TRANS-CONTINENTAL ANALYSIS OF OVER 2,000 INFLAMMATORY BOWEL DISEASE PATIENTS IMPLICATES GEOGRAPHY, DISEASE TYPE, AND EXPOSURE TO IMMUNOSUPPRESSION AS DRIVERS OF SARS-COV-2 SEROPREVALENCE

ABSTRACT

Background: 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 SARSCoV- 2 sero-surveillance of IBD patients prior to vaccination at seven large tertiary centres in Asia, Europe, and North America. Methods: Clinical data and sera were collected from 2,241 IBD patients receiving routine care at institutions in Belgium, Canada, Hong Kong, India, Japan, United Kingdom, and the United States between May 2020 and September 2021 (Table 1). Sera were taken prior to vaccination. Clinical data were collected from 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. We performed univariate analysis to evaluate association between variables and sero-status. Results: The pre-vaccination seroprevalence of antibodies to SARS-CoV-2 in IBD patient varied widely according to location from 0% in Hong Kong, China, to 57.9% in New Delhi, India. Rates in Europe and North America were similar (range 3.6%-8.9%). Overall, SARSCoV- 2 seroprevalence appears to be equal to or less than local populations (Table 1). Seroprevalence rates were associated with IBD type (Crohn's disease 7.8%, ulcerative colitis 12.4%, IBD-unclassified 15.0%, p<0.001), smoking status (p<0.001), and history of COVID diagnosis (p<0.001) or COVID hospitalization (p=0.001), and any immunomodulator (IMM) (p<0.001) (Table 1). Infection as indicated by seropositivity in the absence of known COVID infection occurred in 7.3% of patients. Whilst there were no significant differences in seroprevalence between patients receiving anti-tumor necrosis factor (anti-TNF) medications, vedolizumab (VDZ), and ustekinumab (UST), antibody levels were attenuated in patients on anti-TNF monotherapy (p=0.002), anti-TNF + IMM combination therapy (p=0.002), and VDZ (p=0.02), compared with no medications (Figure 1). Conclusion: We confirm in diverse populations that exposure to anti-TNFs, vedolizumab and 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. (Table Presented) Table 1. Seroprevalence of total anti-SARS-CoV-2 spike antibodies in IBD patients by ICARUS centre with non-IBD controls noted for New Delhi, India, and publicly reported local seroprevalence and by selected patient characteristics.(Figure Presented) Figure 1. Antibody levels by medication group.