Mallory Chavannes

Dr. Mallory Chavannes

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 July 2025 in Journal of Crohn's and Colitis
Verified
Journal Article
Closed access
TKTorsten Kucharzik
Torsten Kucharzik
STStuart Taylor
Stuart Taylor
MAMariangela Allocca
Mariangela Allocca
JBJohan Burisch
Johan Burisch
PEPierre Ellul
Pierre Ellul
RFRoger Feakins
Roger Feakins
The current consensus guideline offers a comprehensive and practical guidance on the diagnostic and monitoring of patients with inflammatory bowel disease (IBD). It provides recommendations on requirements for initial diagnosis, detection of complications, the use of monitoring tools in patients with IBD and diagnostics in specific situations, such as pregnancy, postoperatively and for cancer surveillance. The guideline is a joint project of the European Crohn’s and Colitis Organization (ECCO), the European Society of Gastrointestinal and Abdominal Radiology, the European Society of Pathology, and the International Bowel Ultrasonography Group under the leadership of ECCO.

10 July 2024 in Clinical Gastroenterology and Hepatology
Verified
Journal Article
Closed access
MCMallory Chavannes
Mallory Chavannes
MDMichael Todd Dolinger
Michael Todd Dolinger
SCShirley Cohen-Mekelburg
Shirley Cohen-Mekelburg
BABincy Abraham
Bincy Abraham

3 July 2025 in Journal of Crohn's and Colitis
Verified
Journal Article
Closed access
HYHenit Yanai
Henit Yanai
RFRoger Feakins
Roger Feakins
MAMariangela Allocca
Mariangela Allocca
JBJohan Burisch
Johan Burisch
PEPierre Ellul
Pierre Ellul
I[International Bowel Ultrasonography Group [IBUS]
International Bowel Ultrasonography Group [IBUS]

10 June 2019 in Journal of Crohn's and Colitis
Verified
Journal Article
Closed access
LHLara Hart
Lara Hart
MCMallory Chavannes
Mallory Chavannes
OKOmar Kherad
Omar Kherad
CMChelsea Maedler
Chelsea Maedler
NMNathalie Mourad
Nathalie Mourad
TBTalat Bessissow
Talat Bessissow
Introduction: Faecal calprotectin [FC] is a reliable surrogate marker for disease activity in ulcerative colitis [UC]; however, there are no consensus cut-off values for remission. The study aim was to correlate FC with Mayo Endoscopic Score [MES] and histological disease activity of UC patients in clinical remission.Methods: Our study recruited adult UC patients at the McGill IBD Center between 2013 and 2017. Patients in clinical remission [partial Mayo score ≤2], undergoing endoscopy for disease activity or dysplasia surveillance, were enrolled. Before bowel preparation, FC was collected. MES was documented during colonoscopy. Biopsies were taken; histological activity was assessed using Geboes score and the presence of basal plasmacytosis.Results: A total of 185 patients were recruited. The area under the curve [AUC] in receiver operating characteristic [ROC] analysis to predict MES 1–3 [from 0] was 0.743 [95% CI 0.67–0.82; p <0.001] with an FC cut-off value 170 µg/g [64% sensitivity, 74% specificity], and to predict MES 2–3 [from 0–1] was 0.722 [95% CI 0.61–0.83; p <0.001] with an FC cut-off value 170 µg/g [69% sensitivity, 65% specificity]. To differentiate MES 0 from MES 1, an FC value 130 µg/g yields a 70% sensitivity and 68% specificity. The AUC in ROC analysis to predict Geboes <3.1 was 0.627 [95% CI 0.55–0.71; p = 0.003], with an FC value 135 µg/g [54% sensitivity, 69% specificity].Conclusions: In this large study, FC ≥170 µg/g predicts endoscopic activity and FC ≥135 µg/g predicts histological activity. Therefore in clinical practice, lower faecal calprotectin thresholds can be chosen to optimise identification of patients with ongoing endoscopic and histological disease activity.

12 December 2018 in Journal of Crohn's and Colitis
Verified
Journal Article
Closed access
MCMallory Chavannes
Mallory Chavannes
CMChristine Martinez-Vinson
Christine Martinez-Vinson
LHLara Hart
Lara Hart
NKNicole Kaniki
Nicole Kaniki
CCChe-Yung Chao
Che-Yung Chao
ESErnest G Seidman
Ernest G Seidman
Ustekinumab [UST] is effective in the treatment of adults with moderate to severe Crohn's disease [CD]. There is a paucity of data on its use in children. To evaluate the response to UST in children with moderate to severe CD. This multicentre retrospective cohort study identified children under 18 years old with CD, who received open-labelled subcutaneous UST. The primary outcome was changes in mean abbreviated Paediatric Crohn's Disease Activity Index [aPCDAI] between baseline and 3 and 12 months, and rate of clinical remission at 3 and 12 months. Secondary outcomes were clinical response at the same time points, changes in C-reactive protein [CRP] and albumin, improvement in growth parameters, and rate of adverse events. A total of 44 patients who failed at least one biological treatment were identified. Linear mixed model [LMM] analysis revealed a statistically significant effect of UST (χ2[1] = 42.7, p = 1.2 × 10-8) which lowered the aPCDAI scores by about 16 ± 2.7 at 3 months, and 19.6 ± 2.9 at 12 months. At 12 months, 38.6% of the patients achieved clinical remission and 47.8% achieved clinical response. There was a significant increase in mean weight z-score of 0.48 [±0.13] [p <0.001] and in mean body mass index [BMI] z score of 0.66 [±0.16] [p <0.001]. The probability of remaining on UST at 12 months was 76.9%. The rate of adverse events was 12.4 per 1000 patient-months. Subcutaneous UST should be considered a viable therapeutic option for paediatric patients who are refractory to other biological agents. Prospective randomised trials are needed.

21 December 2021 in Nutrients
Verified
Journal Article
Open access
PDF file
LHLara Hart
Lara Hart
CVCharlotte Verburgt
Charlotte Verburgt
EWEytan Wine
Eytan Wine
MZMary Zachos
Mary Zachos
APAlisha Poppen
Alisha Poppen
NPNikhil Pai
Nikhil Pai
Inflammatory bowel disease (IBD) is a chronic, autoimmune disorder of the gastrointestinal tract with numerous genetic and environmental risk factors. Patients with Crohn’s disease (CD) or ulcerative colitis (UC) often demonstrate marked disruptions of their gut microbiome. The intestinal microbiota is strongly influenced by diet. The association between the increasing incidence of IBD worldwide and increased consumption of a westernized diet suggests host nutrition may influence the progression or treatment of IBD via the microbiome. Several nutritional therapies have been studied for the treatment of CD and UC. While their mechanisms of action are only partially understood, existing studies do suggest that diet-driven changes in microbial composition and function underlie the diverse mechanisms of nutritional therapy. Despite existing therapies for IBD focusing heavily on immune suppression, nutrition is an important treatment option due to its superior safety profile, potentially low cost, and benefits for growth and development. These benefits are increasingly important to patients. In this review, we will describe the clinical efficacy of the different nutritional therapies that have been described for the treatment of CD and UC. We will also describe the effects of each nutritional therapy on the gut microbiome and summarize the strength of the literature with recommendations for the practicing clinician.