Leiden University Medical Centre
Recent publications
The increase in age-related comorbidities, such as cardiometabolic diseases, has become a global health priority. There is a growing need to find new parameters capable of improving the detection of cardiometabolic risk factors, and circulating endocannabinoids (eCBs) are a promising tool in this context. Here, we aimed to investigate the relationship between plasma levels of eCBs and their analogues with body composition and cardiometabolic risk factors in middle-aged adults. Seventy-two individuals (54% women; 53.6 ± 5.1 years old) were included in this study. Plasma levels of eCBs and analogues were determined using liquid chromatography-tandem mass spectrometry. Body composition was measured by dual-energy X-ray absorptiometry. Cardiometabolic risk factors (i.e., glucose and lipid profile, blood pressure, liver and renal parameters, and gonadal hormones) were also assessed. The plasma levels of 1- and 2-arachidonylglycerol (1-AG&2-AG) were positively correlated with adiposity (all r ≥ 0.23, P < 0.05). Interestingly, the plasma levels of 1-AG&2-AG, arachidonoylethanolamide, and palmitoyl-ethanolamide were positively correlated with the homeostatic model assessment index – Insulin Resistance (HOMA-IR) (all r ≥ 0.32, P < 0.01). Our results also showed that high levels of 1-AG&2-AG, arachidonoylethanolamide, linoleoyl ethanolamide, and palmitoleoyl ethanolamide were correlated with poorer liver (all r ≥ 0.27, P < 0.05), kidney (all r ≥ 0.24, P < 0.05), and gonadal function parameters (testosterone: all r > 0.26, P < 0.05, SHBG: 1-AG&2-AG r=-0.33, P < 0.01). The plasma levels of some eCBs and analogues are correlated with a worse cardiometabolic profile in middle-aged adults.
Objective Adopting healthy behavior is vital for preventing chronic diseases. Mobile health (mHealth) interventions utilizing virtual coaches (i.e., artificial intelligence conversational agents) can offer scalable and cost-effective solutions. Additionally, targeting multiple unhealthy behaviors, like low physical activity and smoking, simultaneously seems beneficial. We developed Perfect Fit, an mHealth intervention with a virtual coach providing personalized feedback to simultaneously promote smoking cessation and physical activity. Through innovative methods (e.g., sensor technology) and iterative development involving end-users, we strive to overcome challenges encountered by mHealth interventions, such as shortage of evidence-based interventions and insufficient personalization. This paper outlines the content of Perfect Fit and the protocol for evaluating its feasibility, acceptability, and preliminary effectiveness, the role of participant characteristics, and the study's feasibility. Methods A single-arm, mixed-method, real-world evaluation study will be conducted in the Netherlands. We aim to recruit 100 adult daily smokers intending to quit within 6 weeks. The personalized intervention will last approximately 16 weeks. Primary outcomes include Perfect Fit's feasibility and acceptability. Secondary outcomes are preliminary effectiveness and study feasibility, and we will measure participant characteristics. Quantitative data will be collected through questionnaires administered at baseline, post-intervention and 2, 6, and 12 months post-intervention. Qualitative data will be gathered via semi-structured interviews post-intervention. Data analysis will involve descriptive analyses, generalized linear mixed models (quantitative) and the Framework Approach (qualitative), integrating quantitative and qualitative data during interpretation. Conclusions This study will provide novel insight into the potential of interventions like Perfect Fit, as a multiple health behavior change strategy. Findings will inform further intervention development and help identify methods to foster feasibility and acceptability. Successful mHealth interventions with virtual coaches will prevent chronic diseases and promote public health.
Objectives Videofluoroscopic swallowing studies (VFSS) remain the gold standard for the instrumental assessment of oropharyngeal swallowing disorders alongside flexible endoscopic evaluation of swallowing (FEES), requiring a high standard of quality and correct implementation. The current best practice position statements aim to guide the clinical practice of VFSS in individuals experiencing swallowing disorders. Materials and methods An international expert consensus panel with expertise in oropharyngeal dysphagia, comprised of radiologists, speech-language therapists, otolaryngologists, and other professionals in the field, convened by the European Society of Swallowing Disorders (ESSD) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), developed best practice position statements. They were established using an online Delphi methodology involving an online panel discussion and item preparation and three consecutive rounds. Consensus was reached when ≥ 80% of the participants agreed on a specific recommendation. Results Eighteen best practice position statements were formulated, thereby establishing standard recommendations on the technical performance of VFSS. They cover VFSS planning, correct implementation, documentation, radiation protection, equipment and maintenance, and education and training. Conclusion These position statements summarise the panel’s deliberations and recommendations in performing VFSS, representing the agreed consensus of experts from ESSD and ESGAR. They provide a structured framework for optimising and standardising the performance of VFSS in patients with swallowing disorders. Key Points Question Significant regional and national differences in clinical practice when performing VFSS highlight the need for interdisciplinary recommendations to optimise patient care . Findings Eighteen statements were developed by representatives of the ESSD and the ESGAR . Clinical relevance These best practice position statements on the technical performance of VFSS may serve as a basis for standardising the procedure and ensuring high-quality service .
Background and Objectives Foetal and neonatal alloimmune thrombocytopenia (FNAIT) results from maternal platelet‐directed antibodies and can result in severe intracranial haemorrhage (ICH) in foetuses and newborns. Screening for human platelet antigen‐1a (HPA‐1a)‐directed antibodies during pregnancy could allow timely intervention with antenatal treatment and prevent ICH. We assessed the cost effectiveness of HPA‐1a typing and anti‐HPA‐1a‐screening as part of the prenatal screening programme. Materials and Methods Different HPA‐1a screening scenarios were tested in a decision analysis model and assessed for diagnostic, treatment, intervention and lifetime costs and prevention effects compared to the current situation without screening in the Netherlands. Model parameters were based on available data, literature and expert opinions. One‐way sensitivity analysis and probabilistic sensitivity analysis were performed. Results Adding screening for anti‐HPA‐1a antibodies to the current antenatal screening programme of the Netherlands will lead to an additional cost of €4.7 million per year and a gain of 226 quality‐adjusted life years (QALYs) per year, indicating an incremental cost–effectiveness ratio (ICER) of €20,782 per QALY gained. One‐way sensitivity analysis showed that the uncertainty around the incidence of ICH, lifetime costs of disabled children and the probability of having antibody quantitation >3.0 IU/mL at 20 weeks had the highest effect on the ICER. Conclusion Antenatal anti‐HPA‐1a screening might be cost effective. To obtain more knowledge and thereby to improve risk stratification, a pilot screening programme is warranted.
Solid cancers are the most prevalent malignancies with rising trend and mortality worldwide. Behavioural risk factors for these cancers are not completely clear, and the effect of genetic factors for their development remains unknown. This study investigates the genetic relationship between 3 solid cancer types with other human traits. We used linkage disequilibrium score regression (LDSC) to analyze the links between lung carcinoma, esophageal carcinoma and colon cancer, and several phenotypes that include smoking, habits and body measurements. We then applied a latent causal variable (LCV) approach to elucidate their causal effects. Finally, we performed a gene selection for each cancer type using genome wide association studies and gene expression profiles. LDSC revealed a significant association of the 3 cancer types with body mass index, while causative effect analysis identified that the trait “Exposure to tobacco smoke at home” showed a causal effect on lung squamous cancer. Further analysis identified shared gene loci using gene expression profiles and GWAS including BRCA2, HLA-DQB1, SLC44A4, and ZNF623 in lung squamous cell carcinoma, COCH, CHRM3, SYNPO2, and TAF4B in esophageal adenocarcinoma, and BMP4, and SYN3 in colorectal cancer. This study suggests novel insights into the genetic links between lung carcinoma, esophageal carcinoma and colon cancer. Utilising computational approaches for genetic correlation, causal assessment, and gene selection, we identified shared genetic susceptibilities and specific genetic mechanisms. These findings revealed new targets to further elucidate the genetic basis of these 3 solid cancers, and for the development of preventive and therapeutic approaches.
Background Mifepristone is a selective progesterone receptor modulator with decades of data demonstrating its potential as a highly effective emergency as well as non-emergency contraceptive. Despite considerable evidence pointing to the potential effectiveness of mifepristone as a non-emergency contraceptive, no systematic review has been conducted to synthesise the available evidence. This systematic review aims to synthesise the current evidence on the use of mifepristone as a non-emergency contraceptive to prevent pregnancy among cisgender girls and women of reproductive age. Methods We developed an electronic search strategy in collaboration with the research librarian. We will search five databases (Ovid Medline, CINAHL, EMBASE, Cochrane-Central Trials and Global Health) from inception and identify additional studies using several grey literature search strategies. All databases will be searched from inception, and we planned to complete the search by 30 June 2024. An Ovid Medline search strategy conducted on 24 May 2024 is provided as an example. We will include all studies that involve cisgender girls and/or women of reproductive age (defined as 54 years or younger), which assessed mifepristone as a non-emergency contraceptive to prevent pregnancy. The primary outcome is contraceptive effectiveness. Two independent reviewers will screen studies for eligibility through title, abstract, and full-text review. We will extract data with Covidence software using a Cochrane Effective Practice and Organisation of Care (EPOC)-adapted data-extraction tool and will assess risk of bias using the EPOC risk of bias tool and the Newcastle–Ottawa Scale. If sufficient data are available, we will conduct a meta-analysis using fixed and/or random effect models. However, if we are unable to conduct a meta-analysis, we will present the results narratively using the synthesis without meta-analysis guidelines and the EPOC table recommended for presenting findings without meta-analysis. Grades of Recommendation, Assessment, Development and Evaluation will be used to assess the quality of the evidence. We will report this review according to Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. Ethics and dissemination This review is focused on secondary data and does not require any ethical approval. We aim to publish the review in a peer-reviewed scientific journal to promote knowledge transfer and present results using other knowledge translation mediums. PROSPERO registration number CRD42024554720.
Background The Bacillus Calmette-Guérin (BCG) vaccine, currently the sole authorized vaccine against tuberculosis (TB), demonstrates limited effectiveness in safeguarding adolescents and adults from active TB, even when administered as a booster with either BCG itself or heterologous vaccine candidates. To effectively control the persistent epidemic of adult TB, it is imperative to investigate the mechanisms responsible for the suboptimal efficacy of the BCG prime-boosting strategy against primary Mycobacterium tuberculosis (M.tb) infection. Methods C57BL/6J mice were immunized with the BCG vaccine either once or twice, followed by analysis of lung tissue to assess changes in cytokine levels. Additionally, varying intervals between vaccinations and detection times were examined to study IL-10 expression across different organs. IL-10-expressing cells in the lungs, spleen, and lymph nodes were analyzed through FACS and intracellular cytokine staining (ICS). BCG-revaccinated IL-10−/− mutant mice were compared with wild-type mice to evaluate antigen-specific IgG antibody and T cell responses. Protection against M.tb aerosol challenge was evaluated in BCG-revaccinated mice, either untreated or treated with anti-IL-10R monoclonal antibody. Results IL-10 was significantly upregulated in the lungs of BCG-revaccinated mice shortly after the booster immunization. IL-10 expression peaked in the lungs 3–6 weeks post-revaccination and was also detected in lymph nodes and spleen as early as 2 weeks following the booster dose, regardless of the intervals between the prime and booster vaccinations. The primary sources of IL-10 in these tissues were identified as macrophages and dendritic cells. Blocking IL-10 signaling in BCG-revaccinated mice—either by using IL-10−/− mutant mice or administering anti-IL-10R monoclonal antibody increased levels of antigen-specific IFN-γ⁺ or IL-2⁺ CD4⁺ T cells, enhanced central and effector memory CD4⁺ T cell responses, and provided better protection against aerosol infection with 300 CFUs of M.tb. Conclusion Our findings are crucial for formulating effective immunization strategies related to the BCG vaccine and for developing efficacious adult TB vaccines. Graphical abstract
Background This study aims to analyse the effects of reducing Received Dose Intensity (RDI) in chemotherapy treatment for osteosarcoma patients on their survival by using a novel approach. Previous research has highlighted discrepancies between planned and actual RDI, even among patients randomized to the same treatment regimen. To mitigate toxic side effects, treatment adjustments, such as dose reduction or delayed courses, are necessary. Toxicities are therefore risk factors for mortality and predictors of future exposure levels. Toxicity introduces post-assignment confounding when assessing the causal effect of chemotherapy RDI on survival outcomes, a topic of ongoing debate. Methods Chemotherapy administration data from BO03 and BO06 Randomized Clinical Trials (RCTs) in ostosarcoma are employed to emulate a target trial with three RDI-based exposure strategies: 1) standard, 2) reduced, and 3) highly-reduced RDI. Investigations are conducted between subgroups of patients characterised by poor or good Histological Responses (HRe), i.e., the strongest known prognostic factor for survival in osteosarcoma. Inverse Probability of Treatment Weighting (IPTW) is first used to transform the original population into a pseudo-population which mimics the target randomized cohort. Then, a Marginal Structural Cox Model with effect modification is employed. Conditional Average Treatment Effects (CATEs) are ultimately measured as the difference between the Restricted Mean Survival Time of reduced/highly-reduced RDI strategy and the standard one. Confidence Intervals for CATEs are obtained using a novel IPTW-based bootstrap procedure. Results Significant effect modifications based on HRe were found. Increasing RDI-reductions led to contrasting trends for poor and good responders: the higher the reduction, the better (worsen) was the survival in poor (good) reponders. Due to their intrinsic resistance to chemotherapy, poor reponders could benefit from reduced RDI, with an average gain of 10.2 and 15.4 months at 5-year for reduced and highly-reduced exposures, respectively. Conclusions This study introduces a novel approach to (i) comprehensively address the challenges related to the analysis of chemotherapy data, (ii) mitigate the toxicity-treatment-adjustment bias, and (iii) repurpose existing RCT data for retrospective analyses extending beyond the original trials’ intended scopes.
High-dose methotrexate (HD-MTX)-based polychemotherapy is widely used for patients with central nervous system (CNS) lymphoma. The pharmacokinetic (PK) variability and unpredictable occurrence of toxicity remain major concerns in HD-MTX treatment. This study aimed to characterize the population PK of HD-MTX in patients with CNS lymphoma and to identify baseline predictors and exposure thresholds that predict a high risk of nephro- and hepatotoxicity. Routinely monitored serum MTX concentrations after intravenous infusion of HD-MTX and MTX dosing information were collected retrospectively. Acute event of toxicity (≥ grade 1) was defined according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 on the basis of serum creatinine and alanine aminotransferase. A population PK model was developed in NONMEM. Toxicity data were analyzed using a logistic regression model, and potential baseline and exposure-related predictors were investigated. In total, 1584 MTX concentrations from 110 patients were available for analysis. A two-compartment population PK model adequately described the data. Estimated glomerular filtration rate (eGFR), treatment regimen, albumin, alkaline phosphatase, and body weight were identified as significant covariates that explain the PK variability of HD-MTX. Baseline eGFR and sex were identified as significant predictors for renal toxicity, and MTX dose (mg/m2) was the strongest predictor for hepatotoxicity. The MTX area under the concentration–time curve (AUC24–∞) and concentration at 24 h (C24h) were shown to correlate with renal toxicity only, and 49,800 μg/L × h (109.6 μmol/L × h) and C24h > 3930 μg/L (8.65 μmol/L) were potential exposure thresholds predicting high risk (proportion > 60%). A population PK model was developed for HD-MTX in patients with CNS lymphoma. The toxicity analysis showed that lower baseline eGFR and male sex, and higher MTX dose are associated with increased risk of acute nephro- and hepatotoxicity, respectively. The proposed exposure thresholds that predict high risk of renal toxicity and the developed models hold the potential to guide HD-MTX dosage individualization and better prevent acute toxicity.
Background Detection of infection with Mycobacterium leprae allows timely prophylactic treatment, thereby reducing transmission as well as the risk of permanent, leprosy-associated nerve damage. However, since there is no worldwide-implemented standard test for M. leprae infection, detection of infection in asymptomatic individuals remains a major challenge for control programs in endemic areas. In previous studies, we developed and field-tested a lateral flow assay (LFA) quantitatively detecting human IgM against M. leprae -specific phenolic glycolipid I (anti-PGL-I), a marker for both active and past infection. This rapid test utilizes luminescent, background-free, up-converting reporter particles (UCP) and immunochromatography (i.e. the UCP-LF test platform) for accurate quantitation of anti-PGL-I IgM without operator bias. The aim of this study was to evaluate the final version of this quantitative UCP-based rapid test (i.e. PGL-I QURapid), using serum and fingerstick blood (FSB). Methods The test comprises a lateral flow strip, in a standard plastic or biodegradable cassette. It can be provided with a humanized, recombinant control to monitor test performance and calculate accurate anti-PGL-I IgM levels. The performance of this QUR-test was assessed using serum and FSB from patients with leprosy (n = 214), tuberculosis ( n = 20), buruli ulcer ( n = 19), leishmaniasis ( n = 14), non-tuberculous mycobacterial ( n = 35) infections, as well as healthy Dutch individuals ( n = 710) and humanized, recombinant anti-PGL-I IgM antibodies. Plot receiver operating characteristic curves were created and sensitivity (Sn), specificity (Sp) and the area under the curve were calculated to evaluate test performance. Results Test results classified multibacillary leprosy patients with 95.0% Sn and 100% Sp using serum and 91.5% Sn and 99.8% Sp using FSB. Qualitative test results could be read after 2 min flow time, with accurate quantitation from 10 min onwards. The new anti-PGL-I IgM control supports production of batches with predetermined seropositivity thresholds and monitoring of the PGL-I QUR-test in various settings. Conclusion The operational version of the PGL-I QURapid with point-of-care applicability, meets the WHO target product profile criteria. Thus, this QUR-test is ready for public health implementations. Graphical Abstract
Background Since 2015 multiple combination treatments became available for metastatic hormone-sensitive prostate cancer (mHSPC) without effectiveness cross-comparison. Health-related quality of life (HRQoL) could aid in decision-making. Methods We systematically reviewed HRQoL publications (January 2015–September 2024) of phase III randomized controlled trials (RCTs) in mHSPC using PRISMA guidelines, cross-compared HRQoL results and assessed usefulness to support decision-making (PROSPERO: CRD42023470698). International Society for Quality-of-Life Research (ISOQOL) recommended standards were used to assess quality of Patient-reported Outcomes reporting. Findings We identified nine HRQoL publications from eight RCTs investigating an estradiol patch, or either radiotherapy, docetaxel, androgen-receptor-pathway-inhibitor (ARPI) abiraterone, apalutamide or enzalutamide added to androgen deprivation therapy (ADT) versus ADT ± placebo in ≥8000 patients. Only three studies were considered to have low overall risk of bias (RoB2). Eight HRQoL measures (1–4 per study) were used; 3/5 RCTs investigating an ARPI measured HRQoL using Brief Pain Inventory (BPI-SF), and Functional Assessment of Cancer Therapy-Prostate (FACT-P). Overall, the quality of PRO reporting was high, but PRO-hypothesis was provided by only 25% and reasons for missing data explained in only 50% of RCTs. Interpretation Conceptual and methodological HRQoL heterogeneity, along with risk of biases, hampers cross-comparison and failed to robustly support decision-making underscoring the importance of harmonizing methodological approaches. Funding None.
Across the lifespan, diet and physical activity profiles substantially influence immunometabolic health. DNA methylation, as a tissue‐specific marker sensitive to behavioral change, may mediate these effects through modulation of transcription factor binding and subsequent gene expression. Despite this, few human studies have profiled DNA methylation and gene expression simultaneously in multiple tissues or examined how molecular levels react and interact in response to lifestyle changes. The Growing Old Together (GOTO) study is a 13‐week lifestyle intervention in older adults, which imparted health benefits to participants. Here, we characterize the DNA methylation response to this intervention at over 750 thousand CpGs in muscle, adipose, and blood. Differentially methylated sites are enriched for active chromatin states, located close to relevant transcription factor binding sites, and associated with changing expression of insulin sensitivity genes and health parameters. In addition, measures of biological age are consistently reduced, with decreases in grimAge associated with observed health improvements. Taken together, our results identify responsive molecular markers and demonstrate their potential to measure progression and finetune treatment of age‐related risks and diseases.
Background Insights into quantitative differences between core laboratory and center‐reported echocardiographic assessment of the native and bioprosthetic aortic valve are lacking. We aimed to explore clinically relevant differences between these evaluations. Methods Data were used from the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Pivotal Trial for the Avalus valve. In this trial, patients with an indication for surgical aortic valve replacement (SAVR) due to aortic stenosis or regurgitation (AR) were enrolled. Serial echocardiographic examinations were performed at each center and blindly reanalyzed by an independent echocardiographic core laboratory (ECL). For the bioprosthetic valve analysis, postoperative data throughout the 5‐year follow‐up were pooled. Differences between the ECL and the centers in continuous parameters were quantified in mean differences and intraclass correlation coefficients (ICCs). Agreement on AR, paravalvular leak (PVL), and prosthesis‐patient mismatch (PPM) classification was investigated using Cohen's kappa coefficients. Results The analysis on the native aortic valve was performed on 1118 echocardiograms. The relative mean difference was largest for the left ventricular outflow tract (LVOT) area, followed by stroke volume and effective orifice area (index), with center‐reported values being 11%–7% higher. High ICCs of around 0.90 were observed for the parameters peak aortic jet velocity, mean pressure gradient, and the velocity‐time integral across the aortic valve. Over 5000 echocardiograms were available for the bioprosthetic valve analysis. Therein, comparable results were observed. The kappa coefficient was 0.59 (95% confidence interval [CI] 0.56, 0.63) for agreement on native AR, 0.28 (95% CI 0.18, 0.37) for PVL, and 0.42 (95% CI 0.40, 0.44) for PPM. Conclusions There is high agreement between the ECL and clinical centers on continuous‐wave Doppler‐related measurements. In contrast, agreement is low for parameters that involve measurement of the LVOT diameter. These results provide important context for the interpretation of aortic valve performance in studies that lack central ECL evaluation. Trial Registration ClinicalTrials.gov identifier: NCT02088554
The asialoglycoprotein receptor 1 (ASGR1), a multivalent carbohydrate-binding receptor that primarily is responsible for recognizing and eliminating circulating glycoproteins with exposed galactose (Gal) or N-acetylgalactosamine (GalNAc) as terminal glycan residues, has been implicated in modulating the lipid metabolism and reducing cardiovascular disease burden. In this study, we investigated the impact of ASGR1 deficiency (ASGR1−/−) on atherosclerosis by evaluating its effects on plaque formation, lipid metabolism, circulating immunoinflammatory response, and circulating N-glycome under the hypercholesterolemic condition in ApoE-deficient mice. After 16 weeks of a western-type diet, ApoE−/−/ASGR1−/− mice presented lower plasma cholesterol and triglyceride levels compared to ApoE−/−. This was associated with reduced atherosclerotic plaque area and necrotic core formation. Interestingly, ApoE−/−/ASGR1−/− mice showed increased levels of circulating immune cells, increased AST/ALT ratio, and no changes in the N-glycome profile and liver morphology. The liver of ApoE−/−/ASGR1−/− mice, however, presented alterations in the metabolism of lipids, xenobiotics, and bile secretion, indicating broader alterations in liver homeostasis beyond lipids. These data suggest that improvements in circulating lipid metabolism and atherosclerosis in ASGR1 deficiency is paralleled by a deterioration of liver injury. These findings point to the need for additional evaluation before considering ASGR1 as a pharmacological target for dyslipidemia and cardiovascular disorders. Graphical abstract
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3,691 members
PB De Witte
  • Department of Orthopedic Surgery
Pieter Kitslaar
  • Department of Radiology
Karoly Szuhai
  • Cell and Chemical Biology
Yotam Raz
  • Department of Molecular Epidemiology
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Leiden, Netherlands