Transfusion Medicine and Hemotherapy最新文献

Introduction: Among pathogen inactivation methods for blood products, an ultraviolet C (UVC) irradiation has been attracting attention. We previously reported that 265 nm UV-LED (UVC-LED) effectively prevents bacterial infection. However, the effect of UVC-LED on plasma was not considered. This study aimed to explore the effects of high-dose UVC-LED irradiation, required for viral inactivation, on plasma hemostatic potential.

Methods: After irradiation of plasma with high-dose UVC-LED for 60 min, the activities of coagulation factors and coagulation inhibitors and von Willebrand factor (VWF) antigen levels were determined. VWF multimer assay and global hemostatic analysis using reconstituted blood under flow were also conducted.

Results: UVC-LED irradiation prolonged PT and activated partial thromboplastin time in a fluence-dependent manner. Fibrinogen levels and factors V and XI activities decreased to 40-47% of pre-irradiation levels. VWF multimer analysis revealed a striking reduction in high-molecular-weight VWF multimers, irrespective to ADAMTS13 activity, while VWF antigen levels showed a slight decrease. Electrophoresis under reducing conditions indicated minimal changes in the 250 kDa-VWF subunit band, suggesting that UVC-LED irradiation disrupts inter-subunit disulfide bonds in VWF multimers. Global hemostatic analysis using reconstituted blood with irradiated plasma showed a marked prolongation in primary hemostasis, indicating impaired platelet adhesion to collagen, reflecting reduced high-molecular-weight VWF multimers.

Conclusions: We demonstrated for the first time that a high-dose UVC irradiation to plasma cleaves the inter-subunit disulfide bonds of VWF multimers and reduces the molecular size. In plasma products, the balance between maintaining hemostatic activity and inactivating various pathogens by UVC irradiation is a challenge for the future.

[This corrects the article DOI: 10.1159/000502158.].

Background and objectives: Blood donor release prior to donation by a physician is mandatory in Germany according to current guidelines. Due to shortage of qualified staff, the German Transfusion Act was modified allowing the use of telemedicine. The aim of the present study was to investigate the feasibility of remote plasma donor release with respect to donor acceptance and safety.

Study design and methods: In September and October 2024, remote donor release was studied in two plasmapheresis centres. Physicians not present in the participating centres digitally evaluated donor eligibility and released donors for plasma donation. Donors were asked about the procedure by means of a questionnaire after donation. Additionally, staff had the possibility to rate the procedure at the end of the study. Donor adverse events (AEs) were recorded and their severity and causality related to plasmapheresis were rated.

Results: A total of 243 donors fulfilled the inclusion criteria and were included in the study. Rating of donation safety by donors as well as future use of telemedicine procedures was fine. Staff also welcomed the introduction of telemedicine. The possible time saving of waiting time due to the use of telemedicine was appreciated. One mild AE was reported and the rate of AEs was 0.41%.

Conclusion: Our pilot study shows that remote release of plasma donors is feasible and accepted by both donors and staff. There were no concerns about donation safety.

Background: The MNS7 (Mi^a) is a low-prevalence antigen associated with GP.Mur hybrid glycophorin, which is high in Thai populations. Consequently, anti-Mi^a, particularly anti-Mur caused by alloimmunisation is involved in transfusion medicine. In Thailand, before the first transfusion of transfusion-dependent patients with thalassemia, typing of Mi^a and Rh antigens is minimally required to provide phenotype-matched donors. A patient with Mi^a-positive phenotype encoded by GYP*Mur homozygote (do not express GPB, JENU-negative) receiving either Mi^a-negative or Mi^a-positive phenotype can produce anti-JENU, leading to difficulty in locating compatible donors. Genotyping for GYP*(B-A-B) hybrid alleles to predict the JENU-negative phenotype is alternatively implemented. This study aimed to predict the JENU-negative phenotype in multitransfused Thai patients using PCR-based coupled DNA sequencing.

Methods: Blood samples from 861 multitransfused Thai patients were included. Mi^a antigen testing was performed using serology and PCR-sequence-specific primer. GYP*(B-A-B) hybrid alleles were analyzed using Sanger DNA sequencing. Only 5 of 68 patients receiving more than 40 red cell units developed alloantibodies. The sequence analysis revealed that 60 of 68 patients carried the GYP*Mur allele, including GYP*Mur/GYPB heterozygotes (86.76%) and the GYP*Mur/GYP*Mur homozygote (1.47%). The remaining 8 patients were GYP*Thai/GYPB heterozygotes (10.29%) and GYP*Thai II/GYPB heterozygotes (1.47%). The GYP*Bun, GYP*HF, GYP*Hop and GYP*Kip alleles were not observed. One female patient with JENU-negative phenotype received 24 red cell transfusions within 1 year without alloantibody production, which might be due to the number of red blood cell (RBC) units or her disease status.

Conclusions: Concerning this study, multiple transfusions can induce alloantibody production. Therefore, phenotype-match transfusions are beneficial among patients with long-term transfusion therapy, and further investigation of the JENU-negative phenotype is suggested.

Introduction: Factors that influence neonatal transfusions are poorly understood because of individual variations in birth conditions and maternal complications during pregnancy. This study aimed to establish models that incorporate perinatal factors associated with the early prediction and timely management of conditions of infants that require transfusion.

Methods: Data were collected from electronic medical records. Infants were categorized into non-transfusion, one transfusion, two transfusions, three transfusions, four transfusions, and more than four transfusions groups based on transfusions performed during hospitalization. Models were constructed to predict the number of transfusions needed by the infants using variables that showed significant differences among different transfusion groups based on multivariable, random forest, and gradient boosting tree multiclassification tasks.

Results: Underweight status, premature birth, Apgar scores at 1 min, 5 min, and 10 min, and gestational diabetes mellitus impacted the number of transfusions required by infants. The weighted macro-average area under the curve (AUC) values of three models constructed using previously mentioned variables were as follows: multivariable multiclassification model, AUC = 0.6549/0.7282/0.7379 on training/testing/validation sets; random forest multiclassification model, AUC = 0.8037/0.7628/0.7985 on training/testing/validation sets; and gradient boosting tree multiclassification model, AUC = 0.7422/0.7038/0.7488 on training/testing/validation sets. The weighted macro-average AUC of the three models constructed using Apgar scores were as follows: multivariable multiclassification model, AUC = 0.6425/0.7044/0.7379 on training/testing/validation sets; random forest multiclassification model, AUC = 0.7659/0.7662/0.7985 on training/testing/validation sets; and gradient boosting tree multiclassification model, AUC = 0.6559/0.6251/0.7488 on training/testing/validation sets.

Conclusion: Apgar scores at 1 min, 5 min, and 10 min may be preliminary predictive factors that could be used to implement early transfusion strategies for infants after birth. Because of the limitations of the data volume, variable selection, and model performance evaluation, further optimization and improvements are necessary to develop accurate blood transfusion prediction models for infants.

Background: Patients suffering from hemolytic anemia, thrombocytopenia, and organ damage may suffer from microangiopathic anemia, also called thrombotic microangiopathy (TMA). This condition is caused by many different pathogenic mechanisms and is always life-threatening due to vessel occlusion in vital organs. Rapid and careful workup is mandatory to identify the cause of TMA. To identify patients suffering from immune-mediated thrombotic thrombocytopenic purpura (iTTP), ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) measurement is mandatory. All patients with ADAMTS13 activity below 10 IU/dL are assigned to the diagnosis iTTP and need urgent targeted treatment. Meanwhile, caplacizumab - an anti-von Willebrand factor humanized single-variable-domain immunoglobulin fragment - is approved for the treatment of iTTP. Patients with TMA and ADAMTS13 activity>10 IU/dL can be assigned to other forms of TMA such as hemolytic uremic syndrome (HUS), complement-mediated TMA (cmTMA) - previously assigned to the term atypical HUS (aHUS) - or TMA secondary to underlying diseases such as autoimmune disorders, cancer, or infectious diseases. Complement inhibition with C5 targeted treatment, such as eculizumab or ravulizumab, is approved for the treatment of cmTMA. Even more challenging may be the differential diagnosis in pregnancy, in cancer patients with complex medication and the need to rule out conditions imitating TMA such as Evans syndrome, intoxication, infection, or severe vitamin B12 deficiency.

Summary: Identifying TMA and defining the pathophysiology of TMA is urgently necessary in patients with thrombocytopenia and hemolytic anemia with or without obvious organ damage.

Key message: ADAMTS13 testing is the most important specific test to classify TMA.

Background: Chloride intracellular channel 1 (CLIC1) is expressed in endothelial cells and platelets. Loss-of-function studies suggest that CLIC1 is involved in adhesive interactions in either cell type, but the exact mechanism of CLIC1 action is still a matter of debate.

Methods: Cultured endothelial cells and platelets were probed for CLIC1 function as well as subcellular location using fluorescence microscopy, flow cytometry, and light transmission aggregometry. CLIC1 function in vivo was tested using a mouse dorsal skin fold chamber model to assess thrombus formation.

Results: Knocking down CLIC1 in endothelial cells is associated with the inability of cells to spread after attachment to the extracellular matrix. Critical to this process is the endothelial integrin αvβ3, which mediates the recruitment of CLIC1 into newly formed lamellipodia and subsequent colocalization with F-actin. Inhibiting CLIC1 with siRNA or the synthetic CLIC1 inhibitor IAA94, on the other hand, reduced F-actin formation in nascent adhesions, indicating that CLIC1 supports integrin β3-mediated cytoskeletal dynamics during endothelial cell attachment. In addition to endothelial cells, colocalization of CLIC1 with F-actin was detected in lamellipodia of platelets, which relocate CLIC1 to their cell surface in an integrin-dependent manner. Treatment with the CLIC1 inhibitor IAA94 hindered CLIC1 relocation to the platelet membrane, diminished platelet aggregation, and reduced integrin α_IIbβ₃ activation. Injecting mice with IAA94 delayed vaso-occlusion in a mouse model of photochemical thrombus formation in vivo.

Conclusion: CLIC1 is regulated by adhesive interactions with integrin ligands that cause CLIC1 to relocate to the cell membrane of endothelial cells and platelets. This process in turn appears to be relevant for integrin-mediated functions involved in platelet thrombus formation in vitro and in vivo.

Introduction: The molecular basis of the RHD gene found in serologically D- phenotype individuals differs with race/ethnicity. Therefore, we aimed to develop a single-tube multiplex PCR-sequence specific primer (multiplex PCR-SSP) to detect RHD variant alleles commonly found in serologically D- phenotype individuals in a Thai population.

Methods: In total, 205 blood samples with a serologically D- phenotype were tested using a single-tube multiplex PCR-SSP targeted RHD exons 1, 4, 7, 10, and c.1227G>A in RHD exon 9 in combination with a hybrid Rhesus box, and results were confirmed by direct DNA sequencing.

Results: In a single-tube multiplex PCR-SSP, three patterns of amplified RHD exons were observed: total deletion of the RHD gene, Asian-type DEL, and RHD-CE-D hybrid. The allele frequencies of RHD*01N.01, RHD*01EL.01, and RHD-CE-D hybrid were 83.4%, 12.9%, and 2%, respectively. All of the Asian-type DEL samples present the RHCE*C/E allele (predicted RhCE phenotype: C/E+).

Conclusion: This study successfully established a simple and reliable molecular diagnostic platform for analyzing RHD variant alleles commonly found in serologically D- phenotype individuals in a Thai population. This technique could enable broader RHD*01EL.01 (Asian-type DEL) analyses in high-prevalence areas such as Thailand and other countries in East and Southeast Asia, serving as an example for blood bank routine settings.