Arthritis and IBD //
Partnering with Dr Hani El-Gabalawy of the Manitoba Arthritis Centre, and supported by national funding from the Canadian Institutes of Health Research from 2007-2010, we explored the differences and similarities between two inflammatory conditions, rheumatoid arthritis and inflammatory bowel disease, in First Nations and Caucasian (white) individuals.
Rheumatoid arthritis is an immune disease of the joints and is treated with many of the same drugs used to treat IBD. Dr El-Gabalawy had been studying risk factors for rheumatoid arthritis, especially in individuals of indigenous backgrounds in Manitoba. First Nations people have much higher rates of rheumatoid arthritis than Caucasians, and much lower rates of IBD, for reasons that are not clear, but which may give clues to these two diseases.
What did we do?
We had nearly 1700 participants from Manitoba in this study who contributed surveys and blood for DNA and serum. We contrasted genetic and serum markers in persons with rheumatoid arthritis compared to persons with IBD; and among persons who were First Nation versus those who were white.
What did we find?
We found that persons of First Nations descent who had no chronic immune diseases like rheumatoid arthritis or IBD were not very likely to have the genetic mutations associated with IBD that have been seen in the Caucasian population. However, we found other gene mutations in some immune pathways to be higher in the First Nations group. These findings suggested that the low rate of IBD among First Nations individuals may be partly explained by their genetic make up.
Murdoch TB, Bernstein CN, El-Gabalawy H, Stempak JM, Sargent M, Elias B, Xu W, Pathan S, Silverberg MS. Prevalence of genetic variants associated with inflammatory bowel disease in healthy First Nations and Caucasian cohorts. Canadian Medical Association Journal 2012; 184: 435-41.
We also found that healthy First Nations individuals were more likely to have antibodies to some of the markers we associate with IBD, making these tests less useful as diagnostic tests in First Nations, if checking for IBD.
Bernstein CN, El-Gabalawy H, Sargent M, Rawsthorne P, Landers C, Elias B, Targan SR. Assessing IBD-associated antibodies in Caucasian and First Nation cohorts. Canadian Journal of Gastroenterology 2011; 25: 269-73.
We compared background factors like age and sex, as well as oral health (health of teeth and gums) between the First Nation and Caucasian populations, because other studies were suggesting a certain bug that lives in the gums, called P gingivalis, could be associated with rheumatoid arthritis. We found that persons of First Nations descent had poorer oral hygiene and were more likely to smoke than Caucasians, and that lifestyle factors like smoking negatively affected oral health. Since IBD is not common in First Nations people, we wondered whether poorer oral health was protective against the development of IBD, but we did not get a clear answer in these studies.
Blanchard AK, Wang X, El-Gabalawy H, Tan Q, Orr P, Elias B, Rawsthorne P, Hart D, Chubey S, Bernstein CN. Oral health in a First Nations and a non-Aboriginal population in Manitoba. International Journal of Circumpolar Health 2012; 71: 17394.