Vox Sanguinis最新文献

Background and objectives: High-sensitivity assays for infectious screening of blood donations still occasionally result in false-positive test results (FPTRs). The cause of FPTRs is not always clear and may stem from both lot-dependent and lot-independent factors. FPTRs generate additional administration and extra costs for confirmatory testing and may cause concern among deferred donors.

Materials and methods: First-time and second-time FPTRs among blood donors screened from January 2021 to November 2023 were identified in the blood bank computer system. Abbott Alinity i hepatitis B surface antigen, hepatitis C virus (HCV) antibody and human immunodeficiency virus (HIV) antibody/antigen assays and Roche Cobas MPX assay were used for screening. Using logistic regression, we examined whether the risk of second-time FPTR was affected by being a new donor, sex, age and time between two donations.

Results: During the study period, 38,962 donors gave 223,323 donations. The total number of FPTRs was 216. Among the donors with a first-time FPTR, 83 had a second donation within the observation period, and 56 (67.5%) of these had a second-time FPTR. In total, 0.2% of donors were deferred because of second-time FPTR. New donors with a first-time FPTR had a significantly higher risk (adjusted odds ratio [aOR] = 6.06, 95% confidence interval [CI] [1.17-31.55]) of a second-time FPTR, which occurred in 89.5% of cases.

Conclusion: An increased risk of second-time FPTR was found among new donors, and hence it may be beneficial considering the donors' ethical and economical aspects, to defer this group of donors after the initial FPTR. Lot-independent factors might explain why some donors keep getting FPTR even after years.

Background and objectives: Transfusion-transmitted syphilis remains a concern, necessitating robust screening. This study evaluates the prevalence of syphilis among blood donors using electrochemiluminescence immunoassay (ECLIA), rapid diagnostic card test (RDT) and venereal disease research laboratory (VDRL) tests, comparing their diagnostic performance.

Materials and methods: A prospective observational study was conducted on 10,403 donors by ECLIA. Reactive samples underwent RDT and VDRL testing. Additionally, 100 ECLIA-negative controls were retested to assess test specificity as well as internal validation. Qualitative and quantitative VDRL testing were performed. Correlations between ECLIA cut-off index (COI) values and VDRL titres were analysed. Statistical analyses included descriptive statistics, Chi-square tests as well as receiver operating characteristic (ROC) curve and area under the curve (AUC) for each method.

Results: Syphilis prevalence was 1.05% (109/10,403) by ECLIA. Of these, 85% were RDT-reactive and 60.5% VDRL-reactive. All ECLIA-negative controls were non-reactive in RDT and VDRL. VDRL showed 83.3% sensitivity, 97.7% specificity and an AUC of 0.950. RDT demonstrated 97.8% sensitivity, 93.7% specificity and an AUC of 0.985. ECLIA COI values correlated strongly with VDRL titres (ρ = 0.822, p < 0.001). No significant association was found with gender or donor category.

Conclusion: ECLIA proved to be a reliable primary screening tool for syphilis because of its high sensitivity and strong correlation with VDRL titres. RDT showed superior diagnostic accuracy compared to VDRL, supporting its use as a supplementary method in resource-limited settings. These findings highlight the need for robust screening strategies to enhance transfusion safety.

Background and objectives: The Vel antigen is clinically significant and its alloantibody is involved in haemolytic transfusion reactions. This antigen has a high prevalence in the population. The Vel-negative phenotype is the result of a homozygous deletion in the SMIM1 gene (c.64_80del) and hinders the expression of the SMIM1 protein.

Materials and methods: A total of 17,472 blood donor samples from the Center for Hematology and Hemotherapy of Santa Catarina State were genotyped targeting the 17-nucleotide (c.64_80del) deletion in the SMIM1 gene. The same method was applied to the siblings of the donors identified as Vel-negative.

Results: The frequency of the c.64_80del17 deletion was 0.90%, and 0.03% of the donors were Vel-negative. In the family study, two individuals were identified as having the homozygous c.64_80del.

Conclusion: These findings underscore the relevance of identifying Vel-negative donors for enhancing rare donor registries and improving transfusion safety.

Background and objectives: Paediatric transfusion therapy is critical for managing haematological and genetic disorders. However, parental knowledge about transfusion risks, including transfusion-transmitted infections (TTIs) and adverse reactions, remains largely unexplored. This study assessed parental knowledge, attitudes and practices (KAP) regarding paediatric blood transfusions.

Materials and methods: A prospective cross-sectional study was conducted at a tertiary care children's hospital in India over 6 months. A structured questionnaire evaluated parental knowledge.

Results: Among 230 parents (51.7% mothers), 51.3% knew their child's ABO blood group and 76.1% correctly identified the required blood component. Awareness of TTIs screened in donated blood (25.9%) and leukoreduction (2%) was low. Parents of children on chronic transfusion therapy demonstrated significantly better knowledge (p = 0.001 for blood group, p < 0.001 for blood component). Education level strongly predicted transfusion-related knowledge: parents with high school education were 16.8 times more likely to know the blood group (odds ratio [OR] = 16.84, p < 0.001) and 10.4 times more likely to identify the correct blood component (OR = 10.44, p = 0.026).

Conclusion: Significant gaps exist in parental knowledge, particularly regarding TTIs and leukoreduction. Higher education and chronic transfusion exposure improve awareness. Graduate education was linked to a better understanding of TTIs (OR = 2.95, p = 0.038). Targeted education can enhance transfusion safety and the consent process.

Background and objectives: Bedside electronic transfusion checks (BETC) enhance transfusion safety by reducing errors associated with manual processes. Despite national recommendations, BETC adoption in the United Kingdom remains limited. This study reports on the implementation of BETC at four hospitals at Barts Health NHS Trust, aiming to share insights on the implementation process.

Materials and methods: The main implementation was split into three phases: (1) pre-pilot, (2) pilot and (3) main implementation (2022-2025). Staff surveys on training satisfaction and key performance indicators (KPIs) on transfusion activity were used to evaluate the uptake of the BETC system. Statistical process control (SPC) charts were used to identify trends, variation and patterns in the data following the implementation of BETC.

Results: A total of 5079 staff were trained and 404 personal digital assistant (PDA) devices deployed across four hospitals. Early implementation highlighted that training 60% of staff was insufficient for optimal system use, increasing this threshold to 80% improved adoption. BETC was initially more commonly used for blood administration than group and screen (G&S) sample labelling. Over time, increased usage of BETC for G&S labelling correlated with a marked reduction in sample rejection rates across all sites. Staff reported high satisfaction with training, with 99.5% rating it positively.

Conclusion: Early adopters played a pivotal role, but achieving widespread adoption required extended training and support. Addressing technical and workflow barriers, coupled with mandatory system use, could enhance the speed of impact of BETC. These insights offer guidance for future adopters aiming to improve transfusion safety and efficiency.

Background and objectives: Tranexamic acid (TXA) as an adjunct to prophylactic platelet transfusion is sometimes used to prevent bleeding in patients with malignancies experiencing chemotherapy-induced thrombocytopenia. However, there is little biological evidence in support. This pilot exploratory study aimed to evaluate the haemostatic efficacy of TXA before and after platelet transfusion versus platelet transfusion alone in patients with haematological malignancies experiencing chemotherapy-induced thrombocytopenia.

Materials and methods: Rotational thromboelastometry (ROTEM; EXTEM, tissue plasminogen activator [tPA]-EXTEM and FIBTEM) was used to assess the haemostatic effect of these treatments.

Results: Eighteen patients were randomized to receive platelet transfusion and either 3 or 1.5 g of TXA per day or to be observed. At enrolment, ROTEM parameters were similar across groups. TXA alone did not affect EXTEM clot formation time (CFT) or maximum clot firmness (MCF). A trend towards increased EXTEM CFT and MCF values 2 h after platelet transfusion was observed. The effect of TXA was witnessed by the increase in tPA-EXTEM lysis index at 60 min (LI60). In the observation group, tPA-EXTEM LI60 also significantly increased after platelet transfusion. The World Health Organization (WHO) rates for grade ≥2 bleeding and the median number of platelet transfusions were similar across all groups.

Conclusion: Platelet transfusion as well as TXA decreased fibrinolysis for this patient population. This could be explained by the plasminogen activator inhibitor 1 contained in platelets. Future research should explore other alternative treatments and the utility of viscoelastometric testing to guide platelet transfusions, particularly in cases of bleeding or platelet transfusion refractoriness.

Tranexamic acid (TXA) is an essential life-saving medicine that prevents clot breakdown in patients who are haemorrhaging from trauma, childbirth, surgery and other causes. While TXA is inexpensive, it is not widely used, especially in low- and middle-income countries, which also experience challenges in the domains of blood collection, testing, storage and transfusion. TXA has been extensively studied for the treatment of traumatic, obstetric and surgical bleeding, and landmark trials have repeatedly demonstrated its safety, efficacy and life-saving potential, especially when given early (within 3 h of the inciting event). Among trauma patients with blunt and penetrating injuries as well as head trauma, TXA decreases the risk of mortality and is also cost effective. Among women with postpartum haemorrhage, TXA decreases the risk of death due to bleeding, and has been successfully implemented as part of a bundled response. Among surgical patients across sub-specialties, TXA decreases the risk of mortality and even decreases the need for blood product transfusion. Furthermore, these trials have shown that TXA does not increase the risk of adverse events such as thrombosis or seizure. We encourage the global community to shift its focus from further trials to the development of standardized implementation protocols, which have been shown to increase TXA use in both high- and low-resource settings. Expansion of TXA availability and use in global blood deserts will help bridge the gap for haemorrhaging patients who are at risk of death and disability from injury, childbirth or surgical bleeding.

Background and objectives: The presence of warm autoantibodies (WAAs) complicates pre-transfusion and compatibility testing. Despite attempts to provide antigen-matched red blood cells (RBCs), the risk of alloimmunization remains. Rates of alloimmunization and indications for transfusion were reviewed to streamline testing and RBC provision algorithms at a large tertiary care centre serving patients with lymphoid cancers and complex surgical needs.

Materials and methods: This retrospective observational study investigated the development of new RBC alloantibodies in patients with WAAs. This included 295,109 antibody screenings and 3129 antibody investigations (AIs) performed on 2493 patients between 1 September 2019 and 30 June 2024. AI results for patients with a history of WAAs were reviewed, along with diagnoses, transfusion data, and where applicable, phenotyping and genotyping results.

Results: Ninety-four patients had WAAs. Twenty-three of them (24%) had lymphoproliferative disorders (LPDs) and 21 (22%) required urgent antibody tests for surgical procedures. Fifty-one patients (54%) received RBC transfusions, and 30 of them (59%) had anaemia with haemoglobin below 70 g/dL. Thirteen patients (14%) required RBC genotyping because of recent transfusions or indeterminate results. The alloimmunization rate was 10%, including anti-Jk^a, anti-Kp^a, anti-Jk^b, anti-C^w, anti-Js^a and anti-Le^a, after RHDCE/K or more extended-matched RBC transfusions.

Conclusion: RBC alloantibodies develop in patients with WAAs, as the urgency of transfusions often limits the complete identification of antibodies and extended phenotype matching. With prompt investigation and RBC preparation, the risk of alloimmunization to major antibodies can be minimized.

Background and objectives: This study presents the results and experiences of bacterial testing of blood components (BCs) at the Croatian Institute of Transfusion Medicine during the period 2011-2024.

Materials and methods: During the 14-year period, 74,283 BCs were tested. Among these, 20,231 components (8345 red blood cell concentrates, 5729 platelet concentrates [PCs] and 6157 plasma units) were tested as part of statistical quality control (QC). In addition, 100% bacterial screening was implemented for aphaeresis platelets in November 2019 and for pooled platelets in October 2022 with 17,187 aphaeresis platelets and 36,865 pooled platelets tested by the end of 2024. All pooled platelets were tested using the large-volume delayed sampling (LVDS) method, whereas 9596 aphaeresis platelets were tested using the two-step method (from November 2019 to November 2022) and 7591 using LVDS (from November 2022 to December 2024). BCs were sampled and inoculated into both aerobic and anaerobic culture bottles and incubated at 36 ± 1°C for 7 days.

Results: As part of the statistical QC, 20,231 BCs (5729 PCs) were tested, resulting in a confirmed contamination rate of 0.09% (0.14% for PCs). Since the implementation of universal screening, 54,052 PCs have been examined, with a confirmed positivity rate of 0.18%. The most frequently detected organism was Cutibacterium acnes.

Conclusion: The confirmed positive rate of bacterial testing in our study and the isolates from positive cultures are comparable to similar studies. Active bacterial screening of BCs, among other measures, remains a critical step for preventing transfusion-associated bacterial infections.

Background and objectives: Non-invasive foetal RHD (fRHD) genotyping is widely implemented to prevent unnecessary administration of antenatal anti-D prophylaxis. Reliable assay performance is critical. In line with expert recommendations, we validated and implemented an artificial spike-in extraction control in our previously published assay. In this study, we report on assay verification and its performance in a 2-year cohort.

Study design and methods: fRHD typing was performed with cell-free DNA isolated from maternal plasma from gestational age week 27 or later. A circular plasmid with a fragment of glycoprotein B gene of the Phocid herpes virus type 1 (PhHV1-gB) (spike-in control) was added to the plasma before DNA extraction. Assay accuracy was verified with gestational week-27 plasma samples and corresponding cord blood samples from D-negative pregnant women. In addition, assay performance over time was evaluated in a 2-year cohort.

Results: The performance verification of our modified assay showed no false negative and one false positive test result in a small clinical cohort (n = 191). In a further 47,391 samples across 1111 runs, we observed eight false negative results due to technical failures that were prevented by the addition of the spike-in control. In this larger series, the spike-in control was the sole detector of a technical problem most likely related to different batches of the DNA extraction kit.

Conclusion: This study demonstrates the prevention of false negative fRHD typing results by the addition of an artificial extraction control. This control allows improved monitoring of assay performance, thereby ensuring assay consistency. Findings underscore the importance of thorough quality assurance measures in fRHD genotyping.