Transfusion Medicine最新文献

Background: Extracellular vesicles (EVs) have procoagulative properties. As EVs are known to accumulate in stored blood products, we compared the EV content and coagulation capacity of leukoreduced cold-stored whole blood (CSWB) with current prehospital and in-hospital component therapies to understand the role of EVs in the haemostatic capacity of ageing CSWB.

Materials and methods: Blood was obtained from 12 O RhD-positive male donors. CSWB was compared with in-hospital component therapy of red blood cells (RBCs), OctaplasLG and buffy-coat platelets and prehospital component therapy of RBC and lyophilized plasma. Samples were drawn on Days 1 and 14 of CSWB and RBC cold storage. Blood count, haemolysis markers, rotational thromboelastometry, sonorheometry and thrombin generation were analysed. EVs were analysed using nanoparticle tracking analysis and cellular origin was determined using imaging flow cytometry.

Results: There was a trend towards increased production of both platelet and RBC-derived EVs during CSWB storage. Particle count increased during storage, whereas thrombin generation slowed down and in viscoelastic assays, clotting times prolonged, clot formation became impaired, and stiffness of the resulting clot decreased.

Conclusion: Both platelet and RBC-derived EVs increased in number in CSWB during storage. This did not appear to compensate for the in vitro decreasing haemostatic capacity of ageing CSWB, suggesting EVs produced during storage may not have active procoagulative effects, but rather reflect the ageing of blood cells.

Objectives: To report a delayed case of severe haemolytic disease of the foetus and newborn (HDFN) due to Anti-Ce.

Background: HDFN due to maternal antibodies is potentially fatal. As a result, antibody levels and foetal anaemia are periodically monitored and risk assessed throughout pregnancy. HDFN due to Anti-Ce is rare.

Case report: A 29-year-old Caucasian female with low titre Anti-Ce and Anti-e antenatally delivered a term baby girl that required multiple transfusions and hospital admissions early in life. The apparent clinical severity of HDFN resulted in investigative testing of a maternal admission sample at delivery for titre levels. Anti-Ce was identified as the cause of HDFN in this case, following an eightfold increase in titre levels from week 28 gestation (titre = 4) to term (titre = 32).

Discussion: The severe HDFN outlined in this case was unexpected due to the antibody specificity and low titres antenatally. The Anti-Ce with a titre of 32 implicated in this study is on the threshold for specialist foetal team involvement and vigilant monitoring as per BSH guidelines.

Conclusion: Anti-Ce titre monitoring beyond 28 weeks gestation and specialist foetal team involvement early in pregnancy should be considered despite current BSH Guidelines, along with extended neonatal monitoring.

Background: Anaemia remains the main cause of deferral in blood donation. However, in Morocco, pre-donation haemoglobin measurement is not systematic.

Objectives: The aim of this study was to determine the prevalence of anaemia and associated factors such as sex, age and iron deficiency among blood donors in eastern Morocco in order to improve donor management practices.

Methods/materials: The study involved 2013 blood donors from the BRO Biobank. Blood samples were analysed using an automatic blood cell analyser for complete blood counts. Serum ferritin was measured by chemical and immunological analyser. Anaemia was defined as haemoglobin levels less than 13 g/dL in men and 12 g/dL in women, according to the WHO recommendation.

Results: The overall prevalence of anaemia in eastern Morocco was 9.84% and it varied significantly by region. The majority of anaemic individuals were iron-deprived (88.64%). Anaemia was much higher in females (14.74%) than in males (5.46%). The highest prevalence of anaemia among females was in the age group of 18-20 years (25.2%), while among males it was in the age group of 61-65 years (18.52%).

Conclusions: The high prevalence of anaemia among blood donors in eastern Morocco highlights the need to implement pre-donation haemoglobin assessment in donor selection guidelines and to consider optional ferritin testing for at-risk populations. Moreover, educating donors about iron deficiency and iron-rich diets is essential for sustaining donor health and eligibility.

Objectives: Investigation of the interference of mezagitamab in serological pre-transfusion testing and the use of DaraEx to overcome it.

Background: Administration of anti-CD38 antibodies is a state-of-the-art therapy for patients diagnosed with multiple myeloma. However, treatment with the currently approved anti-CD38 antibodies regularly results in widespread agglutination of red blood cells in serological pre-transfusion testing, making the determination of irregular antibodies and timely transfusion of compatible blood a challenge. Mezagitamab, a novel monoclonal anti-CD38 antibody, is currently under clinical investigation, not only for the treatment of multiple myeloma but also for other indications such as generalised myasthenia gravis.

Methods/materials: Mezagitamab or daratumumab spiked plasmas, with or without irregular antibodies, were tested in column agglutination technique cards. DaraEx was used to mitigate occurring interferences.

Results: Mezagitamab interferes with the indirect antiglobulin test, with comparable titers but weaker reaction strengths than daratumumab. DaraEx, a reagent containing Fab fragments of an anti-CD38 antibody, is able to completely overcome this interference in the antigen masking indirect antiglobulin test (AMIAT). DaraEx treatment does not interfere with tested irregular antibodies.

Conclusion: All novel anti-CD38 antibodies, such as mezagitamab, have the potential to interfere in serological pre-transfusion testing. While masking only one epitope, DaraEx has so far been an effective mitigation for all clinical anti-CD38 antibodies.

Iron deficiency anaemia (IDA) poses a significant health challenge during pregnancy, affecting up to 30% of pregnant women in the UK. It has been linked to poor health outcomes for the mother, foetus, and the infant. Despite its prevalence and impact, current diagnostic and therapeutic approaches are limited. Ensuring an adequate iron status in pregnancy requires prompt investigation and treatment whilst avoiding excessive iron supplementation and its associated side effects. Hepcidin, a key regulator of iron trafficking in the body, has emerged as a promising candidate for tailoring iron supplementation to individual needs and responsiveness. However, current research on hepcidin-based approaches yields mixed findings, necessitating a comprehensive review to elucidate its potential utility in guiding iron therapy for pregnant women with IDA. This literature review seeks to synthesise existing evidence to explore the role of hepcidin in personalised iron supplementation for pregnant women with IDA and to identify avenues for future research to pave the way for improved management of IDA in pregnancy.

Introduction: The quality of packed red blood cells (PRBC) is influenced by various factors such as the collection and processing method, storage conditions, type of bag materials used, anticoagulant properties, and donor characteristics. Studies have indicated that haemolysis in stored RBC bags is linked to male sex, older age, high haemoglobin count, and increased body mass index (BMI). The study's primary objective was to investigate whether a high BMI, as per Asian Pacific criteria among donors, is associated with an elevated haemolysis rate in stored RBC. Additionally, the study aimed to examine any protective effects of different types of preservatives added to blood bags against RBC haemolysis during storage.

Methods: Stored RBCs from 100 blood donors with different BMI are analysed for haemolysis on 0, 21, and last day (35/42 days) of storage. A BMI cut-off of 23 was taken for healthy and overweight consideration in blood donors. The blood bags selected for storage were either with additive solution (SAGM) or without additive along with an anticoagulant. The association of the percentage of haemolysis with different variables like age, BMI, and Haemoglobin of the donor were analysed. The correlation between the haematocrit of the bag and haemolysis was determined.

Results: This study did not find any significant increase in the percentage of haemolysis in blood bags with higher BMI on the last day of storage (p = 0.424). The haemolysis percentage was higher in bags without SAGM than in bags with an additive solution (p = 0.000). The high haematocrit of the bag has a significant positive correlation with the percentage of haemolysis (p = 0.002). Significantly higher haemolysis in CPDA-1 bags of donor RBC units of BMI >23 groups was observed (p = 0.000) compared to those stored in CPD-SAGM bags.

Conclusion: Indian population for higher BMI, as per Asia Pacific cut-off criteria, did not significantly impact the haemolysis of blood bags. Stored RBCs with SAGM, especially of donors having BMI > 23, had a protective effect against haemolysis in blood bags. The percentage of haemolysis was positively correlated with the haematocrit of stored RBC in bags.

Background/objectives: No erythrocyte elution method developed is uniformly successful or allows elution/phenotyping together. We previously developed an elution method using deionised formamide. We modified it to be universal for various cell types and call it modified formamide-method (Fm-method). It also preserves cells for phenotyping after elution.

Materials and methods: Fm-method reagent contains deionised formamide, buffered high salt, EDTA, TE. Elution-reagent is removed by column centrifugation. Blood samples were used for development and validation. Results compared to commercial/common antibody elution/phenotyping methods.

Results: Fm-method eluted antibodies, complement, other proteins, and nucleic acids and works with erythrocytes, leukocytes, other cells. It worked better than commercial kits used for elution/phenotyping with no false positives/negatives. It did not denature Kell and Lewis antigens and could be repeated as needed on samples to recover more antibodies and clean cells for phenotyping. Western blotting, PAGE and FCM demonstrated eluted proteins were not degraded and cells remained intact.

Conclusion: Fm-method is excellent for elution and phenotyping and permits elution and phenotyping with one method and sample. It is useful for studies of various bound molecules and cell surface structures. It should be possible to elute various simple and complex carbohydrates as well. The Fm-method is efficient, inexpensive, scalable, uses common reagents. It should have excellent applications in various clinical, research, commercial settings.

Objectives: The study aimed to assess the conditions for coating RBCs with penicillin and examine the anti-penicillin reactions of random Thai patients' sera against penicillin-coated RBCs and normal sera from Thai donors testing in the presence of the drug.

Background: Penicillin-induced immunologic haemolytic anaemia (IHA) is reportedly related to possessing antipenicillin antibodies, immunoglobulin G (IgG), which has been identified in testing penicillin-coated red blood cells (RBCs). In addition, low titre penicillin antibodies, often IgM, are detected in donors by testing in the presence of a solution of the penicillin.

Materials and methods: Penicillin-coated RBCs were produced, and antipenicillin was tested against those penicillin-coated RBCs amongst random Thai patients who had strongly positive direct antiglobulin (≥3+). Additionally, sera from Thai blood donors were tested in the presence of the penicillin. These relationships were determined by comparing the numbers of penicillin-antibody positive patients with their diagnosis, sex, age and blood type.

Results: Penicillin requires a high pH to optimally adhere to RBCs that showed validated reactions with controls. Enrolment of 304 random patients, of whom 17 (5.59%) had positive antipenicillin tests using penicillin-coated RBCs. Of the 246 donor samples, 3 (1.22%) displayed positive reactivities in the presence of soluble penicillin. Furthermore, no association was discovered between the patient's characteristics and antipenicillin positivity.

Conclusions: This is the first study to develop and report on the low percentage of patients' and donors' sera without IHA. Investigating suspected cases of penicillin-induced IHA requires following our suggested method to identify clinically significant antipenicillin.

Introduction: Introduction The Hy antigen is one of ten red cell antigens belonging to the Dombrock blood group system, with an antigen frequency of almost 100% in the majority of populations. Alloantibodies to high prevalence antigens cause difficulties with antibody identification and exclusion in serological investigations.

Case presentation: This review describes the management of four antenatal cases where the presence of alloanti-Hy had been identified. Hy-red blood cell units may be required for the transfusion of patients with alloanti-Hy, but currently, there are no published reports of alloanti-Hy causing haemolytic disease of the fetus and newborn (HDFN). A previous case report involving the care and management of antenatal patients with alloanti-Hy antibodies indicates a lack of evidence that alloanti-Hy causes clinical HDFN.

Results: All cases discussed in this review demonstrate a reduction in the strength of alloanti-Hy levels as pregnancy progressed. Signs or symptoms of HDFN were not observed with any of the pregnancies.

Conclusion: Factors such as antibody levels, antigenic expression, and varying clinical responses enhance our understanding of why alloanti-Hy has not been known to cause clinical HDFN. The cases presented here aim to improve understanding of alloanti-Hy in pregnancy and how to manage such cases.

Background: At the regional transfusion service in the Region of Southern Denmark, serological investigations are primarily carried out using column agglutination techniques. This case study examines an unusual instance of reagent interference in pretransfusion testing using column agglutination at the Hospital of Southern Denmark, Aabenraa.

Case presentation: A 72-year-old male patient presented for pretransfusion testing prior to hernia surgery. He typed as O RhD negative without discrepancies, but the antibody screen showed weakly positive reactions. Routine investigations showed discrepancies, leading to further investigations.

Methods: Various serological tests were performed using in-house and commercial red test cells suspended in different suspension media and with different column agglutination cards and cassettes. Further investigations included washing of test cells, testing alternative saline solutions, varying incubation temperatures, testing without antihuman-globulin, and applying proteolytic enzymes.

Results: Reactivity was present with red cells suspended in ID-CellStab (BioRad) but not in Red Cell Diluent (Quidel-Ortho). Reactivity was abolished by using trypsin-treated cells, indicating either the presence of an antibody reacting with-or unspecific agglutination depending on-a trypsin-sensitive protein, in both cases enhanced by ID-CellStab.

Conclusion: This case highlights the importance of recognising reagent-dependent reactivity in serological testing. Adjustments to the suspension media resolved the incompatibility. Immunohematology laboratories should consider potential reagent interference when unexpected agglutination occurs.