The HLA-B*15:730 allele differs from HLA-B*15:12:01 by a single non-synonymous nucleotide change in exon 3.

BackgroundPredictors for the successful eradication of neutralizing anti-FVIII alloantibodies (inhibitors) in hemophilia A patients receiving immune tolerance induction (ITI) therapy remain limited. Maternal microchimerism (MMc) showed potential to protect hemophilia A patients from inhibitor development.ObjectivesTo investigated the role of MMc in ITI therapy.Patients/MethodsThis observational study enrolled 121 pediatric with hemophilia A and inhibitors. MMc was determined using droplet digital PCR. Low-dose ITI (FVIII ~50IU/kg every other day) was administered, with adjunctive rituximab given to patients with higher risk clinical features.ResultsOf the 101 patients evaluable for MMc, 88 completed ITI, 18 were MMc positive (MMc+) and 70 were MMc negative (MMc-). Success was achieved in 75 (85.2%) patients, including 16 of 18 MMc+ patients (88.9%) and 59 of 70 MMc- patients (84.3%). Compared with MMc- patients, MMc+ patients had a lower peak inhibitor during ITI (median, 5.3 vs. 37.8 BU/ml, p = 0.029), less frequent rituximab use (27.8% vs. 61.4%; p = 0.011), and a shorter time to ITI success (median, 3.0 vs 9.9 months; p = 0.009). Multivariate Cox regression identified MMc+ (HR = 2.770), pre-ITI inhibitor <10BU/ml (HR = 2.663), peak inhibitor during ITI<200BU/ml (HR = 4.954) and non-large deletion/duplication F8 mutations (HR = 2.344) as independent predictors of shorter time to ITI success.ConclusionMMc was associated with more rapid ITI success in children with hemophilia A and inhibitors receiving low-dose ITI regimen, suggesting the potential role of MMc in facilitating the eradication of FVIII inhibitors.

The HLA-A*24:677 allele differs from HLA-A*24:02:01:01 by a single non-synonymous nucleotide change in exon 2.

The HLA-C*01:02:100 allele differs from HLA-C*01:02:01:01 by a single synonymous nucleotide change in Exon 7.

The HLA-B*48:09 allele differs from HLA-B*48:01:01:01 by a single non-synonymous nucleotide change in exon 1.

HLA-DPB1*1730:01 differs from HLA-DPB1*107:01:01:01 by a single non-synonymous nucleotide change in exon 4.

Objective To accurately determine the ABO blood group of samples exhibiting forward/reverse grouping discrepancies by combining first-generation(Sanger)and third-generation(long-read)sequencing technologies.Methods Five samples with ABO forward/reverse grouping discrepancies were selected.Serological testing was conducted using auto-mated blood typing instruments and the tube method.Genotyping was conducted using both Sanger and long-read sequencing technologies.Results Sanger sequencing identified specific genetic mutations in two samples,with genotypes of ABO∗BA.04/ABO∗O.01.01 and ABO∗B3.05/ABO∗O.01.02.Further analysis with long-read sequencing revealed specific muta-tions in the+5.8kb region of intron 1(c.28+5885C>T and c.28+5861T>G)in three samples where mutations were not detected by Sanger sequencing.These mutations affect the expression of the ABO antigens and are likely responsible for the ABO subgroup phenotypes.Conclusion The integration of Sanger and long-read sequencing technologies effectively identi-fies genetic variations causing ABO subtypes,providing a scientific basis for enhancing clinical transfusion safety and ensu-ring accurate blood group determination.

Introduction Platelet-derived extracellular vesicles (pEVs) are nanoscale, membrane-bound vesicles released by platelets during activation or apoptosis. They contain various bioactive and non-bioactive molecules and play significant roles in numerous physiological and pathological processes through intercellular communication, thus attracting growing attention in biomedical research.Methods This review comprehensively overviews the biogenesis, clearance, and molecular characteristics of pEVs. It also covers current methodologies for their isolation and characterization. The therapeutic implications of pEVs in key clinical settings like tissue regeneration, hemostasis, immune modulation, and vascular repair, with a focus on cancer progression, wound healing, and hemorrhagic shock management, are explored. Their role in cellular signal transduction is examined, and their functional properties are compared with other platelet-derived products such as platelet-rich plasma.Results pEVs show potential as both therapeutic agents and diagnostic biomarkers. They are involved in modulating inflammatory responses, promoting angiogenesis, and enhancing cellular repair mechanisms.Conclusion Future research should concentrate on optimizing their therapeutic efficacy, refining biomarker applications, and exploring targeted delivery strategies to fully utilize their potential in regenerative medicine, oncology, and hemostasis management.

HLA-DQB1*06:528 differs from HLA-DQB1*06:09:01:01 by a single non-synonymous nucleotide change in exon 2.

Splice-site variants within the ABO gene have the potential to impair ABO glycosyltransferase biosynthesis, leading to decreased expression of A or B antigens on the surface of red blood cells. This study characterized how four intron 6 splice-site variants-three in the A1 allele (c.374+4A>T, c.374+4A>G, and c.374+5G>A) and one in the ABO∗B.01 allele (c.374+2_374+3insT)-affect ABO pre-mRNA splicing. A combination of serologic, molecular genetic, bioinformatic, and minigene assays established a genotype-splicing-phenotype association model. Bioinformatics predictions showed that all variants impaired the recognition of the 5' splice site. Specifically, the A allele variant c.374+5G>A induced approximately 2.8% exon 6 retention, whereas the c.374+4A>G (Afinn/Aweak) and c.374+4A>T (Aweak) variants preserved approximately 6.9% and 10.2% functional transcripts, respectively. The novel B allele insertion variant c.374+2_374+3insT (Bel subtype) retained approximately 4.7% exon 6-containing transcripts, sufficient for trace B glycosyltransferase expression. Quantitative real-time PCR analysis confirmed that the transcriptional levels of the ABO gene in the ABel subtype individual carrying the c.374+2_374+3insT variant were approximately 51.7% of those in the ABO∗A1.02/ABO∗B.01 control. This study demonstrated that splice-site variants in the ABO gene reduce the abundance of functional transcripts via altered transcriptional regulation, which, in turn, leads to decreased ABO glycosyltransferase expression, ultimately resulting in weak antigen phenotypes of varying intensity.

ABSTRACTThe HLA‐C*01:250 allele differs from HLA‐C*01:02:01:01 by a single non‐synonymous nucleotide change in exon 7.

[Objective] To analyze changes in Rh system antibodies among antibody-positive patients and evaluate the efficacy of Rh phenotype-matched electronic cross-matching (hereinafter referred to as Rh-ECM). [Methods] A retrospective analysis was performed on antibody screening data of 48 254 patients in our hospital from December 2023 to March 2025. The antibody screening results were compared between the pre-application phase (n=46 346, control group) and post-application phase (n=48 254, experimental group) of Rh-ECM technology, focusing on the changes in the proportion of Rh system antibodies, with statistical analysis conducted using SPSS 26.0 software. Meanwhile, the initial and re-examination situations of Rh antibody in the antibody screening of approximately 20 000 person-times each before (June 2019 to June 2020, n=21 048) and after (July 2020 to April 2021, n=20 965) of Rh-ECM were evaluated to explore the influence of Rh-ECM on the detection rate of Rh antibody. [Results] After Rh-ECM implementation, 345 positive cases (0.7%) (345/48 254) were detected among 48 254 patients, primarily consisting of mns system antibodies (128 cases, 37.1%) (128/345) and rh system antibodies (95 cases, 27.5%) (95/345). Before Rh-ECM implementation, 199 positive cases (0.4%) (199/46 346) were detected among 46 346 patients, with rh system antibodies accounting for 97 cases (48.7%) (97/199). The difference in the composition ratio of Rh antibodies between the two phases was statistically significant (P<0.001), and the relative risk ratio of Rh antibody detection after Rh-ECM implementation was 56.5% compared to before. Another set of data analysis showed that before Rh-ECM, there were 37 cases with initial positive results and 8 cases with re-examination positive results; after Rh-ECM, these numbers were 44 and 2 respectively There was a statistically significant difference in the re-examination positive rate of Rh antibodies between the two stages (P<0.05). [Conclusion] The implementation of Rh-ECM technology significantly reduced the proportion of Rh system antibodies among patients with positive antibody screening results. This suggests that Rh-ECM can effectively reduce the detection rate of Rh antibodies, which may be related to the reduced risk of antibody production due to Rh-matched transfusion, thus improving transfusion safety. Therefore, Rh-ECM is worthy of broader promotion in clinical transfusion testing.

ABSTRACTThe HLA‐B*40:01:82 allele differs from HLA‐B:40:01:01 by a single synonymous nucleotide in exon 4.

In maintaining normal function and activation processes, glycolysis, lipid metabolism, and amino acid metabolism play key roles in the energy demand of platelets. In the resting state, platelets primarily rely on glycolysis and aerobic oxidation to generate energy. Upon activation, platelets preferentially utilize glycolysis, as it can more rapidly provide the required ATP. In addition to glycolysis, platelets can also utilize glycogen and fatty acids as additional energy sources. The ATP provided by fatty acid oxidation is crucial for platelet activation. Additionally, during platelet storage, distinctive changes in energy metabolism occur. In the early stages of storage, platelets primarily rely on glycolysis and the pentose phosphate pathway (PPP) to generate energy. In the mid-storage phase, there is an increase in tricarboxylic acid cycle (TCA) metabolism. In the later stages of storage, cellular metabolism gradually declines. The regulation and flexibility of these metabolic pathways play a critical role in the survival and function of platelets in different states.

Cytomegalovirus (CMV) is a prevalent virus that causes substantial morbidity and mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although letermovir (LTV) prophylaxis has revolutionized CMV management, clinically significant CMV infection (cs-CMVi) after letermovir cessation presents a new challenge. Effective CMV control is heavily dependent on the reconstitution of CMV-specific cell-mediated immunity (CMI); however, there is a lack of reliable immunologic biomarkers for identifying cs-CMVi after LTV withdrawal. The aim of the present study was to determine how different CMV preventive regimens and cs-CMVi impacted CMV-CMI reconstitution and the risk factors for late-onset cs-CMVi after LTV cessation. The patients were divided into the preemptive therapy (PET, n = 55) and LTV (n = 23) groups. LTV was significantly more effective at decreasing the cumulative incidence of cs-CMVi than PET (4.3% vs. 65.4%, p < 0.01) within 100 days post-allo-HSCT. Meanwhile, after day 100, the cumulative incidence of late-onset cs-CMVi was higher in the LTV than in the PET group (26.1% vs. 7.3%, p = 0.02). We found that LTV delayed the reconstitution of CMV-specific CD8+ T cells. Patients who experienced cs-CMVi had lower CMV-specific interferon (IFN)-γ+CD4+ T-cell counts than those who did not develop cs-CMVi. Patients with CMV disease had the lowest numbers of CMV-specific polyfunctional CD4+ T cells. Polyfunctional CMV-specific CD4+ T-cell count < 2.01 cells/µL might predict late-onset cs-CMVi after LTV cessation (50.0% vs. 7.69%, p = 0.04). Our findings establish an association between CMV prophylaxis, cs-CMVi, and CMV-specific T-cell response reconstitution post-allo-HSCT.

The HLA-B*15:11:08 allele differs from HLA-B*15:11:01 by a single non-synonymous nucleotide change in exon 4.

OBJECTIVE:Colonization by carbapenem-resistant Klebsiella pneumoniae (CRKP) is associated with the risk of developing CRKP infection. Whether infected strains come from colonized strains is not well known. METHODS:An observational, prospective cohort study (July 2022 to June 2023) was conducted on intensive care unit (ICU) patients undergoing rectal CRKP colonization screening. Antibiotic susceptibility testing, modified carbapenem inactivation method, serum bactericidal and phagocytic assays, and whole genome sequencing were performed on intestinal colonization and infection site isolates from 7 ICU patients. RESULTS:Among 412 ICU patients included, 88 were screened positive. Out of 82 patients who experienced colonization during hospitalization, 41 (50.0%) developed infections. 14 CRKP strains isolated from 7 patients were positive for carbapenemase in modified carbapenem inactivation method and exhibited similar resistance and virulence phenotype. Whole genome sequencing showed that the 14 CRKP, including 2 ST11, 2 ST15, and 10 ST5422, were blaKPC-2 producing strains, and the genetic environment surrounding blaKPC-2 was the same. Comparing the colonized and infected strains of the same patient, they both carried identical virulence genes, but the resistance genes and plasmids were not completely the same, however, the single nucleotide polymorphisms differed by less than 10. CONCLUSIONS:Nosocomial CRKP infection should focus on preventing intestinal colonization in hospitalized patients. Small single nucleotide polymorphisms differences indicated that the infected strain may have originated from the colonized strain, but some resistance genes or plasmids may have been obtained during this transformation process. blaKPC-2-carrying K. pneumoniae ST5422 was first reported in our study, and its genetic relationship was closely related to the clone strain ST11.

BACKGROUND:Platelet storage lesions (PSLs) impact platelet lifespan and transfusion quality. This study explores platelet storage metabolism for potential interventions. METHODS:Samples were collected on days 1, 3, and 5 for untargeted metabolomics analysis to identify metabolites that differ with storage time and potential metabolic pathways. The activities of glucose-6-phosphate dehydrogenase (G6PD) and cyclooxygenase-1 (COX-1) in platelets during storage were measured. Meanwhile, flow cytometry was used to assess changes in apoptosis and mitochondrial function of stored platelets treated with either a G6PD inhibitor, a G6PD activator, or a COX-1 inhibitor. Platelet aggregation was used to evaluate platelet function. Megakaryocyte/platelet-specific G6pd knockout mice were used to assess the role of G6PD in PSLs. RESULTS:The pentose phosphate pathway (PPP), arachidonic acid metabolism, and linoleic acid metabolism were enriched during storage. A total of 4832 platelet metabolites and 6468 plasma metabolites were identified, with 44 and 108 showing nominally significant changes respectively. An increase in G6PD activity was observed at the early stages. Inhibiting G6PD with G6PDi-1 damages mitochondria, increases phosphatidylserine externalization, and impairs platelet aggregation. Mouse G6pd-/- platelets exhibited increased PSLs. Activation of G6PD with AG1 reduces mitochondrial reactive oxygen species (mtROS) and phosphatidylserine externalization while enhancing platelet aggregation. Additionally, although COX-1 activity in the arachidonic acid metabolism pathway increases at the early stage, its inhibition by the COX-1 inhibitor aspirin does not significantly alter PSL-related indicators. CONCLUSION:The pentose phosphate pathway maintains platelet mitochondrial function via G6PD regulation, making G6PD a critical target for reducing PSLs.

HLA-C*08:294 allele differs from HLA-C*08:01:01:01 by a single non-synonymous nucleotide change in exon 3.