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Canadian Journal of Gastroenterology
Volume 25 (2011), Issue 5, Pages 269-273
Original Article

Assessing Inflammatory Bowel Disease-Associated Antibodies in Caucasian and First Nations Cohorts

Charles N Bernstein,1,2 Hani El-Gabalawy,2 Michael Sargent,1,2 Carol J Landers,4 Patricia Rawsthorne,1,2 Brenda Elias,3 and Stephan R Targan4

1IBD Clinical & Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
2Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
3Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
4Cedars Sinai Medical Center, Los Angeles, California, USA

Received 14 September 2010; Accepted 13 October 2010

Copyright © 2011 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


BACKGROUND: First Nation populations in Canada have a very low incidence of inflammatory bowel disease (IBD). Based on typical infections in this population, it is plausible that the First Nations react differently to microbial antigens with a different antibody response pattern, which may shed some light as to why they experience a low rate of IBD.

OBJECTIVE: To compare the positivity rates of antibodies known to be associated with IBD in Canadian First Nations compared with a Canadian Caucasian population.

METHODS: Subjects with Crohn’s disease, ulcerative colitis (UC), rheumatoid arthritis (RA) (as an immune disease control) and healthy controls without a personal or family history of chronic immune diseases, were enrolled in a cohort study aimed to determine differences between First Nations and Caucasians with IBD or RA. Serum from a random sample of these subjects (n=50 for each of First Nations with RA, First Nations controls, Caucasians with RA, Caucasians with Crohn’s disease, Caucasians with UC and Caucasians controls, and as many First Nations with either Crohn’s disease or UC as could be enrolled) was analyzed in the laboratory for the following antibodies: perinuclear antineutrophil cytoplasmic antibody (pANCA), and four Crohn’s disease-associated antibodies including anti-Saccharomyces cerevisiae, the outer membrane porin C of Escherichia coli, I2 – a fragment of bacterial DNA associated with Pseudomonas fluorescens, and the bacterial flagellin CBir-1. The rates of positive antibody responses and mean titres among positive results were compared.

RESULTS: For pANCA, First Nations had a positivity rate of 55% in those with UC, 32% in healthy controls and 48% in those with RA. The pANCA positivity rate was 32% among Caucasians with RA. The rates of the Crohn’s disease-associated antibodies for the First Nations and Caucasians were comparable. Among First Nations, up to one in four healthy controls were positive for any one of the Crohn’s disease-associated antibodies. First Nations had significantly higher pANCA titres in both the UC and RA groups than Caucasians

DISCUSSION: Although First Nation populations experience a low rate of IBD, they are relatively responsive to this particular antibody panel.

CONCLUSIONS: The positivity rates of these antibodies in First Nations, despite the low incidence of IBD in this population, suggest that these antibodies are unlikely to be of pathogenetic significance.