Identifying risk factors of anti-TNF induced skin lesions and other adverse events in paediatric patients with inflammatory bowel disease.

Objectives: While higher infliximab (IFX) trough concentrations (TCs) are associated with better outcomes in patients with inflammatory bowel disease (IBD), they could pose a risk for adverse events (AEs), including IFX-induced skin lesions. Therefore, we studied correlations between IFX TCs and occurrence of AEs in paediatric IBD patients.

Methods: In this single-centre study, all children with Crohn's disease (CD) and ulcerative colitis (UC) receiving IFX maintenance therapy who underwent proactive drug monitoring between March 2015 and August 2022 were included.

Combined deficient response to polysaccharide-based and protein-based vaccines predicts a severe clinical phenotype.

Objectives: Antibody response on polysaccharide- and protein-based vaccines is useful to test B cell functionality. As only few studies have explored the value of studying immune response to both vaccines, we evaluated the clinical value of anti-polysaccharide and anti-protein Luminex-based multiplex assays in context of primary immunodeficiency (PID) diagnosis.

Methods: A 10-plex Luminex-based assay detecting antibodies to ten pneumococcal polysaccharide (PnPS) serotypes [present in unconjugated Pneumovax, not in 13-valent pneumococcal conjugated vaccine (PCV)] and a 5-plex assay detecting antibodies to five protein antigens (present in DTap/Tdap) were clinically validated in healthy individuals (n=99) and in retrospective (n=399) and prospective (n=108) patient cohorts.

Evaluation of serum cytokines and acute phase proteins as possible pharmacodynamic biomarkers to monitor endoscopic remission during ustekinumab therapy in patients with Crohn's disease.

Background: Since not all Crohn's disease (CD) patients respond adequately to ustekinumab therapy, biomarkers could aid to monitor treatment response and optimize therapeutic outcomes.

Objectives: To explore the dynamics of serum biomarker concentrations to monitor the response to ustekinumab treatment in CD patients.

Design: Retrospective, exploratory study to evaluate concentrations of serum cytokines and acute phase proteins and their relation to endoscopic remission in CD patients during ustekinumab treatment.

Detection of Breast Cancer-Specific Extracellular Vesicles with Fiber-Optic SPR Biosensor.

Extracellular vesicles (EVs) have attracted great attention as potential biomarkers for cancer diagnostics. Although several technologies have been developed for EV detection, many of them are still not applicable to clinical settings as they rely on complex EV isolation processes, while lacking sensitivity, specificity or standardization. To solve this problem, we have developed a sensitive breast cancer-specific EV detection bioassay directly in blood plasma using a fiber-optic surface plasmon resonance (FO-SPR) biosensor, previously calibrated with recombinant EVs.

A Model-Based Tool for Guiding Infliximab Induction Dosing to Maximize Long-term Deep Remission in Children with Inflammatory Bowel Diseases.

Background And Aims: Adequate infliximab concentrations during induction treatment are predictive for deep remission [corticosteroid-free clinical and endoscopic remission] at 6 months in children with inflammatory bowel diseases [IBD]. Under standard infliximab induction dosing, children often have low infliximab trough concentrations. Model-informed precision dosing [MIPD; i.

Blocking interleukin-17 in psoriasis: Real-world experience from the PsoPlus cohort.

Background: Real-world studies on the use of biologics in psoriasis (Pso) are increasing, but still scarce. Trough concentrations (C s) of interleukin-17 inhibitors (IL-17i) seem promising for clinical decision-making, but their value in daily practice has yet to be proven.

Objectives: To report on IL-17i effectiveness, treatment modifications and C use in our clinic.

Clinically relevant dosing and pharmacokinetics of DNA-encoded antibody therapeutics in a sheep model.

DNA-encoded delivery and expression of antibody therapeutics presents an innovative alternative to conventional protein production and administration, including for cancer treatment. To support clinical translation, we evaluated this approach in 18 40-45 kg sheep, using a clinical-matched intramuscular electroporation (IM EP) and hyaluronidase-plasmid DNA (pDNA) coformulation setup. Two cohorts of eight sheep received either 1 or 4 mg pDNA encoding an ovine anti-cancer embryonic antigen (CEA) monoclonal antibody (mAb; OVAC).

Predictive models assessing the response to ustekinumab highlight the value of therapeutic drug monitoring in Crohn's disease.

Background: Despite the therapeutic efficacy of Ustekinumab (UST) in Crohn's disease (CD), loss of response (LOR) is observed over time. This study aims to evaluate the impact of the UST pharmacokinetics (PK) at induction on clinical and endoscopic outcomes, as well as to find predictive markers of UST response.

Methods: This retrospective study included 80 CD patients.

Multi-model averaging improves the performance of model-guided infliximab dosing in patients with inflammatory bowel diseases.

Infliximab dosage de-escalation without prior knowledge of drug concentrations may put patients at risk for underexposure and trigger the loss of response. A single-model approach for model-informed precision dosing during infliximab maintenance therapy has proven its clinical benefit in patients with inflammatory bowel diseases. We evaluated the predictive performances of two multi-model approaches, a model selection algorithm and a model averaging algorithm, using 18 published population pharmacokinetic models of infliximab for guiding dosage de-escalation.

Real-world Endoscopic and Histological Outcomes Are Correlated with Ustekinumab Exposure in Patients with Ulcerative Colitis.

Background: Histo-endoscopic outcomes are being proposed as new treatment targets in ulcerative colitis [UC]. Little is known about the pharmacokinetic-pharmacodynnamic [PK-PD] relationship of ustekinumab [UST] in UC patients or whether serum UST concentrations reflect tissue drug exposure. We aimed to study UST serum concentrations and their relation to tissue exposure and drug effectiveness in a real-world setting.

Development and validation of a microfluidic multiplex immunoassay for the determination of levels and avidity of serum antibodies to tetanus, diphtheria and pertussis antigens.

A multiplex assay for the quantitation of immunoglobulin G (IgG) serum antibodies directed against Clostridium tetani toxin (TT), Corynebacterium diphtheriae toxoid (DTxd), and the Bordetella pertussis antigens pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (Prn) was developed on an Evalution® platform to enhance the evaluation of the specific antibody response towards protein antigens in suspected humoral immunodeficiencies. Evalution® is a microfluidic and microparticle-based platform with the possibility to analyse single samples and to perform real-time kinetic measurements of antibody binding. All individual antigens were covalently linked to the carboxylated microparticles after which samples and fluorescently labelled detection antibodies were flowed over the microparticles in the microfluidic channels of the assay cartridges of the system.

Ustekinumab Dosing Individualization in Crohn's Disease Guided by a Population Pharmacokinetic-Pharmacodynamic Model.

Ustekinumab is a monoclonal antibody used in Crohn's disease (CD). Dose optimization in case of non-response and the role of pharmacokinetic-pharmacodynamic (PK-PD) monitoring remain unresolved dilemmas in clinical practice. We aimed to develop a population PK-PD model for ustekinumab in CD and simulate efficacy of alternative dosing regimens.

Collecting New Peak and Intermediate Infliximab Levels to Predict Remission in Inflammatory Bowel Diseases.

Background: The loss of response to infliximab is a challenge for clinicians in the management of inflammatory bowel disease (IBD). Mounting evidence suggests that therapeutic drug monitoring at induction may predict remission during maintenance. The aim of the study was to improve predictive models of remission by exploring new peak and intermediate infliximab measurements during induction.

The effect of aging on infliximab exposure and response in patients with inflammatory bowel diseases.

Aims: Controversies regarding infliximab treatment in elderly patients with inflammatory bowel diseases remain. We evaluated the effect of patient's age on infliximab exposure, efficacy and safety.

Methods: Retrospective case-control data of patients receiving infliximab induction treatment were analysed.

Tissue Exposure does not Explain Non-Response in Ulcerative Colitis Patients with Adequate Serum Vedolizumab Concentrations.

Background And Aims: Some patients with ulcerative colitis [UC] do not respond to vedolizumab treatment despite adequate drug exposure in serum. This study aimed to investigate vedolizumab in tissue and questioned whether insufficient tissue exposure could explain non-response in UC patients with adequate serum vedolizumab concentrations.

Methods: A paired serum sample and colonic mucosal biopsy was collected from 40 UC patients [20 endoscopic responders, 20 non-responders] at week 14 of vedolizumab treatment.

A Novel Tau Antibody Detecting the First Amino-Terminal Insert Reveals Conformational Differences Among Tau Isoforms.

As human Tau undergoes pathologically relevant post-translational modifications when expressed in yeast, the use of humanized yeast models for the generation of novel Tau monoclonal antibodies has previously been proven to be successful. In this study, human Tau2N4R-ΔK280 purified from yeast was used for the immunization of mice and subsequent selection of high affinity Tau-specific monoclonal antibodies. The characterization of four novel antibodies in different Tau model systems yielded a phosphorylation-dependent antibody (15A10), an antibody directed to the first microtubule-binding repeat domain (16B12), a carboxy-terminal antibody (20G10) and an antibody targeting an epitope on the hinge of the first and second amino-terminal insert (18F12).

Evaluating an easy sampling method using dried blood spots to determine vedolizumab concentrations.

An association between vedolizumab (VDZ) trough concentrations and therapeutic outcome has been observed in patients with inflammatory bowel diseases. VDZ samples are typically collected via venous sampling for therapeutic drug monitoring (TDM), but can alternatively be collected via dried blood spot (DBS) samples, which can be used for intensive sampling to investigate pharmacokinetic profiles. Therefore, we have developed a DBS method for determining VDZ concentrations and validated this method by comparing VDZ measurements in paired DBS and venous patient samples.

Peak Concentrations of Ustekinumab After Intravenous Induction Therapy Identify Patients With Crohn's Disease Likely to Achieve Endoscopic and Biochemical Remission.

Background & Aims: Little is known about the relationship between ustekinumab exposure during the first 2 weeks of treatment and outcomes of patients with Crohn's disease (CD). We investigated the relationship between serum concentrations of ustekinumab during the first 2 weeks of treatment and endoscopic and biochemical remission in patients with CD.

Methods: In a prospective observational study, we measured concentrations of ustekinumab in serum samples from 41 consecutive patients who started treatment with ustekinumab (approximately 6 mg/kg, intravenously, then 90 mg every 8 weeks), due to endoscopic markers of active CD, at a single center from October 2017 through January 2019.

Successful Infliximab Treatment is Associated With Reversal of Clotting Abnormalities in Inflammatory Bowel Disease Patients.

Background And Goals: Active inflammatory bowel diseases (IBD) represent an independent risk factor for venous thromboembolism. The authors investigated the hemostatic profile of IBD patients before and after induction treatment with infliximab, vedolizumab, and methylprednisolone.

Study: This prospective study included 62 patients with active IBD starting infliximab, vedolizumab, and/or methylprednisolone, and 22 healthy controls (HC).

Achieving Mucosal Healing in Inflammatory Bowel Diseases: Which Drug Concentrations Need to Be Targeted?

Biologicals introduced a major shift in the treatment of patients suffering from inflammatory bowel diseases. Despite providing a tight disease control for many patients, a considerable proportion of patients will fail to respond favorably to treatment or will lose response over time. Therapeutic drug monitoring emerged as a valuable tool to guide clinical decision making as serum drug concentrations have been linked to outcomes.