Publications by authors named "Pfefferkorn M"

Background & Aims: HBsAg proteins are useful to identify HBV inactive carriers (ICs), but data on chronic hepatitis D (CHD) are scarce. This study aimed to describe HBsAg composition in CHD, its changes during the evolution, and the potential association with clinical outcomes. In addition, we assess the composition of HBsAg across different HBV genotypes and validate previous results on HBsAg proteins in an independent HBV cohort.

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Background And Aims: We aimed to determine whether a targeted gene expression panel could predict clinical outcomes in paediatric ulcerative colitis [UC] and investigated putative pathogenic roles of predictive genes.

Methods: In total, 313 rectal RNA samples from a cohort of newly diagnosed paediatric UC patients (PROTECT) were analysed by a real-time PCR microfluidic array for expression of type 1, 2 and 17 inflammation genes. Associations between expression and clinical outcomes were assessed by logistic regression.

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Article Synopsis
  • - The study investigates the use and effectiveness of antitumor necrosis factor (TNF) biologics in young children diagnosed with very early onset inflammatory bowel disease (VEOIBD) across 25 North American centers from 2008 to 2013, aiming to track treatment initiation and durability over time.
  • - Out of 294 children with VEOIBD, 120 started anti-TNF therapy, with a 90% treatment durability at 1 year, which declined to 55% by 5 years, and loss of response was the main reason for discontinuation.
  • - The research found that children with Crohn disease had a significantly higher treatment durability than those with ulcerative colitis or IBD unclassified
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Background: Proactively monitoring infliximab levels is an emerging area of interest in pediatric Crohn's disease. There are only limited data on therapeutic drug monitoring for children with Crohn's disease. The goal of our study was to determine the utility of therapeutic drug monitoring in achieving clinical remission in a cohort of pediatric Crohn's disease patients receiving infliximab.

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Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene.

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An important goal of clinical genomics is to be able to estimate the risk of adverse disease outcomes. Between 5% and 10% of individuals with ulcerative colitis (UC) require colectomy within 5 years of diagnosis, but polygenic risk scores (PRSs) utilizing findings from genome-wide association studies (GWASs) are unable to provide meaningful prediction of this adverse status. By contrast, in Crohn disease, gene expression profiling of GWAS-significant genes does provide some stratification of risk of progression to complicated disease in the form of a transcriptional risk score (TRS).

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Objectives: Inadequate bowel preparation (IBP) for colonoscopy leads to missed diagnosis, longer anesthesia time, higher chance of complications and increased costs. Adult studies have demonstrated that patient characteristics such as male gender and obesity are associated with IBP. Little is known about factors affecting bowel preparation in children.

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TBase is an electronic health record (EHR) for kidney transplant recipients (KTR) combining automated data entry of key clinical data (e.g., laboratory values, medical reports, radiology and pathology data) via standardized interfaces with manual data entry during routine treatment (e.

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Background: Develop a clinical and biological predictive model for colectomy risk in children newly diagnosed with ulcerative colitis (UC).

Methods: This was a multicenter inception cohort study of children (ages 4-17 years) newly diagnosed with UC treated with standardized initial regimens of mesalamine or corticosteroids (CS) depending upon initial disease severity. Therapy escalation to immunomodulators or infliximab was based on predetermined criteria.

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The MACCS (Medical Assistant for Chronic Care Service) platform enables secure sharing of key medical information between patients after kidney transplantation and physicians. Patients provide information such as vital signs, well-being, and medication intake via smartphone apps. The information is transferred directly into a database and electronic health record at the kidney transplant center, which is used for routine patient care and research.

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Background: Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures.

Materials And Methods: Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN.

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Background & Aims: During treatment of chronic HBV infections, loss or seroconversion of the HBV surface antigen (HBsAg) is considered a functional cure. HBsAg consists of the large (LHBs), middle (MHBs), and small surface protein (SHBs) and their relative proportions correlate strongly with disease stage. Our aim was to assess the association between HBsAg composition and functional cure during treatment.

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Background: The incidence of very early onset inflammatory bowel disease (VEOIBD) is increasing, yet the phenotype and natural history of VEOIBD are not well described.

Methods: We performed a retrospective cohort study of patients diagnosed with VEOIBD (6 years of age and younger) between 2008 and 2013 at 25 North American centers. Eligible patients at each center were randomly selected for chart review.

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Hepatitis B virus (HBV) RNA in serum is a novel biomarker that reflects cccDNA activity. We investigated whether HBV RNA can predict serological response to peginterferon (PEG-IFN) treatment. Serum HBV RNA levels were retrospectively measured at weeks 0, 12, 24 and 52 of therapy and after treatment discontinuation (week 78) in 266 HBeAg-positive chronic HBV patients who had participated in a global randomized controlled trial (HBV99-01 study).

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Background: Hepatitis B virus RNA (HBV-RNA) is a novel serum biomarker that correlates with transcription of intrahepatic covalently closed circular (cccDNA), which is an important target for pegylated interferon (PEG-IFN) and novel therapies for functional cure. We studied HBV-RNA kinetics following PEG-IFN treatment and its potential role as a predictor to response in HBeAg-negative chronic hepatitis B (CHB) patients.

Methods: HBV-RNA levels were measured in 133 HBeAg-negative CHB patients treated in an international randomized controlled trial (PARC study).

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Background: Lack of evidence-based outcomes data leads to uncertainty in developing treatment regimens in children who are newly diagnosed with ulcerative colitis. We hypothesised that pretreatment clinical, transcriptomic, and microbial factors predict disease course.

Methods: In this inception cohort study, we recruited paediatric patients aged 4-17 years with newly diagnosed ulcerative colitis from 29 centres in the USA and Canada.

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Molecular mechanisms driving disease course and response to therapy in ulcerative colitis (UC) are not well understood. Here, we use RNAseq to define pre-treatment rectal gene expression, and fecal microbiota profiles, in 206 pediatric UC patients receiving standardised therapy. We validate our key findings in adult and paediatric UC cohorts of 408 participants.

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Background: Variation in care is common in medical practice. Reducing variation in care is shown to improve quality and increase favorable outcomes in chronic diseases. We sought to identify factors associated with variation in care in children with newly diagnosed Crohn's disease (CD).

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Evaluating progression risk and determining optimal therapy for ulcerative colitis (UC) is challenging as many patients exhibit incomplete responses to treatment. As part of the PROTECT (Predicting Response to Standardized Colitis Therapy) Study, we evaluated the role of the gut microbiome in disease course for 405 pediatric, new-onset, treatment-naive UC patients. Patients were monitored for 1 year upon treatment initiation, and microbial taxonomic composition was analyzed from fecal samples and rectal biopsies.

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Objectives: Environmental factors play an important role in the pathogenesis of Crohn's Disease (CD). In particular, by virtue of the instability of the microbiome and development of immunologic tolerance, early life factors may exert the strongest influence on disease risk and phenotype.

Methods: We used data from 1119 CD subjects recruited from RISK inception cohort to examine the impact of early life environment on disease progression.

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Background: In contrast to pediatric Crohn's disease (CD), little is known in pediatric ulcerative colitis (UC) about the relationship between disease phenotype and serologic reactivity to microbial and other antigens.

Aim: The aim of this study was to examine disease phenotype and serology in a well-characterized inception cohort of children newly diagnosed with UC during the PROTECT Study (Predicting Response to Standardized Pediatric Colitis Therapy).

Methods: Patients were recruited from 29 participating centers.

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Background: The genetic contributions to pediatric onset ulcerative colitis (UC), characterized by severe disease and extensive colonic involvement, are largely unknown. In adult onset UC, Genome Wide Association Study (GWAS) has identified numerous loci, most of which have a modest susceptibility risk (OR 0.84-1.

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