Publications by authors named "Tanja van Viegen"
Background: Regulatory guidance for Crohn's disease trials recommends coprimary efficacy end points that evaluate both symptoms and mucosal inflammation. We aimed to characterize the operating properties of commonly used disease activity assessments alone and in combination.
Methods: Endoscopic and clinical data were available for 129 participants from the Study of Biologic and Immunomodulator Naïve Patients in Crohn's Disease trial.
Aims: Accurate determination of histological activity in ulcerative colitis (UC) is essential given its diagnostic and prognostic importance. Data on the relationship between histology and immune cell markers are limited. We aimed to evaluate the association between histological disease activity and immune cell marker concentration in colonic biopsies from patients with UC.
View Article and Find Full Text PDFBackground: Clinical trials of novel therapies for the treatment of ulcerative colitis (UC) may benefit from immune cell profiling, however implementation of this methodology is limited in the multicenter trial setting by necessity of timely (within 6 to 8 h) isolation and processing of peripheral blood mononuclear cells (PBMC) from whole blood samples. Becton Dickinson Vacutainer CPT™ Cell Preparation Tubes (CPT™) limit required processing prior to shipping to a central lab to an initial centrifugation step within 24 h of sample collection. As shipping may delay final processing beyond 24 h, we analyzed cell viability and T cell composition in whole blood stored in CPT™ to determine if their use may accommodate processing delays typical for multicenter clinical trials.
View Article and Find Full Text PDFBackground: Development of bowel preparation products has been based upon colon cleansing rating by a local endoscopist. It is unclear how bowel preparation scales perform when centrally evaluated.
Aims: To evaluate the reliability of bowel preparation quality scales when assessed by central readers.
The T-lymphocyte-mediated inflammation in Crohn's disease can be assessed by quantifying CD3-positive T-lymphocyte counts in colonic sections. We developed and validated a process to reliably quantify immunohistochemical marker-positive cells in a high-throughput setting using whole slide images (WSIs) of CD3-immunostained colonic and ileal tissue sections. In regions of interest (ROIs) and/or whole tissue sections of 40 WSIs from 36 patients with Crohn's disease, CD3-positive cells were quantified by an expert gastrointestinal pathologist (gold standard) and by image analysis algorithms developed with software from 3 independent vendors.
View Article and Find Full Text PDFBackground & Aims: Magnetic resonance enterography (MRE) is having an increasing role in Crohn's disease; however, fully validated indices are needed. We evaluated the responsiveness of 4 MRE indices in luminal Crohn's disease.
Methods: Paired MRE images (pretreatment and post-treatment at weeks 12 or 14) from 41 patients were scored by 3 blinded radiologists.
Background: The optimal ulcerative colitis biopsy protocol is unclear.
Aim: To evaluate the number of biopsies required to accurately assess microscopic disease activity in ulcerative colitis METHODS: Biopsies from patients with ≥4 rectosigmoid samples, and clinical and endoscopic data, were retrospectively obtained from a prospective biobank. Histology and endoscopic videos were read blindly.
Background & Aims: Endoscopy is used to measure activity of Crohn's disease (CD) and determine eligibility and outcomes of participants in randomized controlled trials of therapeutic agents. We aimed to estimate the rate of response to placebo in trials, based on endoscopic evaluation of CD activity, and identify factors that affect this response.
Methods: We collected patient-level data from randomized, double-blind, placebo-controlled trials of therapeutic agents for CD that included centrally-read endoscopic assessments with validated scoring indices.
Background & Aims: There is no validated magnetic resonance imaging (MRI) index for assessment of perianal fistulas in patients with Crohn's disease (CD). We developed and internally validated a new instrument.
Methods: We used paired baseline and week-24 MRI scans from 160 participants in a randomized placebo-controlled trial of stem cell therapy for patients with perianal fistulizing CD.
Background: The appropriate location for biopsy procurement relative to an ulcer in active Crohn's disease is unknown.
Aim: To explore the relationship between biopsy location, histological disease activity, proinflammatory gene expression and the presence of inflammatory cells.
Methods: Fifty-one patients with Crohn's disease and ulcers >0.
Background: Flow cytometric (FC) analysis of intestinal tissue biopsies requires prompt cell isolation and processing to prevent cell death and generate valid data. We examined the effect of storage conditions prior to cell isolation and FC on viable cell yield and the proportions of immune cell phenotypes from intestinal biopsies.
Methods: Biopsies (N = 224) from inflamed or non-inflamed ileal and/or colonic tissue from three patients with Crohn's disease were processed and analyzed immediately in duplicate, or stored under different conditions.
Objectives: Flow cytometry (FC) aids in characterization of cellular and molecular factors involved in pathologic immune responses. Although FC has potential to facilitate early drug development in inflammatory bowel disease, interlaboratory variability limits its use in multicenter trials. Standardization of methods may address this limitation.
View Article and Find Full Text PDF