Transfusion Medicine最新文献

Background: Haemoglobin plays a crucial role in oxygen transport, and any acute deviation will trigger compensatory hemodynamic functions. While the consequences of anaemia are well documented, the effects of haemoglobin reduction in individuals without anaemia remain less explored. Patients with polycythaemia vera and healthy blood donors, who both undergo regular phlebotomies, offer a valuable model for studying these effects.

Methods: This observational case-crossover study assessed short-term physiological and quality-of-life changes following phlebotomy in five patients with polycythaemia vera and six healthy blood donors. Participants were remotely monitored using a smartwatch and completed daily quality-of-life assessments. The primary outcome was heart rate, while secondary outcomes included step count and quality-of-life measures.

Results: Patients with polycythaemia vera exhibited stable heart rates, with only minor variations in physical activity and quality of life after phlebotomy. In contrast, healthy blood donors experienced a significant increase in heart rate, which returned to baseline within a week. Physical activity remained clinically unchanged in both groups, and quality-of-life scores were stable.

Conclusions: This pilot study demonstrates that any acute haemoglobin reduction, even within the normal range, induces measurable heart rate changes that are directly related to probably the most optimal oxygen delivery state. Moreover, our studies show that wearable technology is sensitive enough to detect these effects. Hence, this nowadays readily available telemetry allows monitoring of subtle physiological changes in a research setting, but it also offers a path towards optimising QoL for patients with anaemia, polyglobulia and for blood donors.

Background: The H antigen, precursor of the A and B blood groups, is a high-prevalence antigen. Very few H antigen-negative (H-) blood donors are available in the United Kingdom.

Case presentation: We present the case of a second pregnancy in a 28-year-old woman with the very rare AB_h phenotype, and the presence of anti-H, anti-A and anti-B. Only H- (O_h) and AB_h phenotype red cells were compatible. Given the rarity of individuals with these phenotypes, there were insufficient compatible red cell units for management of a major antepartum or postpartum haemorrhage. For this high-risk pregnancy, meticulous multidisciplinary team (MDT) planning took place between haematologists, obstetricians, anaesthetists, hospital laboratory staff and multiple teams within National Health Service Blood and Transplant including the National Frozen Blood Bank, Rare Donor Team and Red Cell Immunohaematology Laboratories. The MDT produced a birth management plan for various eventualities where blood transfusion may have been required. This process included the creation of our hospital's first vaginal cell salvage policy. A successful routine vaginal delivery was managed without transfusion.

Conclusion: This case highlights the optimal care of a woman with an extremely rare blood group in pregnancy. The principles of management described here are also more widely applicable to women in whom transfusion is contraindicated, undeliverable or declined for other reasons.

Background: An NGS-based assay was developed to determine the presence or absence of paternally inherited genetic variants in cfDNA derived from the fetus in the plasma of pregnant women. This assay can be used in connection with NGS-based prenatal prediction of fetal blood groups in immunised pregnant women. The purpose of the assay is to minimise the risk of a false-negative outcome in the situation with a prediction of the absence of a blood group allele from the fetus.

Methods: The underlying principle was to examine genetic markers, with each single marker giving a small contribution to the probability of differentiating between individuals (woman and fetus) and combining several markers into one multiplex PCR assay with enough discerning power to determine whether cfDNA from a fetus was present in maternal plasma. If only maternal cfDNA was detected, a prediction of the absence of a fetal blood group might be due to a false-negative result based on insufficient amounts of fetal cfDNA.

Results: The assay did not require knowledge of maternal or paternal genotypes. The genetic markers were deletion or insertion variants and were selected using an SQL algorithm searching all autosomes from gnomAD v 3 on the Google Cloud Platform and included alleles with a frequency close to 0.5 in four different ethnic populations, including several other criteria. The final assay consisted of a multiplex PCR amplification of 22 different biallelic delin markers, each located on a separate chromosome. The assay is informative in >99% of cases with at least one primer set. After experimental testing, an algorithm for scoring test results was defined, and the cut-off was set at <0.15%.

Conclusion: Per sample, the control assay required one extra dedicated multiplex PCR, which was eventually spiked into the sequencing reaction. The assay estimated the presence of non-self-genetic variation and may have applications beyond control for the presence of fetal cfDNA.

Background: Hospital de Clínicas, in conjunction with the Universidad de la República UDELAR in Uruguay, evaluated the quality of blood components after separation with a top-and-bottom (TB) system, comparing it with the top-and-top (TT) system and verifying compliance with local and international standards.

Study design and methods: Whole blood (WB) was collected using TB (n = 150) and TT (n = 130). TB units were processed with MacoPress Smart, obtaining red cell concentrate (RCC), plasma (PL), and buffy coat (BC). After 2 h, BC had a soft spin centrifugation for a single unit of platelet concentrate (SUPC). TT bags were managed on day 0 (up to 8 h of collection) with manual press obtaining RCC and platelet-rich plasma units (PRP). PRP had hard spin centrifugation and was separated again with the manual press to collect PL and SUPC.

Results: TB system produced RCC with higher haemoglobin concentration and Haematocrit but with lower volume and Hb/unit (p < 0.001). The TB system produced RCC with lower leukocytes and residual platelet levels (p < 0.001). SUPC showed fewer residual leukocytes and red cell levels with TB (p < 0.001), but TT produced a higher mean platelet count than the TB system (p < 0.001). During this evaluation, there was no significant difference in the mean plasma volume (p = 0.178).

Conclusion: The analysis favors the implementation of TB in the HC Blood Bank, improving the quality and safety of the transfusion service.

Introduction: Zika virus (ZIKV) is primarily transmitted through the bite of the Aedes aegypti mosquito, though transmission via blood transfusion has also been documented. During the 2015 ZIKV epidemic in Brazil, severe complications were observed in pregnant women, leading to fetal microcephaly. This study evaluated the persistence of ZIKV in blood donated by healthy individuals during the post-epidemic period from 2016 to 2020.

Methods: Blood donor samples from 109 296 individuals were screened for ZIKV RNA using nucleic acids extracted from plasma pools (six donors per pool). These samples had previously undergone routine nucleic acid testing (NAT) for HBV, HCV and HIV.

Results: Viral RNA (Ribonucleic Acid) was detected in a donor sample from the city of Santos in May 2016, resulting in a prevalence of 0.0009%. The positive donor was confirmed through viral sequencing using the Sanger method. Sequencing and phylogenetic analysis of an envelope gene amplicon revealed that the Zika virus RNA detected belonged to the Asian clade. This Asian lineage strain emerged in Brazil, Fortaleza, in 2015, isolated in northeastern Brazil in 2015, an area where most cases of microcephaly associated with ZIKV have been reported. A follow-up sample collected 1 month after donation showed seroconversion.

Conclusion: The detection of ZIKV RNA by NAT in a donated blood sample demonstrates that, although extremely rare, the virus is still present. Periodic active surveillance of blood donations for viruses associated with past outbreaks may help identify an incipient resurgence before it develops into a new epidemic.

Background: Transfusions of packed red blood cells (RBC) have long been used to correct postpartum anaemia. Given the ongoing shortage of packed RBC and transfusion reactions, we sought to determine if the use of IV iron sucrose infusions could decrease transfusions in the postpartum period.

Methods: We conducted a six-year quasi-experimental interrupted time series study from January 2016 to December 2021. The study was divided into three phases: 1. pre-intervention phase, 2. roll-out phase, and 3. post-intervention phase. Our intervention focused on a holistic transfusion prevention bundle that incorporated provider education regarding transfusion practices, antepartum optimization, and cell saver use. The main outcome was change over time from the use of IV iron sucrose over allogenic blood products in the setting of postpartum anaemia. Statistical process control (SPC) was used to explore the effect of our bundled intervention over time.

Results: 46 478 deliveries were recorded. The XmR control chart showed a shift between phases 1 and 3, as indicated with a special cause signal. The U control chart demonstrated that IV iron infusions increased from 5.6 per 1000 births in phase 1 to 136.4 per 1000 births in phase 3. On Poisson regression, the rate of IV iron sucrose infusions increased 19-fold [RI 19.65 (95% CI 16.00-24.14 p < 0.0001)], while the rate of transfusions decreased by 60% [RI 0.4 (95% CI 0.33-0.49 p < 0.001)] from pre- to post-intervention.

Conclusion: A holistic transfusion prevention bundle was associated with both a reduction in the number of patients transfused and the rate of multiple-unit RBC transfusions.

Objectives: The study aimed to analyse transfusion practices in sensitised autoimmune haemolytic anaemia (AIHA) patients and transfusion outcomes following transfusion of antigen-matched best-matched (AMBM) red cells.

Background: Transfusion practices in AIHA patients across resource-poor settings remain a challenge. The outcome of transfusions following the practice of transfusing best-matched (BM) units remains unknown. The data on alloimmunisation rates in sensitised AIHA patients, the utility of adsorption, and transfusion of AMBM red cells from resource-poor settings will enhance the adoption of optimal practices.

Methods and materials: Retrospective data on AIHA patients' work-up were collected and analysed for a 5-year interval. Patients were grouped based on the presence or absence of alloimmunisation and whether they received transfusion of AMBM versus BM units based on serological testing. Inter-transfusion interval (ITI) and post-transfusion haemoglobin increment (PTHI) were calculated and compared.

Results: Of 368 AIHA patients during the study period, adsorption was performed in 138 patients with a history of a sensitising event. Red cell alloantibodies were identified in 74 patients (53.6%). Shorter ITI was observed in alloimmunised patients when transfused BM red cells versus AMBM red cells [2 (1-3) days vs. 4 (3-5) days; p < 0.001]. Lower PTHI was observed in alloimmunised patients when transfused BM red cells versus AMBM red cells [0.65 (0.45-0.8) g/dl vs. 0.9 (0.7-1.2) g/dL; p < 0.001].

Conclusion: High alloimmunisation rates were observed in sensitised AIHA patients. Significantly higher PTHI and longer ITI were observed with transfusion of AMBM units. These findings highlight the benefits of identifying and matching against alloantibodies for better transfusion outcomes.

Objectives: Rapid and accurate identification of blood groups is the foundation of emergency blood support. We performed a complete assessment of a new solid-phase kit for ABO forward grouping and RhD grouping (ABD Kit, InTec Products, Xiamen, China) on the analytical performance, which was compared with those of traditional methods.

Methods: We analysed 1260 clinical samples using the ABD Kit, including weakly agglutinated samples of A, B and D antigen, and compared the test results with those via Gel card, test tube and slide methods. We also validated the results of typing blood samples containing weak antigens using first-generation gene sequencing.

Results: The ABO forward group and RhD group of 1260 samples was determined using ABD Kit, revealing that the inter-batch repeatability rate of the kit was 100%. The results of the kit were compared with those of the gel card method, revealing that the detection accuracy of the kit was also 100%, which was confirmed by comparing the detection of weak antigen samples with the results of first-generation gene sequencing. The accuracy of the test tube agglutination method was 100%. In contrast, the accuracy of the slide agglutination method was low, especially in the detection of weak A blood antigens (agglutination strength 1+), weak B blood antigens (agglutination strength 1+) and weak D blood antigens (agglutination strength 1+ or 2+).

Conclusions: The ABD Kit (InTec Products, Xiamen, China) showed high sensitivity, reproducibility and specificity, indicative of excellent analytical performance. It is a reliable, practical and promising solution for rapid and accurate identification of blood types.

Background and objectives: There is limited knowledge regarding cefamandole-related drug-induced immune haemolytic anaemia (DIIHA). We conducted a comprehensive serological and clinical follow-up study of a case of cefamandole-induced DIIHA to improve understanding of this condition.

Materials and methods: A patient with advanced hepatocellular carcinoma developed severe haemolytic anaemia along with significant worsening of hepatic and renal function after intravenous cefamandole was administered for a urinary tract infection. Serological testing included the direct antiglobulin tests (DATs), irregular red blood cell (RBC) antibody screening and detection of cefamandole-dependent antibodies using two standard methods for drug-dependent antibodies: 'testing in the presence of soluble drug' and 'testing drug-treated RBCs', which were performed after cefamandole discontinuation. Clinical follow-up was conducted for 41 days after drug cessation.

Results: The results of DAT for anti-IgG and anti-C3d were strongly positive, while irregular RBC antibody screening was negative. Plasma samples collected at different points from 13 to 38 days after cefamandole discontinuation were incubated with cefamandole-coated RBCs at 37°C, revealing both IgM and IgG cefamandole-dependent antibodies, with a maximum titre of 16. Following treatment with blood transfusion, intravenous immunoglobulin (IVIG), and methylprednisolone, anaemia and organ dysfunction showed marked improvement. Therefore, the patient was diagnosed with cefamandole-induced DIIHA.

Conclusions: This study may be the second serological analysis and the first comprehensive clinical follow-up of cefamandole-induced DIIHA. It demonstrates that cefamandole-dependent antibodies can activate complement, leading to severe haemolytic anaemia and hepatic and renal impairment. The 'testing drug-treated RBCs' method is suitable for detecting cefamandole-dependent antibodies.

Background: Blood centres, as part of their routine operations, generate various forms of waste during the collection-to-transfusion continuum. However, not all discarded blood components equate to 'wastage'.

Methods: A critical technical appraisal distinguishing blood discard (necessary and regulatory-compliant) from blood wastage (preventable and avoidable) was done.

Results: We propose clear operational definitions and introduce refined metrics such as blood discard rate (BDR), blood wastage rate (BWR) and total discard rate (TDR) to ensure accurate reporting. The concept of 'all-cause blood discard' encompassing both justified discards and true wastage is emphasised.

Conclusion: Misinterpretation of data on discarding as wastage by technical personnel, policymakers, media and the public at large can lead to a trust deficit in transfusion services. Adoption of these distinctions and metrics will improve transparency, resource management and public confidence in blood services.