Racial Differences in Fistulizing Perianal Crohnʼs Disease

Abstract

Purpose: Perianal disease is noted in up to one-third of patients with Crohn's disease (CD). In 2005, the Montreal Classification recognized that fistulizing perianal disease (FPD) represents a distinct phenotype from enteric fistulization. A growing body of literature suggests that there might be racial variations in the phenotypic manifestations of CD but different studies have reached conflicting conclusions and few if any have specifically focused on perianal disease in adults with pre-specified criteria of severity. The goal of our study was therefore to explore racial differences in the prevalence of severe fistulizing perianal Crohn's disease. Methods: We conducted a cross-sectional study of all adult patients with Crohn's disease treated with Remicade® at The Mount Sinai Hospital between May 1 and December 31, 2011. We retrieved the electronic and/or paper charts of all 363 CD patients who had received Remicade® at our institution. Each chart was reviewed to confirm the diagnosis and features of CD based on gastroenterologists' notes and colonoscopy and pathology reports. Variables recorded included age, sex, self-reported race, and presence or absence of notation of FPD. Proportions of patients with FPD noted among AA vs. others, and among Caucasians vs. others were compared using Pearson chi square analysis. P-value <0.05 was considered statistically significant. Results: Among all 333 evaluable CD patients on Remicade®, 73.6% were Caucasian, 11.4% AA, 13.2% Hispanic, and 1.8% Asian. Of these 333 patients, 88 had FPD. 48 of the FPD group (54.5%) were Caucasian, 18 (20.5%) were AA, 20 (22.7%) were Hispanic, and 2 (2.3%) were Asian. Thus, AA were more likely to have FPD than others (RR =1.87, 95% CI =1.18-2.65, p=0.004), while Caucasians were correspondingly less likely to have FPD than non-whites (RR =0.49, 95% CI= 0.35-0.70, p <0.0001). Conclusion: In agreement with some prior suggestions (e.g., J Pediatric Gastroenterol Nutr 1995;21:149-53 and Am J Gastroenterol 2009;104:2100-9) but not with others (e.g., Inflamm Bowel Dis 2006;12:192-8 and Inflamm Bowel Dis 2008;14:960-7), African-Americans with Crohn's disease are significantly more likely than others, and Caucasians significantly less likely, to have severe fistulizing perianal disease.