Sex-dependent APOE4 neutrophil-microglia interactions drive cognitive impairment in Alzheimer's disease.

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD), with increased odds ratios in female carriers. Targeting amyloid plaques shows modest improvement in male non-APOE4 carriers. Leveraging single-cell transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female carriers with AD, we identify a new subset of neutrophils interacting with microglia associated with cognitive impairment. This phenotype is defined by increased interleukin (IL)-17 and IL-1 coexpressed gene modules in blood neutrophils and in microglia of cognitively impaired female APOE ε4 carriers, showing increased infiltration to the AD brain. APOE4 female IL-17+ neutrophils upregulated the immunosuppressive cytokines IL-10 and TGFß and immune checkpoints, including LAG3 and PD-1, associated with accelerated immune aging. Deletion of APOE4 in neutrophils reduced this immunosuppressive phenotype and restored the microglial response to neurodegeneration, limiting plaque pathology in AD mice. Mechanistically, IL-17F upregulated in APOE4 neutrophils interacts with microglial IL-17RA to suppress the induction of the neurodegenerative phenotype, and blocking this axis supported cognitive improvement in AD mice. These findings provide a translational basis to target IL-17F in APOE ε4 female carriers with cognitive impairment.

PbI2 Passivation of Three Dimensional PbS Quantum Dot Superlattices Toward Optoelectronic Metamaterials.

Lead chalcogenide colloidal quantum dots are one of the most promising materials to revolutionize the field of short-wavelength infrared optoelectronics due to their bandgap tunability and strong absorption. By self-assembling these quantum dots into ordered superlattices, mobilities approaching those of the bulk counterparts can be achieved while still retaining their original optical properties. The recent literature focused mostly on PbSe-based superlattices, but PbS quantum dots have several advantages, including higher stability. In this work, we demonstrate highly ordered 3D superlattices of PbS quantum dots with tunable thickness up to 200 nm and high coherent ordering, both in-plane and along the thickness. We show that we can successfully exchange the ligands throughout the film without compromising the ordering. The superlattices as the active material of an ion gel-gated field-effect transistor achieve electron mobilities up to 220 cm2 V-1 s-1. To further improve the device performance, we performed a postdeposition passivation with PbI2, which noticeably reduced the subthreshold swing making it reach the Boltzmann limit. We believe this is an important proof of concept showing that it is possible to overcome the problem of high trap densities in quantum dot superlattices enabling their application in optoelectronic devices.

Clinical Presentation and Outcomes Following Infection With Vibrio spp, Aeromonas spp, Chromobacterium violaceum, and Shewanella spp Water-Associated Organisms in Tropical Australia, 2015-2022.

Background: Water-associated bacterial infections cause a wide spectrum of disease. Although many of these infections are typically due to human host commensal Staphylococcal or Streptococcal spp, water exposure can result in infections with environmental gram negatives such as Vibrio spp, Aeromonas spp, Chromobacterium violaceum, and Shewanella spp (collectively VACS). Methods: We performed a retrospective analysis of the epidemiology, clinical presentation, and outcomes of deep and superficial infections associated with VACS organisms in our health service between 1 January 2015 and 31 December 2023. Results: We identified 317 patient episodes of infection with VACS organisms over this period. Of these, Aeromonas spp (63%) was the most common, followed by Vibrio spp (19%), Shewanella spp (13%), and C violaceum (5%). The majority were isolated from males (74.4%) and involved the lower limb (67.5%). Mild infections were more common than severe presentations, with only 15 (4.7%) admissions to the intensive care unit and 8 (2.5%) deaths. Colonization occurred in 6.9% of patients, in contrast to the perceived severity of some of these bacteria. Copathogens were common and included Staphylococcus aureus (48%) and enteric bacteria (57%). The majority of patients (60%) had no documented water exposure. Initial empiric antimicrobial therapy presumptively covered the susceptibilities of the isolated organisms in 47.3% of patients; however, a lack of VACS-covering empirical therapy was not associated with readmission. Conclusions: The isolation of a VACS organism in our setting was often not associated with documented water exposure, which has implications for empiric antimicrobial therapy. Severe disease and death were uncommon.

Population sequencing for diversity and transmission analyses.

Genomic diversity in a pathogen population is the foundation for evolution and adaptations in virulence, drug resistance, pathogenesis, and immune evasion. Characterizing, analyzing, and understanding population-level diversity is also essential for epidemiological and forensic tracking of sources and revealing detailed pathways of transmission and spread. For bacteria, culturing, isolating, and sequencing the large number of individual colonies required to adequately sample diversity can be prohibitively time-consuming and expensive. While sequencing directly from a mixed population will show variants among reads, they cannot be linked to reveal allele combinations associated with particular traits or phylogenetic inheritance patterns. Here, we describe the theory and method of how population sequencing directly from a mixed sample can be used in conjunction with sequencing a very small number of colonies to describe the phylogenetic diversity of a population without haplotype reconstruction. To demonstrate the utility of population sequencing in capturing phylogenetic diversity, we compared isogenic clones to population sequences of Burkholderia pseudomallei from the sputum of a single patient. We also analyzed population sequences of Staphylococcus aureus derived from different people and different body sites. Sequencing results confirm our ability to capture and characterize phylogenetic diversity in our samples. Our analyses of B. pseudomallei populations led to the surprising discovery that the pathogen population is highly structured in sputum, suggesting that for some pathogens, sputum sampling may preserve structuring in the lungs and thus present a non-invasive alternative to understanding colonization, movement, and pathogen/host interactions. Our analyses of S. aureus samples show how comparing phylogenetic diversity across populations can reveal directionality of transmission between hosts and across body sites, demonstrating the power and utility for characterizing the spread of disease and identification of reservoirs at the finest levels. We anticipate that population sequencing and analysis can be broadly applied to accelerate research in a broad range of fields reliant on a foundational understanding of population diversity.

Computed tomography diagnosis of pulmonary infarction in acute pulmonary embolism.

INTRODUCTION: Pulmonary infarction is a common sequela of pulmonary embolism (PE) but lacks a diagnostic reference standard. CTPA in the setting of acute PE does not reliably differentiate infarction from other consolidations, such as reversible alveolar hemorrhage or atelectasis. We aimed to assess the diagnostic accuracy for recognizing pulmonary infarction on CT in the acute phase of PE, with follow-up CT as reference. MATERIALS AND METHODS: Initial and follow-up CT scans of 33 patients with acute PE were retrospectively assessed. Two radiologists independently evaluated the presence and size of suspected pulmonary infarction on the initial CT. Confirmation of infarction was established by detection of residual densities on follow-up CT. Sensitivity, specificity and interobserver variability were calculated. RESULTS: In total, 60 presumed infarctions were found in 32 patients, of which 34 infarctions in 21 patients could be confirmed at follow-up. On patient-level, observers' sensitivity/specificity were 91 %/9 %, and 73 %/46 %, respectively, with interobserver agreement by Kappa's coefficient of 0.17. Confirmed infarctions were usually larger than false positive lesions (median approximate volume of 6.6 mL [IQR 0.84-21.3] vs. 1.3 mL [IQR 0.57-6.5], p = 0.040), but still small. An occluding thrombus in a supplying vessel was predictive for confirmed infarction (OR 11, 95%CI 2.1-55), but was not discriminative. CONCLUSIONS: Pulmonary infarction is a common finding in acute PE, and generally small. Radiological identification of infarction was challenging, with considerable interobserver variability. Complete obstruction of the supplying (sub)segmental pulmonary artery was found as the strongest predictor for pulmonary infarction but was not demonstrated to be discriminative.

Assessment of pharmacologically induced changes in canine kidney function by multiparametric magnetic resonance imaging and contrast enhanced ultrasound.

Introduction: Dynamic contrast-enhanced (DCE) MRI and arterial spin labeling (ASL) MRI enable non-invasive measurement of renal blood flow (RBF), whereas blood oxygenation level-dependent (BOLD) MRI enables non-invasive measurement of the apparent relaxation rate (R2*), an indicator of oxygenation. This study was conducted to evaluate the potential role of these MRI modalities in assessing RBF and oxygenation in dogs. The correlation between contrast-enhanced ultrasound (CEUS) and the MRI modalities was examined and also the ability of the MRI modalities to detect pharmacologically induced changes. Methods: RBF, using CEUS, ASL- and DCE-MRI, as well as renal oxygenation, using BOLD-MRI of eight adult beagles were assessed at two time-points, 2­3 weeks apart. During each time point, the anesthetized dogs received either a control (0.9% sodium chloride) or a dopamine treatment. For each time point, measurements were carried out over 2 days. An MRI scan at 3 T was performed on day one, followed by CEUS on day two. Results: Using the model-free model with caudal placement of the arterial input function (AIF) region of interest (ROI) in the aorta, the DCE results showed a significant correlation with ASL measured RBF and detected significant changes in blood flow during dopamine infusion. Additionally, R2* negatively correlated with ASL measured RBF at the cortex and medulla, as well as with medullary wash-in rate (WiR) and peak intensity (PI). ASL measured RBF, in its turn, showed a positive correlation with cortical WiR, PI, area under the curve (AUC) and fall time (FT), and with medullary WiR and PI, but a negative correlation with medullary rise time (RT). During dopamine infusion, BOLD-MRI observed a significant decrease in R2* at the medulla and entire kidney, while ASL-MRI demonstrated a significant increase in RBF at the cortex, medulla and the entire kidney. Conclusion: ASL- and BOLD-MRI can measure pharmacologically induced changes in renal blood flow and renal oxygenation in dogs and might allow detection of changes that cannot be observed with CEUS. However, further research is needed to confirm the potential of ASL- and BOLD-MRI in dogs and to clarify which analysis method is most suitable for DCE-MRI in dogs.

DWARF27 and CAROTENOID CLEAVAGE DIOXYGENASE 7 genes regulate release, germination and growth of gemma in Marchantia polymorpha.

Strigolactones (SLs), a class of carotenoid-derived hormones, play a crucial role in flowering plants by regulating underground communication with symbiotic arbuscular mycorrhizal fungi (AM) and controlling shoot and root architecture. While the functions of core SL genes have been characterized in many plants, their roles in non-tracheophyte plants like liverworts require further investigation. In this study, we employed the model liverwort species Marchantia polymorpha, which lacks detectable SL production and orthologs of key SL biosynthetic genes, including CAROTENOID CLEAVAGE DIOXYGENASE 8 (CCD8) and MORE AXILLARY GROWTH 1 (MAX1). However, it retains some SL pathway components, including DWARF27 (D27) and CCD7. To help elucidate the function of these remaining components in M. polymorpha, knockout mutants were generated for MpD27-1, MpD27-2 and MpCCD7. Phenotypic comparisons of these mutants with the wild-type control revealed a novel role for these genes in regulating the release of gemmae from the gemma cup and the germination and growth of gemmae in the dark. Mpd27-1, Mpd27-2, and Mpccd7 mutants showed lower transcript abundance of genes involved in photosynthesis, such as EARLY LIGHT INDUCED (ELI), and stress responses such as LATE EMBRYOGENESIS ABUNDANT (LEA) but exhibited higher transcript levels of ETHYLENE RESPONSE FACTORS (ERFs) and SL and carotenoid related genes, such as TERPENE SYNTHASE (TS), CCD7 and LECITHIN-RETINAL ACYL TRANSFERASE (LRAT). Furthermore, the mutants of M. polymorpha in the SL pathway exhibited increased contents of carotenoid. This unveils a previously unrecognized role for MpD27-1, MpD27-2 and MpCCD7 in controlling release, germination, and growth of gemmae in response to varying light conditions. These discoveries enhance our comprehension of the regulatory functions of SL biosynthesis genes in non-flowering plants.

Culturing Conditions Dictate the Composition and Pathways Enrichment of Human and Rat Perirenal Adipose-Derived Stromal Cells' Secretomes.

Understanding the impact of various culturing strategies on the secretome composition of adipose-derived stromal cells (ASC) enhances their therapeutic potential. This study investigated changes in the secretome of perirenal ASC (prASC) under different conditions: normoxia, cytokine exposure, high glucose, hypoxia, and hypoxia with high glucose. Using mass spectrometry and enrichment clustering analysis, we found that normoxia enriched pathways related to extracellular matrix (ECM) organization, platelet degranulation, and insulin-like growth factor (IGF) transport and uptake. Cytokine exposure influenced metabolism, vascular development, and protein processing pathways. High glucose affected the immune system, metabolic processes, and IGF transport and uptake. Hypoxia impacted immune and metabolic processes and protein processing. Combined hypoxia and high glucose influenced the immune system, IGF transport and uptake, and ECM organization. Our findings highlight the potential of manipulating culturing conditions to produce secretomes with distinct protein and functional profiles, tailoring therapeutic strategies accordingly.

External validation of the lung-molGPA to predict survival in patients treated with stereotactic radiotherapy for brain metastases of non-small cell lung cancer.

BACKGROUND: In the era of personalized medicine, individualized prognostic models with tumor characteristics are needed to inform patients about survival. Before clinical use, external validation of such models by an independent group is needed. An updated version of the graded prognostic assessment (GPA) estimates survival in patients with brain metastases (BMs) of non-small cell lung cancer (NSCLC). This is the first external validation of the updated Lung-molGPA in patients treated with stereotactic radiotherapy (SRT) for one or more BMs. MATERIALS AND METHODS: Patients treated with SRT for BMs from NSCLC adenocarcinoma were retrospectively included. GPA score was calculated for each patient based on six prognostic factors including age, Karnofsky Performance Status, number of BMs, extracranial metastases, EGFR/ALK status, and PD-L1 expression. Kaplan-Meier analysis evaluated survival probability. Impact of individual prognostic factors on survival was assessed by univariate and multivariate analyses using the Cox proportional hazard model. Predictive performance was evaluated using discrimination (C-statistic) and calibration (Brier test). RESULTS: The cohort (n = 241) was divided into four prognostic groups. Overall median survival was 15 months. Predicted and observed median survival were similar between the original and validation cohorts, apart from the most favorable prognostic group. With adequate C-statistics and Brier scores, the Lung-molGPA provided accurate survival predictions. CONCLUSION: The Lung-molGPA accurately predicted survival in our European population, except for an overestimation of survival in the small most favorable prognostic group. This prognostic model was externally validated and is therefore useful for counseling of patients with BMs of NSCLC adenocarcinoma.

Auxiliary osseous findings in fetlocks of non-racing sports horses with sagittal groove disease of the proximal phalanx on low-field magnetic resonance imaging.

BACKGROUND: Sagittal groove disease of the proximal phalanx in equine athletes is commonly considered a bone stress injury. Repetitive hyperextension of the fetlock under high load is thought to contribute to its development. Concurrent changes are often reported in the dorsal sagittal ridge of the third metacarpus/metatarsus (MC3/MT3). OBJECTIVES: To describe the spectrum of associated osseous abnormalities that are present in the fetlock in a large group of horses diagnosed with sagittal groove disease on low-field magnetic resonance imaging (MRI). STUDY DESIGN: Retrospective, cross-sectional. METHODS: MRI images of horses diagnosed with sagittal groove disease at Equitom Equine Clinic between March 2014 and March 2023 were evaluated using semi-quantitative grading schemes and a sagittal groove disease MRI classification system. RESULTS: MRIs of 132 limbs were evaluated, predominantly from warmbloods used for showjumping (n = 83) and dressage (n = 18). Osseous densification and bone oedema-like signal grades were higher in the dorsal sagittal ridge than palmarly/plantarly (p < 0.001 and p < 0.05, respectively). Grades of both osseous densification and bone oedema-like signal in the dorsal sagittal ridge did not significantly differ between the different sagittal groove disease MRI classifications (both p > 0.05). MAIN LIMITATIONS: Inclusion based on original MRI reports, absence of control group, small numbers within some grading groups hindering statistical analyses. CONCLUSIONS: Findings support the aetiological theories of chronic bone-stress due to loaded fetlock hyperextension however the severity of osseous changes of the dorsal sagittal ridge does not appear to be associated with the severity of sagittal groove disease classification.

HISTORIAL: La enfermedad del surco sagital (SGD) de la falange proximal en equinos atletas, es considerada comúnmente como un lesión de hueso por estrés. Se piensa que la hiperextensión repetitiva del nudo bajo alta carga contribuye a su desarrollo. Cambios concurrentes ocurren menudo en la cresta sagital dorsal del tercer metacarpo/metatarso (MC3/MT3). OBJETIVOS: Describir el espectro de anomalías óseas asociadas que están presentes en el nudo en un gran grupo de caballos diagnosticados con SGD por imágenes de resonancia magnética de baja frecuencia (MRI). DISEÑO DEL ESTUDIO: Retrospectivo, transversal. MÉTODOS: Imágenes de MRI de caballos diagnosticados con SGD en la Clínica Equina Equitom de Marzo 2014 a Marzo 2023, fueron evaluadas usando esquemas de graduación semi­cuantitativos y un sistema de clasificación de SGD MRI. RESULTADOS: MRIs de 132 extremidades fueron evaluadas, proveniente principalmente de caballos de sangre caliente (Warmblood) usados para salto (n = 83) y adiestramiento (n = 18). Densificación ósea y los grados de las señales parecidas al edema de hueso, eran mayores en la cresta sagital dorsal que en palmar/plantar (p < 0.001 y p < 0.05, respectivamente). Los grados de tanto la densificación ósea como de la señal parecida al edema óseo en la cresta sagital, no difirieron significativamente entre las clasificaciones SGD MRI (ambos p > 0.05). LIMITACIONES PRINCIPALES: Inclusión basada en los informes de MRI originales, ausencia de grupo de control, numero pequeño dentro de algunos de los grupos por graduación lo que no permitió hacer análisis estadísticos. CONCLUSIONES: Los hallazgos apoyan las teorías etiológicas del estrés óseo crónico debido a la hiperextensión del nudo bajo carga, sin embargo la severidad de los cambios óseos de la cresta sagital dorsal no parecen estar asociada con la severidad de la clasificación SGD.

The effect of different sweeteners on the oral microbiome: a randomized clinical exploratory pilot study.

Introduction: The aim of the study was to evaluate the modulating effects of five commonly used sweetener (glucose, inulin, isomaltulose, tagatose, trehalose) containing mouth rinses on the oral microbiome. Methods: A single-centre, double-blind, parallel randomized clinical trial was performed with healthy, 18-55-year-old volunteers (N = 65), who rinsed thrice-daily for two weeks with a 10% solution of one of the allocated sweeteners. Microbiota composition of supragingival dental plaque and the tongue dorsum coating was analysed by 16S RNA gene amplicon sequencing of the V4 hypervariable region (Illumina MiSeq). As secondary outcomes, dental plaque red fluorescence and salivary pH were measured. Results: Dental plaque microbiota changed significantly for two groups: inulin (F = 2.0239, p = 0.0006 PERMANOVA, Aitchison distance) and isomaltulose (F = 0.67, p = 0.0305). For the tongue microbiota, significant changes were observed for isomaltulose (F = 0.8382, p = 0.0452) and trehalose (F = 1.0119, p = 0.0098). In plaque, 13 species changed significantly for the inulin group, while for tongue coating, three species changed for the trehalose group (ALDEx2, p < 0.1). No significant changes were observed for the secondary outcomes. Conclusion: The effects on the oral microbiota were sweetener dependant with the most pronounced effect on plaque microbiota. Inulin exhibited the strongest microbial modulating potential of the sweeteners tested. Further full-scale clinical studies are required.

Metabolic blood profile and response to treatment with the pyruvate kinase activator mitapivat in patients with sickle cell disease.

Mitapivat is an investigational, oral, small-molecule allosteric activator of pyruvate kinase (PK). PK is a regulatory glycolytic enzyme that is key in providing the red blood cell (RBC) with sufficient amounts of adenosine triphosphate (ATP). In sickle cell disease (SCD), decreased 2,3-DPG levels increase the oxygen affinity of hemoglobin, thereby preventing deoxygenation and polymerization of sickle hemoglobin. The PK activator mitapivat has been shown to decrease levels of 2,3-DPG and increase levels of ATP in RBCs in patients with SCD. In this phase 2, investigator-initiated, open-label study (https://www.clinicaltrialsregister.eu/ NL8517; EudraCT 2019-003438-18), untargeted metabolomics was used to explore the overall metabolic effects of 8-week treatment with mitapivat in the dose-finding period. In total, 1773 unique metabolites were identified in dried blood spots of whole blood from ten patients with SCD and 42 healthy controls (HCs). The metabolic phenotype of patients with SCD revealed alterations in 139/1773 (7.8%) metabolites at baseline when compared to HCs (false discovery rate-adjusted p < 0.05), including increases of (derivatives of) polyamines, purines, and acyl carnitines. Eight-week treatment with mitapivat in nine patients with SCD altered 85/1773 (4.8%) of the total metabolites and 18/139 (12.9%) of the previously identified altered metabolites in SCD (unadjusted p < 0.05). Effects were observed on a broad spectrum of metabolites and were not limited to glycolytic intermediates. Our results show the relevance of metabolic profiling in SCD, not only to unravel potential pathophysiological pathways and biomarkers in multisystem diseases but also to determine the effect of treatment.

Bleeding assessment following central venous catheter placement, a direct comparison of prospective and retrospective analyses.

BACKGROUND: Reported bleeding incidences following central venous catheter (CVC) placement highly depend on methods of bleeding assessment. To determine the direction and magnitude of the bias associated with retrospective data collection, we used data from the PACER randomized controlled trial and a previous retrospective cohort study. STUDY DESIGN AND METHODS: A patient-level comparison of CVC-related bleeding severity was made among (1) the prospectively collected clinical bleeding assessment of the PACER trial, (2) centralized assessment of CVC insertion site photographs, and (3) retrospective chart review. Interrater reliability for photographic bleeding assessment and retrospective chart review was assessed using Cohen's κ. The magnitude of underreporting of both methods compared to prospective clinical bleeding assessment at different cutoff points of clinically relevant bleeding was assessed using McNemar's test. RESULTS: Interrater reliability was acceptable for both methods (κ = 0.583 and κ = 0.481 for photographic assessment and retrospective chart review, respectively). Photographic bleeding assessment led to significant underreporting of bleeding complications at all cutoff points. Retrospective chart review led to significant underreporting of minor bleeding complications, with an odds ratio (95% CI) of 0.17 (0.044-0.51) for the cutoff point grade 1 (i.e., self-limiting or requiring at most 20 min of manual compression) or higher. There was no significant underreporting of major bleeding complications with retrospective chart review. DISCUSSION: Centralized photographic bleeding assessment and retrospective chart review lead to biased bleeding assessment compared to prospective clinical bleeding assessment.

Diagnostic Value of Microbial Cell-free DNA Sequencing for Suspected Invasive Fungal Infections: A Retrospective Multicenter Cohort Study.

Background: An early diagnosis and treatment of invasive fungal disease (IFD) is associated with improved outcome, but the moderate sensitivity of noninvasive diagnostic tests makes this challenging. Invasive diagnostic procedures such as bronchoalveolar lavage (BAL) have a higher yield but are not without risk. The detection and sequencing of microbial cell-free DNA (mcfDNA) may facilitate a noninvasive diagnosis. Materials: In a prospective observational study, we collected plasma in the 120 hours preceding or following a BAL in patients with hematological malignancies suspected for a pulmonary IFD. The EORTC/MSGERC2020 criteria were used for IFD classification. Sequencing was performed by Karius (Redwood City, CA) using their Karius Test (KT) on plasma and a "research use only test" on BAL fluid if available. Cases with a probable/proven IFD were identified based on standard diagnostic tests on serum and BAL (microscopy, polymerase chain reaction, galactomannan, culture) and used to calculate the sensitivity, specificity, and additional diagnostic value of the KT. Results: Of 106 patients enrolled, 39 (37%) had a proven/probable invasive aspergillosis, 7 (7%) a non-Aspergillus IFD, and 4 (4%) a mixed IFD. The KT detected fungal mcfDNA in 29 (28%) patients. Compared with usual diagnostic tests, the sensitivity and specificity were 44.0% (95% confidence interval [CI], 31.2-57.7) and 96.6% (95% CI, 88.5%-99.1%). Sensitivity of the KT was higher in non-Aspergillus IFD (Mucorales:2/3, Pneumocystis jirovecii: 3/5). On BAL, the sensitivity was 72.2% (95% CI, 62.1-96.3), and specificity 83.3% (95% CI, 49.1-87.5). Conclusions: Sequencing of mcfDNA may facilitate a noninvasive diagnosis of IFD in particular non-Aspergillus IFD. However, on plasma and similar to currently available diagnostics, it cannot be used as a "rule-out" test.

Model-Informed Precision Dosing Using Machine Learning for Levothyroxine in General Practice: Development, Validation and Clinical Simulation Trial.

Levothyroxine is one of the most prescribed drugs in the western world. Dosing is challenging due to high-interindividual differences in effective dosage and the narrow therapeutic window. Model-informed precision dosing (MIPD) using machine learning could assist general practitioners (GPs), but no such models exist for primary care. Furthermore, introduction of decision-support algorithms in healthcare is limited due to the substantial gap between developers and clinicians' perspectives. We report the development, validation, and a clinical simulation trial of the first MIPD application for primary care. Stable maintenance dosage of levothyroxine was the model target. The multiclass model generates predictions for individual patients, for different dosing classes. Random forest was trained and tested on a national primary care database (n = 19,004) with a final weighted AUC across dosing options of 0.71, even in subclinical hypothyroidism. TSH, fT4, weight, and age were most predictive. To assess the safety, feasibility, and clinical impact of MIPD for levothyroxine, we performed clinical simulation studies in GPs and compared MIPD to traditional prescription. Fifty-one GPs selected starting dosages for 20 primary hypothyroidism cases without and then with MIPD 2 weeks later. Overdosage and underdosage were defined as higher and lower than 12.5 µg relative to stable maintenance dosage. MIPD decreased overdosage in number (30.5 to 23.9%, P < 0.01) and magnitude (median 50 to 37.5 µg, P < 0.01) and increased optimal starting dosages (18.3 to 30.2%, P < 0.01). GPs considered lab results more often with MIPD and most would use the model frequently. This study demonstrates the clinical relevance, safety, and effectiveness of MIPD for levothyroxine in primary care.

Validation of a prediction model for early reconnection after cryoballoon ablation.

BACKGROUND: We previously developed an early reconnection/dormant conduction (ERC) prediction model for cryoballoon ablation to avoid a 30-min waiting period with adenosine infusion. We now aimed to validate this model based on time to isolation, number of unsuccessful cryo-applications, and nadir balloon temperature. METHODS: Consecutive atrial fibrillation patients who underwent their first cryoballoon ablation in 2018-2019 at the Leiden University Medical Center were included. Model performance at the previous and at a new optimal cutoff value was determined. RESULTS: A total of 201 patients were included (85.57% paroxysmal AF, 139 male, median age 61 years (IQR 53-69)). ERC was found in 35 of 201 included patients (17.41%) and in 41 of 774 veins (5.30%). In the present study population, the previous cutoff value of - 6.7 provided a sensitivity of 37.84% (previously 70%) and a specificity of 89.07% (previously 86%). Shifting the cutoff value to - 7.2 in both study populations resulted in a sensitivity of 72.50% and 72.97% and a specificity of 78.22% and 78.63% in data from the previous and present study respectively. Negative predictive values were 96.55% and 98.11%. Applying the model on the 101 patients of the present study with all necessary data for all veins resulted in 43 out of 101 patients (43%) not requiring a 30-min waiting period with adenosine testing. Two patients (2%) with ERC would have been missed when applying the model. CONCLUSIONS: The previously established ERC prediction model performs well, recommending its use for centers routinely using adenosine testing following PVI.

Azathioprine/hydroxyurea preconditioning prior to nonmyeloablative matched sibling donor hematopoietic stem cell transplantation in adults with sickle cell disease: A prospective observational cohort study.

Nonmyeloablative, matched sibling donor hematopoietic stem cell transplantation with alemtuzumab/total body irradiation (TBI) conditioning is a curative therapy with low toxicity for adults with sickle cell disease (SCD). However, relatively low donor chimerism levels and graft rejection remain important challenges. We hypothesized that adding azathioprine/hydroxyurea preconditioning will improve donor chimerism levels and reduce graft failure rate. In this prospective cohort study, we enrolled consecutive adult patients with SCD undergoing matched sibling donor transplantation at the Amsterdam UMC. Patients received azathioprine 150 mg/day and hydroxyurea 25 mg/kg/day for 3 months prior to alemtuzumab 1 mg/kg and 300 cGy TBI conditioning. Twenty patients with SCD (median age 26 years [range 19-49], 13 females) were transplanted. Median follow-up was 46.0 months (IQR 21.8-57.9). One-year overall survival and event-free survival (graft failure or death) were both 95% (95% confidence interval 86-100). Mean donor myeloid and T-cell chimerism 1-year post-transplant were 95.2% (SD ±10.6) and 67.3% (±15.3), respectively. One patient (5%) experienced graft failure without autologous regeneration, resulting in infections and death. All other patients had a corrected SCD phenotype and were able to discontinue sirolimus. Three patients were successfully treated with alemtuzumab (1 mg/kg) after the transplant because of declining donor chimerism and cytopenias to revert impending graft rejection. Toxicity was mostly related to sirolimus and alemtuzumab. One patient developed steroid-responsive grade II intestinal acute graft-versus-host disease. Collectively, preconditioning with azathioprine/hydroxyurea prior to nonmyeloablative matched sibling donor transplantation resulted in excellent event-free survival and robust donor T-cell chimerism, enabling the successful withdrawal of sirolimus. ClinicalTrials.gov: NCT05249452.

Immunogenicity of a bivalent BA.1 COVID-19 booster vaccine in people with HIV in the Netherlands.

OBJECTIVE: We evaluated the immunogenicity of a bivalent BA.1 COVID-19 booster vaccine in people with HIV (PWH). DESIGN: Prospective observational cohort study. METHODS: PWH aged ≥45 years received Wuhan-BA.1 mRNA-1273.214 and those <45 years Wuhan-BA.1 BNT162b2. Participants were propensity score-matched 1 : 2 to people without HIV (non-PWH) by age, primary vaccine platform (mRNA-based or vector-based), number of prior COVID-19 boosters and SARS-CoV-2 infections, and spike (S1)-specific antibodies on the day of booster administration. The primary endpoint was the geometric mean ratio (GMR) of ancestral S1-specific antibodies from day 0 to 28 in PWH compared to non-PWH. Secondary endpoints included humoral responses, T-cell responses and cytokine responses up to 180 days post-vaccination. RESULTS: Forty PWH received mRNA-1273.214 ( N  = 35) or BNT162b2 ( N  = 5) following mRNA-based ( N  = 29) or vector-based ( N  = 11) primary vaccination. PWH were predominantly male (87% vs. 26% of non-PWH) and median 57 years [interquartile range (IQR) 53-59]. Their median CD4 + T-cell count was 775 (IQR 511-965) and the plasma HIV-RNA load was <50 copies/ml in 39/40. The GMR of S1-specific antibodies by 28 days post-vaccination was comparable between PWH [4.48, 95% confidence interval (CI) 3.24-6.19] and non-PWH (4.07, 95% CI 3.42-4.83). S1-specific antibody responses were comparable between PWH and non-PWH up to 180 days, and T-cell responses up to 90 days post-vaccination. Interferon-γ, interleukin (IL)-2, and IL-4 cytokine concentrations increased 28 days post-vaccination in PWH. CONCLUSION: A bivalent BA.1 booster vaccine was immunogenic in well treated PWH, eliciting comparable humoral responses to non-PWH. However, T-cell responses waned faster after 90 days in PWH compared to non-PWH.

Melioidosis and Activation from Latency: The "Time Bomb" Has Not Occurred.

Burkholderia pseudomallei, the causative agent of melioidosis has long been considered able to exist in a latent form. Seropositivity among U.S. soldiers returning from the Vietnam conflict led to melioidosis being dubbed "the Vietnamese time bomb." Cases assigned to "(re)activation from latency" over 30 years of the Darwin Prospective Melioidosis Study (DPMS) were reviewed and reassessed and additional cases from DPMS years 31-34 were added. Historical reports of melioidosis attributed to activation from latency were reviewed. Some earlier DPMS cases and most historical cases described as activation from latency more accurately reflect undiagnosed chronic melioidosis, often with relapsing-remitting courses, rather than truly latent, asymptomatic infection. Such protracted disease should now be diagnosable much earlier, provided melioidosis is considered and laboratory facilities are available. The longest plausible duration of asymptomatic latency remains 29 years. In conclusion, activation from latency is a rare event in melioidosis, accounting in our analysis for under 3% of DPMS cases, consistent with why the Vietnamese time bomb never eventuated.