Transfusion

Preoperative anaemia is common in adults undergoing cardiac surgery and may identify patients at increased perioperative risk. This systematic review and meta-analysis synthesised contemporary observational evidence in accordance with PRISMA 2020. Five databases were searched for peer-reviewed English language studies published from 2017 to July 2026. Random effects meta-analyses used restricted maximum likelihood estimation with Hartung-Knapp confidence intervals; crude exact count estimates were synthesised primarily and adjusted estimates separately. Fourteen observational cohort studies involving 74,571 adults, including 17,349 (23.3%) with anaemia, were included. Preoperative anaemia was associated with red cell transfusion (OR, 3.66; 95% CI, 2.14-6.24), acute kidney injury or renal failure (OR, 2.43; 95% CI, 1.84-3.21), early mortality (OR, 2.11; 95% CI, 1.40-3.17), and postoperative infection (OR, 1.49; 95% CI, 1.21-1.82), but not postoperative stroke (OR, 1.16; 95% CI, 0.43-3.17). Certainty was low for renal outcomes and very low for the other outcomes. Preoperative anaemia is an important perioperative risk marker, particularly for transfusion and renal complications, although causality cannot be established.

Quantitative measurement of fetal hemoglobin (HbF) using high-performance liquid chromatography (HPLC) is standard but expensive and widely unavailable in low-income settings. The newer Gazelle method, which employs single-use alkaline electrophoresis cartridges, provides a portable and relatively inexpensive potential alternative. In the current study, we tested 3055 venous blood samples collected from 1780 children with sickle cell anemia who were enrolled into the H-PRIME trial by both Gazelle and the Bio-Rad D-10 HPLC instrument, before and during hydroxyurea treatment. Data reinterpretation was required to quantify accurately high HbF values derived using the D-10. Mean (standard deviation) baseline HbF values by HPLC and Gazelle (N=2042) were 11.4% (SD 5.9%) versus 16.3% (SD 7.5%), respectively, while mean on-treatment HbF values (N=1013) were 18.9% (SD 9.0%) versus 25.4% (SD 11.5%), respectively. While overall agreement was good (Lins concordance 0.76, 95% CI 0.75-0.78), HbF values derived using Gazelle were modestly higher than HPLC values (Bland-Altman agreement mean +5.4%, 95%CI -2.4% to +13.2%), with the difference between measures increasing at higher HbF percentages. With strong concordance and more easily interpretable HbF values, Gazelle represents an attractive and inexpensive alternative to HPLC for HbF quantification in the low-income settings where most patients with sickle cell anemia live.

Platelet-leukocyte aggregates (PLAs) are a proposed interface between coagulation and immune regulation, but their distribution across leukocyte subsets beyond monocytes and neutrophils, and their behavior in acute disorders of immune regulation, such as sepsis and severe trauma, remain largely undefined. The study of thromboimmune mechanisms in these acute conditions has relied heavily on murine sepsis models, whose species differences in platelet and leukocyte biology limit translation to human disease. Direct measurement in human whole blood is needed yet reported PLA frequencies vary widely because quantification is highly sensitive to sample handling. Here we present a robust, minimally manipulative 27-color spectral flow cytometry protocol that allows simultaneous deep immunophenotyping and classification of PLAs across >40 leukocyte subpopulations. In healthy donors, PLA frequency ranged from 1.7% on memory CD4 T cells to over 50% on monocyte subsets, with monocytes contributing 25% of all PLAs. We also found novel platelet-binding leukocyte populations, including Th9 and Th22 CD4+ T cells. Optimization identified anticoagulant choice, centrifugation conditions, dilution, and sample processing time as key determinants of reproducible measurement; PLA quantification was validated by imaging flow cytometry. In a small validation cohort of sepsis and trauma patients, the assay recapitulated established immunophenotypic features of critical illness, including neutrophilia and myeloid-derived suppressor cells (MDSC) expansion, and quantified PLAs within each subset. This protocol provides a reference framework for studying thromboinflammation and other dysregulated immune response diseases directly in human blood, and a foundation for further studies, defining the mechanisms and clinical relevance of platelet-leukocyte interactions in disease.

Background: Erythritol and xylitol, naturally present in fruits and vegetables, are widely used as alternative sweeteners with minimal glycemic and insulinemic effects. Both are also produced endogenously, with elevated plasma concentrations reported in metabolic disorders and cardiovascular disease. Recently, two interventional studies reported enhanced platelet aggregation after acute oral intake of erythritol or xylitol, raising concerns about potential prothrombotic effects. We investigated whether acute exposure to erythritol or xylitol increases platelet reactivity in healthy individuals. Methods: We conducted a randomized, single-blind, crossover study in 14 healthy participants who received erythritol (50 g), xylitol (33.5 g), or water. Platelet aggregation was assessed ex vivo, together with circulating markers of platelet activation (P-selectin), endothelial activation (sVCAM-1), and coagulation (D-dimer), as well as plasma erythritol and xylitol concentrations. Complementary in vitro experiments were performed using platelet-rich plasma from 11 healthy participants exposed to increasing concentrations of erythritol or xylitol, followed by assessment of platelet aggregation. Results: Despite substantial increases in circulating erythritol and xylitol concentrations following oral intake, neither erythritol nor xylitol increased ex vivo platelet aggregation compared with water. Consistently, no relevant changes were observed in P-selectin, sVCAM-1, or D-dimer concentrations. Direct in vitro exposure of platelet-rich plasma to increasing concentrations of erythritol or xylitol likewise did not enhance platelet aggregation. Conclusions: In healthy individuals, acute oral intake of erythritol or xylitol did not increase platelet aggregation or circulating markers of platelet activation, endothelial activation, or coagulation. These findings were supported by in vitro experiments showing no direct effect of erythritol or xylitol on platelet aggregation. Our results do not support an acute platelet-activating effect of erythritol or xylitol under the conditions studied. Registration: URL: https://clinicaltrials.gov/study/NCT04966299; Unique identifier: NCT04966299.

Introduction: Hospitals face increasing financial pressures. Hospital reimbursement is tied to the Case Mix Index (CMI). The CMI is a measure of complexity of care provided by the hospital and the total reimbursement is the CMI multiplied by a base pay factor, multiplied by the total number of discharges from the hospital. The few studies in the literature have involved logistically complex attempts to improve documentation. We sought to determine whether limited, structured chart review by surgeons can improve CMI in a multihospital system. Methods: We performed a prospective, observational study in a four-hospital academic medical system on all surgical patients from 10/2022 to 7/2026. Two clinically busy trauma surgeons performed limited structured chart reviews for select surgical patients. In the limited intervention period (1/2024-9/2024) this focused only on the trauma division. In the full intervention period (10/2024-7/2026) expanded to all surgical patients across the system. The main outcome was surgical case mix index (CMI). Results: A total of 35,695 patients were included (13,811 pre-intervention, 9,337 limited intervention, 12,547 full intervention). CMI increased significantly among surgical patients across the whole system (2.68 (95%CI 2.65-2.71) to 2.87 (95%CI 2.82-2.92) to 2.97 (95%CI 2.93-3.01), ANOVA p <0.001). Overall length of stay was unchanged among surgical patients across the whole system. The estimated increase in revenue per patient attributable to this intervention was $3,912 in surgical patients across the system. Conclusion: Having trauma surgeons review targeted surgical patients for high value documentation capture significantly enhanced the CMI and estimated revenue of surgical services across a multi-hospital integrated health system. Such documentation reviews may represent a practical method to improve hospital documentation and revenue.

Objective: Rare STAB2 loss-of-function variants emerged in population studies as being associated with elevated venous thromboembolism (VTE) risk. STAB2 encodes the cell-surface scavenger receptor stabilin-2, and reduced stabilin-2 function might increase VTE risk via elevated plasma levels of its ligands, including von Willebrand factor (VWF) and coagulation factor VIII (FVIII). Approach and Results: A 13-year-old patient with dependency on parenteral nutrition had experienced episodes of central venous catheter-related thrombosis, including the complete thrombotic occlusion of the deep pelvic veins, and pulmonary embolism. Exome sequencing for increased VTE risk identified a homozygous STAB2 splice-site variant and its effect on splicing was characterized in fibroblast-derived RNA and in a minigene splicing system. Plasma VWF, FVIII, and fibrinogen and serum hyaluronic acid (HA) levels were determined. Immunohistochemistry was performed on liver biopsy tissue. The STAB2 splice-site variant caused aberrant STAB2 mRNA splicing. The patient's healthy mother and one healthy sibling were also homozygous for the STAB2 splice-site variant but had no history of VTE. Plasma FVIII levels and VWF activity were elevated in all three, and VWF antigen was elevated in two homozygous individuals. Strikingly, approximately 1000-fold elevated HA levels were observed in all three homozygous individuals. Stabilin-2 immunohistochemistry on a liver biopsy from the proband's mother revealed no detectable signal, whereas control human liver showed strong labelling of liver sinusoidal endothelial cells. The STAB2 splice-site variant thus results in loss of detectable stabilin-2 protein. Conclusion: To current knowledge, this is the first family-based report of stabilin-2 deficiency with markedly elevated circulating HA, VWF, and FVIII levels in humans. These findings support impaired stabilin-2-dependent ligand clearance as a thrombosis susceptibility state with incomplete penetrance. The data are consistent with a significant role for stabilin-2 in circulating HA clearance in humans, but do not establish elevated HA itself as a cause of VTE.

BACKGROUND: The protein 4.1a/4.1b ratio is an intrinsic molecular marker of mean red blood cell (RBC) age resulting from progressive deamidation of protein 4.1b during RBC circulation. Despite its potential for estimating mean RBC age from a single blood sample, its application has been limited by labor-intensive RBC membrane preparation, and its interindividual variability has not been characterized in a large human population. METHODS: We developed a low-volume method for direct RBC membrane isolation from whole blood using saponin permeabilization and differential centrifugation without prior RBC washing. Membrane proteins were separated by SDS-PAGE, and protein 4.1a/4.1b ratios were determined by densitometric analysis with Gaussian peak fitting. Assay conditions, sample-volume requirements, membrane protein recovery, and analytical reproducibility were evaluated. The method was subsequently applied to 114 anonymized residual samples from routine diagnostic testing selected for complete blood count parameters within the corresponding laboratory reference intervals. RESULTS: The optimized procedure used 50 uL of whole blood, 0.06% saponin, and centrifugation at 9000 g, although protein 4.1a/4.1b remained measurable from starting volumes as low as 5 uL. Mean within-subject CVs were 3.90% for electrophoretic/densitometric determination and 5.39% for membrane protein recovery; whole-procedure CVs in 3 subjects were 1.40% to 3.50%. In the population analysis, the mean protein 4.1a/4.1b ratio was 1.428 (SD 0.146), with an observed range of 1.052 to1.799 and a central 95% interval of 1.151 to 1.695. Ratios did not differ significantly between females and males (P=0.246) or among females aged 18 to 50 years, females aged >50 years, and males (P=0.151). The ratio showed modest positive correlations with chronological age in females (Spearman p=0.26, P=0.047) and males (p=0.33, P=0.015), while substantial interindividual variability remained across the age range. CONCLUSIONS: Direct isolation of RBC membranes from small volumes of whole blood enables reproducible determination of the protein 4.1a/4.1b ratio using a simplified workflow. Application of the assay to a comparatively large human population revealed substantial interindividual variation in this molecular marker of mean RBC age that was not explained by sex or chronological age alone. The method provides a practical approach for investigating biological variation in mean RBC age and its potential contribution to laboratory measurements influenced by RBC survival.

Abstract Background: Mean arterial pressure (MAP) is pharmacologically augmented in selected perioperative and critical care settings, including acute neurological conditions and after cardiac arrest, with the aim of improving cerebral perfusion, although it remains uncertain whether higher arterial pressure translates into increased cerebral blood flow (CBF). We investigated the CBF response to MAP augmentation with norepinephrine (NE), a commonly used vasopressor in perioperative and critical care settings, during propofol-based general anesthesia. Methods: In this prospective within-subject interventional study, 16 neurologically intact patients with ASA physical status I-II undergoing elective surgery were studied using phase-contrast magnetic resonance imaging. CBF was quantified in the awake state and during propofol-based general anesthesia before and after NE-induced MAP augmentation. During general anesthesia, NE was titrated to increase MAP by approximately 25% from baseline. Concurrent systemic hemodynamics were assessed. Results: General anesthesia was associated with a 50.1% (interquartile range, 42.1?55.7%) reduction in CBF and a 24.2% (20.3-29.2%) reduction in MAP compared with the awake state (both P<0.001). During general anesthesia, NE-induced MAP augmentation increased MAP by 25.7% (21.9-32.0%; P<0.001), whereas CBF remained unchanged (P=1.000). Cardiac output remained unchanged (P=0.163), whereas systemic vascular resistance index and cerebrovascular resistance increased by 40.0% (28.7-45.2%) and 36.2% (17.7-42.8%), respectively (both P<0.001). Changes in CBF during MAP augmentation were not associated with concurrent changes in MAP, cardiac output, or systemic vascular resistance index. Conclusions: In neurologically intact patients undergoing propofol-based general anesthesia, clinically relevant NE-induced MAP augmentation did not increase CBF despite an approximately 50% lower CBF than in the awake state. These findings challenge the assumption that pharmacological elevation of an otherwise adequate MAP improves cerebral perfusion in this setting. While maintaining adequate arterial pressure remains essential, further MAP augmentation should not be assumed to increase CBF. Clinical Trial Registration: https://clinicaltrials.gov/study/NCT06855407; NCT06855407.

Background: Prone cardiopulmonary resuscitation (CPR) may be necessary when turning a prone patient supine would delay chest compressions. Although prone compressions can generate arterial pressures comparable with or greater than supine CPR, the pathway of pressure transmission is uncertain. We examined synchronized intrathoracic, intra-abdominal, and central arterial pressures in both supine and prone positions. Methods: Two thawed fresh-frozen adult cadavers underwent three, 2-minute mechanical CPR trials per position in a counterbalanced crossover sequence. Solid-state catheters recorded pleural, peritoneal, and central arterial pressures simultaneously. Trial-level outcomes included peak pressure, mean pressure, pressure-time area, and the mean peritoneal-to-pleural pressure gradient. Exploratory fixed-effects models included position, cadaver, and their interaction. Results: Prone CPR increased peak intrathoracic pressure by 7.04 mmHg, peak intra-abdominal pressure by 21.69 mmHg, and peak arterial pressure by 15.40 mmHg. Mean intra-abdominal and arterial pressures increased by 16.22 and 9.90 mmHg, respectively. The mean peritoneal-to-pleural gradient reversed direction from -8.46 mmHg supine to 4.85 mmHg prone. Intrathoracic pressure-time area increased 3.4-fold, from 1.62 to 5.46 mmHg{middle dot}s, and arterial pressure-time area increased 2.2-fold, from 2.96 to 6.42 mmHg{middle dot}s. Conclusions: Compared to supine, prone mechanical CPR generated higher arterial pressures and reversed the pressure relationship across the thoracoabdominal boundary in both cadavers. Higher abdominal pressure coincided with a larger intrathoracic pressure-time area, a pattern compatible with reduced caudal pressure dissipation.

Importance: Phosphorylated tau at threonine 217 (p-tau217) and brain-derived tau (BD-tau) are increasingly used as blood biomarkers of Alzheimer's disease (AD) and related neurological disorders. However, the distributions and biological correlates of elevated plasma p-tau217 and BD-tau in plasma from individuals eligible for blood donation remain unclear. Objective: To estimate the proportions of plasma p-tau217 and BD-tau exceeding exploratory study-specific thresholds, and examine associated inflammatory and transcriptomic features. Design: Cross-sectional study. Setting: Hospital blood bank. Participants: 257 de-identified donor samples were obtained between September 2025 and June 2026. Plasma samples from 30 population reference participants and 20 AD patients were used to derive study-specific thresholds. Complementary transcriptomic analyses were performed in 29 fresh whole blood samples. Main Outcomes and Measures: The primary outcome was the proportion of donor samples exceeding the study-specific ROC-derived Youden threshold. The proportion exceeding the prespecified published p-tau217 threshold was the secondary outcome. Other measures included plasma concentrations of BD-tau, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6); correlations among plasma p-tau217, BD-tau and inflammatory cytokines; and associated transcriptomic alterations. Results: Plasma p-tau217 concentrations exceeded the study-specific ROC-derived Youden threshold in 53 of 256 donor samples (21%; 95% CI, 16%-26%) and the published threshold, used for a secondary comparison, in 99 of 256 samples (39%; 95% CI, 33%-45%). Plasma BD-tau concentrations exceeded the study-specific threshold in 89 of 257 samples (35%; 95% CI, 29%-41%). Plasma p-tau217 concentrations were positively associated with plasma TNF-alpha (Kendall's tau = 0.339; P < .001) and IL-6 (Kendall's tau = 0.310; P < .001) concentrations. Exploratory transcriptomic analyses identified gene expression patterns associated with p-tau217 concentrations. Measurement using a second p-tau217 antibody showed the similar findings. Conclusions and Relevance: Plasma p-tau217 and BD-tau concentrations exceeded exploratory study-specific thresholds in a subset of blood-donor samples, and higher p-tau217 concentrations were associated with inflammatory biomarkers and exploratory transcriptomic differences. These findings raise the possibility of elevated circulating tau species in some blood donors, but their clinical significance requires confirmation. Whether elevated circulating p-tau217 in donated blood has biological consequences for transfusion recipients is unknown, but deserves investigation.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy, yet how donor alleles shape red blood cell (RBC) storage, transfusion performance, and recipient physiology remains unresolved. Across 13,091 donors, a recalled cohort, donor-recipient data, humanized mice, and a prospective sickle cell disease cohort, variants reduced G6PD abundance, constrained pentose phosphate pathway flux and redox metabolism, and accelerated age-dependent functional decay. Murine A-; RBCs recovered poorly; A-; and Mediterranean RBCs impaired renal oxygenation, especially the latter, which caused greater plasma hemolysis. In humans, A-; units yielded smaller hemoglobin increments, while deficient units reduced allogeneic 51Cr post-transfusion recovery and four-week survival by 8 and 12-percentage-points. NADP;-bound cryo-EM resolved mechanisms: remodeling of the catalytic NADP;-binding region and dimer interface underlies A-; kinetic fragility, whereas Mediterranean S188F exhibits temperature-dependent oligomerization and conformational instability. These findings define an allelic series linking genotype to molecular instability, RBC quality, transfusion performance, and recipient physiology.

Hospital readmission is used in cirrhosis research as if a return to hospital meant the disease had worsened: it is a trial outcome, a quality indicator and a prediction target. We asked what those readmissions were. Sixty-one adults with alcohol-related cirrhosis, selected because they had been hospitalized more than once, contributed all 326 later admissions to one department. A clinician read each full record and classified it for acute decompensation and for admission mode, blinded to diagnostic codes and structured flags. Fewer than two in five admissions (125, 38.3%) were decompensations. One in three (114) had been booked in advance; none of these was a decompensation, yet they used 29.1% of all bed-days. Among 124 returns within 30 days, planned admissions outnumbered decompensations, 48 to 43. Counting all admissions tracked a patients decompensations only moderately (correlation 0.50) whereas counting urgent admissions tracked them closely (0.93). In crude analysis the sicker patients had fewer admissions, not more, because planned care goes to those well enough to receive it. A liver severity score, computable for 165 admissions, did not separate planned from urgent admissions or decompensations from other stays, even within one patient. Readmission was not the same thing as decompensation.

Context: Cytological specimens allow minimally invasive, repeated sampling for diagnosis and molecular testing. However, cytology biobanking protocols have primarily been optimized for morphology, and the effects of preanalytical handling and storage on intracellular proteins remain unclear. Objective: To assess how fixation, staining, storage temperature, and duration affect intracellular protein preservation in cytological specimens and to identify conditions suitable for in situ proximity ligation assay (isPLA). Design: Human cancer cell lines were processed under different preanalytical conditions. Intracellular proteins and protein protein interactions were assessed by isPLA, fluorescence microscopy, and quantitative image analysis. Slides were stored at room temperature or minus 20 Celsius, with or without MayGrunwaldGiemsa (MGG) staining. Results: Storage temperature had the greatest effect on protein signal. Unstained slides stored at minus 20 Celsius retained strong signals for up to 24 months, whereas room temperature storage reduced detectable protein interactions by approximately 95%. MGG staining further reduced signal intensity during prolonged storage. Nevertheless, stained slides remained suitable for isPLA when staining, microscopic evaluation, destaining, and antibody labeling were completed on the same day. Prolonged room temperature storage of stained slides caused loss of antigenicity, increased autofluorescence, and false negative findings. Conclusions: Low temperature storage and standardized preanalytical handling preserve intracellular protein signals in cytological specimens. These conditions support reliable single cell protein profiling of archived samples and their use in biomarker research and translational pathology.

BackgroundEvaluating fairness in artificial intelligence (AI) is essential before clinical implementation to prevent unintended harm across diverse patient populations. This study assesses performance differences of an image-based surgical site infection (SSI) detection model across age, gender, geography, race, and skin color. MethodsModel development/validation study using retrospective, multicenter data across surgical subspecialties from adults who submitted an image of their incision via the electronic health record within 30 days of their procedure between 2019-2024. Area under receiver operating curve (AUROC) was compared by age (<55 vs. [&ge;]55 years old), gender (male vs. female), geography (Rochester, Minnesota vs. Jacksonville, Florida vs. Scottsdale, Arizona vs. regional Minnesota/Wisconsin areas), race (White/Caucasian vs. non-White/Caucasian), and skin color (Fitpatrick I-III vs. IV-VI and Monk A-E vs. F-J). ResultsTraining data contained 13,702 images from 4,274 patients between 2019-2022 (50.1% [&ge;]55 years old; 63.2% female; 91.6% White/Caucasian; 58.5% Rochester, 17.3% Florida, 10.5% Arizona; 96.3% light skin tone), of which 1,348 images (9.8%) had an SSI. No differences in SSI detection existed for age, gender, race, or skin color (AUROC 0.83-0.87, p>0.09), however geographical differences were significant: lowest AUROC 0.83 (95% CI 0.77-0.88) vs. highest AUROC 0.87 (95% CI 0.84-0.89, p=0.01). Temporal validation using 4,242 images from 1,353 patients between 2022-2023 showed intact fairness across subgroups ({Delta}AUROC [&le;]0.06) except geography ({Delta}AUROC [&le;]0.16). ConclusionsThe model behaved fairly across age, gender, race, and skin color, however geographical differences persisted. These findings have practical implications underscoring the importance of evaluating bias in clinical AI before deployment.

In resource-limited settings plasma is usually transported to centralized laboratories for HIV RNA quantification; often by motor vehicles using dry ice. Any decay in plasma HIV RNA when near the threshold used to define virologic failure could impact clinical management. However, maintaining a cold chain during transport can be costly and limit the frequency of shipments, which can delay clinical assessments and also negatively impact patient care. Transporting plasma at ambient temperatures could facilitate timely measurements of plasma HIV RNA viral loads (VL). We conducted a stability study of HIV RNA in plasma held for 1, 3, 5, and 7 days at a range of temperatures (4{degrees}C, 30{degrees}C, and 37{degrees}C) to simulate the durations and temperatures specimens could experience during transport. Thirteen large volume plasma specimens with VL ranging from 2.7-5.53 log10 copies/mL were evaluated. Mean changes in VL between Day-0 to Day-1, Day-3, Day-5 or Day-7 were calculated, with decays >0.5 log10 c/mL considered clinically relevant. Compared to Day 0, the VL of plasma stored at 4{degrees}C and 30{degrees}C remained stable across the Days tested. The VL in plasma stored at 37{degrees}C had a progressive decline at Day-1, Day-3, Day-5 and Day-7 (means of -0.04, -0.19, -0.33. -0.34 log10 c/mL, respectively), with a decay of >0.5 log10 observed in 3/13 (23%) specimens at Day-7. A linear regression analysis showed that plasma specimens stored at 37{degrees}C significantly decayed over time (slope -0.054, 95% CI -0.079, -0.029; p=0.01). Any decay observed among specimens stored at 4{degrees}C and 30{degrees}C was not clinically relevant nor statistically significant. Our observations suggest that HIV RNA levels in plasma should remain stable if transported to centralized laboratories at ambient temperatures of [&le;]30{degrees}C or chilled by cold packs over a period [&le;]7 days. Transporting specimens with cold packs instead of dry ice could reduce costs and facilitate the timely monitoring of VL used to assess and guide antiretroviral therapy.

Background Cardiac amyloidosis is an increasingly recognized cause of heart failure in older adults, yet Colombian data, and data from the southwest of the country in particular, remain scarce. We describe the clinical, diagnostic, imaging and outcome profile of patients with cardiac amyloidosis at two high-complexity institutions in Cali. Methods Observational, descriptive, retrospective, two-center study. Patients were identified in the institutional registries of both centers using ICD-10 codes for amyloidosis, and clinical data were abstracted manually from medical records. Continuous variables are reported as median (interquartile range) and categorical variables as counts and percentages over the number of patients with available data. Results Thirty-two patients were analyzed (median age 77 years; 68.8% men). Heart failure (90.6%), atrial fibrillation (46.9%) and carpal tunnel syndrome (31.2%) were frequent. The etiological classification depended on the test considered: bone scintigraphy was positive (Perugini 2-3) in 23 of 26 patients studied (88.5%), but a monoclonal protein was screened for in only 22, and the full non-invasive criteria for ATTR were met in 16 of 32 (50.0%). Genetic testing was positive in 9 of 18 tested, and the variant was Val142Ile in all 8 patients in whom it was characterized. The working diagnosis was ATTR in 26 patients (81.2%) and AL in 6 (18.8%). Tafamidis was used in 37.5%. Eleven of the 31 patients with known vital status died (35.5%), and NT-proBNP was markedly higher among those who died (6640 vs 1186 pg/mL; p=0.003). Conclusions In this southwestern Colombian cohort, cardiac amyloidosis presented as the classic transthyretin phenotype, with the Val142Ile variant in all 8 patients in whom it was characterized. Bone scintigraphy was frequently positive, but screening for a monoclonal protein was often omitted, so only half the cohort met the full non-invasive criteria for ATTR. Mortality was high and closely associated with NT-proBNP.

Background. Persistent SARS-CoV-2 antigen is a leading hypothesis for post-acute sequelae of SARS-CoV-2 infection (PASC), commonly known as Long COVID. Impaired Fc-mediated antiviral antibody function could contribute to inefficient clearance of infected cells and viral antigen despite preserved antibody levels. Therefore, we tested whether PASC is associated with altered Fc{gamma} receptor-mediated antibody function and differences in IgG1 Fc fucosylation, a major regulator of Fc effector function. Methods. Serum samples from RECOVER-Adult participants with prior SARS-CoV-2 infection (99 PASC, 139 non-PASC) were analyzed for anti-SARS-CoV-2 spike receptor-binding domain (RBD) IgG and subclasses, Fc{gamma}RIIIa- and Fc{gamma}RIIa-mediated reporter activity as surrogate measures of antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), anti-RBD IgG1 Fc glycosylation, and circulating fucose-modifying enzymes. Results. Despite higher anti-RBD IgG and IgG1 abundance, PASC sera showed lower ADCC- and ADCP-associated Fc{gamma}R reporter activity, including after normalization for antibody abundance. Anti-RBD IgG1 showed greater fucosylation in PASC samples (30 PASC, 34 non-PASC). Serum FUCA2 was lower in PASC samples (24 PASC, 34 non-PASC), whereas FUCA1 and soluble CD16a levels did not differ between the two groups. Conclusion. PASC is associated with impaired antiviral IgG Fc function, increased IgG1 Fc fucosylation, and reduced circulating FUCA2, identifying a glycoimmune axis that may contribute to impaired Fc-dependent antigen clearance and represents a potentially targetable pathway in Long COVID.

Background: Articulated laparoscopic instruments require a reliable mechanical connection between the handle and shaft to maintain the intended instrument configuration during surgical manipulation. The handle shaft locking interface should resist unintended relative displacement under external loading. However, the appropriateness of a specific slip resistance threshold must be evaluated in relation to the instrument design and intended conditions of use. Objective: To evaluate the mechanical performance associated with an 8 N slip resistance specification for the locked handle shaft interface of an articulated laparoscopic instrument using a controlled bench model. Methods: A bench based mechanical evaluation method was designed using the instrument under test, mechanical fixtures, a calibrated force measurement device, and displacement measurement equipment. After engagement of the handle shaft locking mechanism, external forces were applied to evaluate resistance to relative displacement. Testing included axial loading, loading in relevant transverse directions, and repeated locking unlocking cycles. The primary outcome was the force corresponding to the onset of relative slippage at the locked interface. Secondary outcomes included displacement under load, complete locking failure, and changes in mechanical performance after repeated operation. Acceptance criteria should be established before confirmatory testing. Results: All 30 instruments from three production batches met the 8 N axial requirement (30/30). The axial slip onset force was 12.40 N . Under a sustained load of 8 N for 60 s, mean relative displacement increased from 0.06 mm to 0.10 mm, and mean residual displacement was 0.02 mm. After 1,000 cycles, the axial slip-onset force was 12.00 N . Conclusions: This study provides a bench-testing framework for evaluating an 8 N slip resistance specification for the handle shaft locking interface of an articulated laparoscopic instrument. Whether this specification provides adequate mechanical stability can be determined only by comparing the measured performance with engineering acceptance criteria established in advance on the basis of the instrument's intended use and foreseeable loading conditions.

Background Chronic subdural hematoma (CSDH) is common and increasing in incidence. Short-term post-surgical outcomes are good, but longer term, patients experience increased morbidity and early mortality than controls and the general population. Deprivation and ethnicity affect many health conditions, but to our knowledge, this is the first UK study investigating their association with CSDH outcomes. Methods This single-centre retrospective cohort study used Secondary Uses Service Admitted Patient Care Spells (SUS+ APCS) data. Adult subdural hematoma (SDH) patients admitted to St Georges Hospital, London treated with burr-hole surgery between April 2022 and April 2025 were included. Primary outcomes were initial length of stay (LoS) and days spent hospitalised in the subsequent year. Deprivation was measured using Index of Multiple Deprivation (IMD). Linear regression models estimated initial LoS and subsequent days spent hospitalised by category, adjusted for factors including age, ethnicity and comorbidities. Results In this single-centre cohort of 449 patients, IMD was not associated with initial LoS, but was significantly associated with subsequent time spent hospitalised. In a log-transformed linear regression model, the most deprived spent 4.5-times longer hospitalised during the year after CSDH than the least deprived (fold change = 4.45, 95% confidence interval (95%CI) 2.20 to 9.01). Conclusions Higher neighbourhood-level deprivation was associated with time spent hospitalised following CSDH. This was robust to adjustment for potential mediating factors. This is the first UK study demonstrating health inequalities in CSDH outcomes, highlighting a need for future research to gain further insights, and to improve equity of outcomes after CSDH.

The human T cell repertoire is generated through recombination of a multitude of T cell receptor gene segments, yielding a complex array of T cell clones. T cell receptor beta (TRB) V gene segment defined, T cell clonal frequency when organized in correspondence with the respective V gene segment positions on the TRB genomic locus yields a periodic, undulating curve in the spatial domain. Using the genomic distance from the TRB-D1 segment to the TRB-V1-29 segments, spectral analysis was performed utilizing Lomb-Scargle periodogram (modified Fourier analysis) to obtain spectral power curves quantifying the TRB V clonal frequencies from 12 allogeneic stem cell transplant donors (baseline) and recipients (<100 days or b/w 100-365) using a variety of analytic software. Patients either underwent HLA matched related bone marrow or HLA matched unrelated blood stem cell transplantation, using PT-CY for the former and ATG for the latter. Spectral Power curves revealed dominant spectral peaks at wavelengths ranging from 113-335 millicycles/kb in the 12 donors, with consistent frequency domain spectral patterns, supporting similar use of V segments across healthy individuals. PT-CY recipients had power spectra closely corresponding to the respective donors, however the ATG recipients had relatively dispersed spectra, with spectral centroid shifted towards higher frequencies compared to donors and a reciprocal decline in the low frequency indices. Spectral power was concentrated in the <3 kb and 3-12 kb wavelengths in both groups, consistent with the periodicity observed in the relative V gene segment usage across the repertoire. The analyses reported here demonstrate that the healthy SCT donors have a spectral signature occupying short to intermediate wavelegnths in the frequency domain, PT CY recipients recover with donor-like spectra on the average, however ATG recipients tend to shift towards higher frequencies. These findings are consistent with a normal organized distribution of TRB V segment usage in healthy individuals, with PT-CY preserving this organization more consistently than ATG. Spectral (Fourier) analysis of TRB sequencing data provides a repertoire wide summary of T cell clonal distribution.