited by the fetus, which can result in FNAIT and an increased risk of bleeding. In Caucasians around 80% of the FNAIT cases are caused by HPA-1a alloantibodies while anti-HPA-5b are responsible for 10-15 % of the cases.

We present the case of a full-term female neonate, born by spontaneous vaginal delivery without infectious complications or signs of fetal distress. Within the first 24h of life, a severe thrombocytopenia was discovered on neonate blood cell count (PLT=8×10⁹/L), so an alloimmune syndrome was suspected due to the severity and early onset of thrombocytopenia. The newborn underwent platelet transfusion therapy and FNAIT investigations on parental and newborn samples were performed.

Maternal screening tests for anti-HPA antibodies, using two different technologies, and HLA antibody identification assay, pointed out anti-HPA-1b antibodies together with class I anti-HLA antibodies in maternal serum. HPA genotyping confirmed incompatibility for HPA-1 antigen while HLA typing revealed the presence of a mismatch allele between mother and neonate. The diagnosis of FNAIT was proved and transfusion therapy was driven to HPA-HLA platelet selected units.

This case highlights the importance of referral to a reference laboratory equipped with diverse diagnostic tools and an efficient blood bank. Such resources are essential for accurate diagnosis and optimized treatment, particularly when rare HPA and/or HLA alloantibodies are involved.