BACKGROUND:Human platelet antigens (HPAs) are polymorphic structures on platelet membrane glycoproteins that may induce alloimmune responses after transfusion or pregnancy. Knowledge of HPA distribution in different populations is essential for improving transfusion practice and managing platelet transfusion refractoriness. MATERIALS AND METHODS:A total of 200 unrelated voluntary blood donors were included. Genomic DNA was extracted from EDTA-anticoagulated whole blood, and HPA genotyping was performed using polymerase chain reaction with sequence-specific primers. Genotype and allele frequencies were calculated, and Hardy-Weinberg equilibrium was assessed using the χ2 test. RESULTS:The most frequent genotypes were HPA-1aa, HPA-2aa, HPA-3ab, HPA-5aa, and HPA-15ab. Allele frequencies were 0.833 (HPA-1a), 0.925 (HPA-2a), 0.578 (HPA-3a), 0.923 (HPA-5a), and 0.525 (HPA-15a). The HPA-6 and HPA-9 systems were monomorphic. No significant deviations from Hardy-Weinberg equilibrium or sex-related differences were observed. DISCUSSION:The distribution of HPA alleles in Lithuanian donors is comparable to other European populations. These findings are clinically relevant for improving donor-recipient compatibility and may support the development of HPA-typed donor registries, contributing to better management of platelet transfusion refractoriness.
BACKGROUND:Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia characterized by clonal immunoglobulin M (IgM) autoantibodies that activate complement at low temperatures, leading to hemolysis. Diagnostic practices remain inconsistent, with considerable interlaboratory variability and no established guidelines. Objective - To develop a consensus-based diagnostic framework for CAD through a structured Delphi methodology, with the goal of harmonizing laboratory practices across medical centers. MATERIALS AND METHODS:A total of 30 experts in classic hematology and transfusion medicine were invited to participate in a two-round, web-based modified Delphi survey; 27 (90%) completed both rounds. A scientific board developed 37 diagnostic statements covering five domains: CAD definition, clinical evaluation, immunohematological testing, and pre-analytical and analytical procedures. Statements were rated on a 5-point Likert scale, with consensus defined a priori as a score of 4 or 5 by ≥80% of respondents. RESULTS:All 37 statements achieved consensus, with 36 (97.3%) doing so in Round 1 and the remaining one in Round 2 after re-evaluation. The panel provided recommendations on when to suspect CAD and specified necessary diagnostic tests, including C3d positivity on direct antiglobulin test (DAT) with monospecific antisera and the detection of cold agglutinins in serum. They heavily emphasized the importance of sample handling at 37°C, alongside issuing recommendations on cold agglutinin titration, transfusion management, and immune-hematologic follow-up. DISCUSSION:This expert consensus provides a standardized diagnostic approach for CAD, addressing current gaps in clinical and laboratory evaluation. Implementing these recommendations is expected to improve diagnostic accuracy and consistency, facilitating better patient outcomes and national harmonization of practices.
BACKGROUND:In the Rhesus (Rh) blood group system, D is the most immunogenic antigen. RhD-negative patients with anti-D must be transfused RhD-negative red blood cells (RBC) to avoid hemolytic transfusion. RBC of Asian-type DEL phenotype are typed as RhD-negative by routine blood group serological methods because they have very weak expression of D antigen. The prevalence of Asian-type DEL phenotypes was 30% in RhD-negative Chinese donors. Therefore, this DEL type can be transfused to RhD-negative patients with anti-D. However, there is a lack of direct evidence regarding the safety of this practice and potential mechanisms in act. MATERIALS AND METHODS:The proportion of Asian-type DEL donors that serologically tested RhD-negative was investigated by using genotyping. Furthermore, a model system for in vivo clearance was established to assess antibody-mediated phagocytosis of Asian-type DEL RBC by macrophages. RESULTS:We identified six serologically RhD-negative donors, 16 Asiantype DEL donors according to polymerase chain reaction polymerase chain reaction with sequence-specific primers (PCR-SSP), and six PCR-SSP RhD-positive donors across various regions in China. Our study revealed that antibody-mediated RBC clearance was not observed following co-culture of opsonized Asian-type DEL RBC with macrophages. DISCUSSION:Incompatible transfusion of Asian-type DEL RBC may not result in significant RBC clearance.
BACKGROUND:With advances in HIV testing and waning prevalence of the disease, policies restricting men who have sex with men (MSM) from donating blood have been eased. However, aversion towards the notion of receiving a transfusion of blood donated by MSM relative to heterosexual donors is documented. This research tested the role of perceived risk in driving such aversion. MATERIALS AND METHODS:In online experiments, 460 (Study 1) and 863 (Study 2) heterosexual participants read an article about transfusion policies and rated perceived risk of transfusions, willingness to receive a transfusion, and willingness to donate blood. In Study 1, the articles detailed eased MSM deferral policies or other transfusion policies. In Study 2, the MSM article was adapted to highlight low risk or high benefit of policy changes in an attempt to mitigate aversion. RESULTS:In Study 1, participants who read the MSM article reported significantly higher perceived risk relative to those who read about general eligibility. Perceived risk explained downstream impacts on willingness to receive a transfusion. In Study 2, neither highlighting low risk nor high benefit of MSM deferral policy changes reduced perceived risk of transfusions. DISCUSSION:This research highlights that perceived risk may drive aversion toward the notion of receiving a transfusion of blood donated by MSM. Interventions that aim to reduce perceived risk by emphasizing high benefits or low risks of easing deferral policies may not be effective. Research into other routes to mitigate negativity towards donation of blood by MSM is warranted.
BACKGROUND:Red blood cell (RBC) storage lesion is a cascade of biochemical and physical alterations that impair transfusion efficacy and safety. This study explored the role and underlying mechanism of salvianolic acid B (Sal B) against RBC storage lesion, with a specific focus on a ferroptosis-like process. MATERIALS AND METHODS:RBC from healthy volunteers were stored in MAP additive solution for 35 days, and samples were analyzed at weekly intervals. Ferroptosis was determined by the levels of cytosolic reactive oxygen species (ROS), antioxidant enzymes superoxide dismutase and glutathione peroxidase, 4-hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), and glutathione peroxidase 4 (GPX4). Storage lesion was evaluated by erythrocyte morphology, hemolysis rate, microvesicle formation, phosphatidylserine exposure, lactate dehydrogenase release, osmotic fragility, and Band 3. Ferrostatin-1 was used to verify the involvement of ferroptosis. RESULTS:The results demonstrated a time-dependent escalation of both storage lesion and ferroptosis, evidenced by biochemical changes such as increased hemolysis, phosphatidylserine exposure, ROS accumulation, 4-HNE and MDA, as well as a reduction in antioxidant capacity and protein level of GPX4. Ferrostatin-1 treatment effectively mitigated pathological changes, suggesting that ferroptosis-associated pathways may contribute to storage lesion. Notably, Sal B supplementation correlated with reduced ferroptosis markers and mitigation of storage lesion, as evidenced by preserved GPX4 levels and reduced lipid peroxidation. DISCUSSION:This study demonstrates that a ferroptosis-like process of lipid peroxidation contributes to RBC storage lesion, with GPX4 regulating erythrocyte stability. Sal B alleviates storage lesion in parallel with preservation of GPX4 and reduced lipid peroxidation, providing a potential strategy to improve the quality of stored blood.
BACKGROUND:The antigens in the MNS blood group system, presented on glycophorin (GP), are regulated by the GYPA, GYPB, and GYPE genes. Some hybrid GP can express Mia antigen, the most common being GP.Mur. Of potential clinical significance in transfusion practice, GYP*Mur homozygotes can produce anti-JENU because they lack expression of the high-frequency JENU antigen. Although serological typing using anti-Mia is very likely to identify GP.Mur, this method cannot reliably distinguish the underlying GP or confirm the zygosity of GP.Mur, which is relevant for transfusion safety. We, therefore, developed and validated a polymerase chain reaction with high-resolution melting (PCR-HRM) assay for distinguishing homozygous GYP*Mur from heterozygous GYP*Mur/GYPB and homozygous GYPB genotypes. MATERIALS AND METHODS:An HRM assay targeting exon 3 of GYP(B-A-B) hybrid genes was designed and validated using 186 Mi(a+) samples with known sequencing data. This assay was subsequently applied to 211 DNA samples from Thai blood donors, including Mi(a+) and Mi(a-) samples. RESULTS:HRM analysis showed high concordance with sequencing data in 184 of 186 validated samples. Discrepant cases were attributable to rare sequence variations that altered melting profiles. Among Mi(a+) samples not previously sequenced, 81.45% were classified as GYP*Mur/GYPB, 3.97% as GYP*Mur/GYP*Mur, 12.58% as GYP*Thai/GYPB, and 2% as other clusters, which were identified as rare variants by sequencing. All Mi(a-) samples were consistently classified as homozygous GYPB. DISCUSSION:Our PCR-HRM assay can rapidly and reliably discriminate homozygous GYP*Mur from heterozygous GYP*Mur/GYPB and homozygous GYPB genotypes. Rare or unexpected variants can be identified when DNA quality is well controlled, and appropriate quality controls are applied. Accordingly, this method may serve as a practical first-line screening tool to support transfusion safety, particularly in populations with a high prevalence of hybrid GP.
BACKGROUND:The CeRN (RHCE*02.10) allele was described as resulting from hybrid RHCE-D-CE genes, involving either exon 4 alone or exon 4 and part of exon 3. No solution allows to distinguish between the two reported CeRN alleles. The objectives of this study were to determine the existence of both alleles, their genetic sequence and their frequencies. MATERIALS AND METHODS:We investigated 17 heterozygous CeRN samples and 10 homozygous CeRN samples, and described the junction between the RHCE and RHD genes. Analysis combined classical PCR associated with Sanger sequencing, and Oxford Nanopore NGS applied to long-range PCR. We also explored CeRN allelic frequency in sub-Saharan populations from the 1000 Genomes Project and the International Genome Sample Resource. RESULTS:One CeRN allele sequence was observed, involving exon 4 alone with an RHCE-RHD junction approximately 400 base-pairs upstream of exon 4. We observed the CeRN allele in Gambian ethnic groups, with a maximum allelic frequency of 6.0% in the Fula group. DISCUSSION:The CeRN allele involving exon 4 and part of exon 3 was not observed here, supporting at least a low frequency, as our sample size limited the power to investigate this putative second CeRN variant. The homogeneity of the CeRN sequence observed in DNA samples and the high allelic frequency are consistent with a single genetic founder event in the Fula ancestral group.Nearly 20% of individuals in The Gambia have abnormal hemoglobin. Knowledge of CeRN genetic architecture and frequency may have significant implications for more precise molecular diagnostics and transfusion therapy. The probabilistic pipeline developed here, based on subset of samples for which both DNA and WGS data were available, showed that WGS low-coverage data can be used to investigate complex genetic variants in population studies.
