P342 Trans-continental analysis of over 2000 Inflammatory Bowel Disease patients implicates geography, disease type, and exposure to immunosuppression as drivers of SARS-CoV-2 seroprevalence: data from the ICARUS-IBD Consortium

Wong, S.Y.(1);Helmus, D.(2);Marlow, L.(3);Martinez Pazos, V.(2);Brann, S.(3);Wellens, J.(4);Kedia, S.(5);Mak , J.W.Y.(6);Bergemalm, D.(7);Argollo, M.(8);Zaltman, C.(9);Steinwurz, F.(10);Rubin, D.(11);Allez, M.(12);Halfvarson, J.(7);Abreu, M.T.(13);Lindsay, J.(14);Dutta, U.(15);Silverberg, M.S.(16);Ng, S.C.(6);Ahuja, V.(5);Watanabe, K.(17);Vermeire, S.(18);Colombel, J.F.(2);Satsangi, J.(19);

(1)Mount Sinai Hospital, The Henry D. Janowitz Division of Gastroenterology- Department of Medicine, New York, United States;(2)Icahn School of Medicine at Mount Sinai, The Henry D. Janowitz Division of Gastroenterology- Department of Medicine, New York, United States;(3)University of Oxford, Translational Gastro-Intestinal Unit- Nuffield Department of Medicine, Oxford, United Kingdom;(4)University Hospitals Leuven, Translational Research for Gastrointestinal Diseases, Leuven, Belgium;(5)All India Institute of Medical Sciences, Gastroenterology, New Delhi, India;(6)The Chinese University of Hong Kong, Medicine and Therapeutics, Hong Kong, China;(7)Örebro University, Dept of Gastroenterology- Faculty of Medicine and Health, Örebro, Sweden;(8)Universidade Federal de São Paulo, Department of Gastroenterology, São Paulo, Brazil;(9)Hospital Universitário- Universidade Federal Do Rio de Janeiro, Departamento de Clínica Médica, Rio de Janeiro, Brazil;(10)Instituto Steinwurz de Saúde do Intestino, Division of Gastroenterology and Hepatology, São Paulo, Brazil;(11)The University of Chicago, Gastroenterology- Hepatology & Nutrition, Chicago, United States;(12)Hôpital Saint-Louis- APHP- Université de Paris, Gastroenterology, Paris, France;(13)University of Miami Miller School of Medicine, Gastroenterology- Department of Medicine, Miami, United States;(14)Barts Health NHS Trust – The Royal London Hospital, Centre for Immunobiology, London, United Kingdom;(15)Postgraduate Institute of Medical Education & Research, Gastroenterology, Chandigarh, India;(16)University of Toronto, Division of Gastroenterology- Mount Sinai Hospital Inflammatory Bowel Disease Centre, Toronto, Canada;(17)Hyogo College of Medicine, Center for Inflammatory Bowel Disease- Division of Internal Medicine, Nishinomiya, Japan;(18)University Hospital Leuven and Catholic University Leuven, Gastroenterology & Hepatology, Leuven, Belgium;(19)University of Oxford, Nuffield Department of Medicine, Oxford, United Kingdom; ICARUS-IBD Consortium


IBD patients on immune-modulatory therapies are considered high-risk for SARS-CoV-2 infection. Direct comparisons of serological responses to SARS-CoV-2 infection in IBD patients across different continents and medications are lacking. We performed SARS-CoV-2 sero-surveillance of IBD patients prior to vaccination at seven large tertiary centres in Asia, Europe, and North America.


Clinical data and sera were collected from 2,213 IBD patients receiving routine care at institutions in Belgium, Canada, Hong Kong, India, Japan, the United Kingdom, and the United States between 26 May 2020 and 24 September 2021 (Table 1). Sera were taken prior to vaccination. Clinical data were collected through patient questionnaires and medical records. Antibody reactivity to the SARS-CoV-2 spike protein was assessed using the Roche SARS-CoV-2 anti-spike total antibody and/or Siemens Healthineers COV2T anti-spike total antibody assays, which showed 99.4% concordance. Univariate analysis was performed to evaluate association between individual variables and sero-status.


The pre-vaccination seroprevalence of antibodies to SARS-CoV-2 in IBD patient varied widely according to location from 0% in Hong Kong to 57.9% in New Delhi, India (p<0.001). Rates in Europe and North America were similar (range 3.57%-8.94%). Overall, SARS-CoV-2 seroprevalence appears to be equal to or less than local populations (Table 2). Seroprevalence rates were associated with IBD type (7.8% CD, 12.4% UC, 15% IBD-U, p<0.001), smoking status (p<0.001), and history of COVID diagnosis (p<0.001) or COVID hospitalization (p=0.001), and any IMM (p<0.001). (Table 3). Whilst there were no significant differences in seroprevalence between  patients receiving infliximab (IFX), vedolizumab (VDZ), and ustekinumab (UST), antibody levels were attenuated in patients on  IFX monotherapy and combination therapy (both p=0.002) and VDZ (p=0.02), compared with no medications (Figure 1).


We confirm in diverse poulations that exposure to biologics or immunomodulators, type of disease, and smoking status are associated with seroprevalence and antibody levels. We show for the first time the dominant influence of geographical location on sero-status in these patients. These observations should be considered as we look towards post-vaccination data to help stratify patients for clinical guidelines on SARS-CoV-2 vaccination.