Comparing Disease Characteristics between African-American and Caucasian Inflammatory Bowel Disease Patients

Abstract

Purpose: The incidence of inflammatory bowel disease (IBD) in non-caucasian minority groups, including African-Americans (AA), appears to be increasing but there is limited understanding of phenotypic differences and outcomes by race. Here we describe the disease characteristics of self-identified AA patients at the University of Chicago and compare them to the disease characteristics of caucasian patients.Figure: No Caption available.Methods: This was a retrospective review of the IBD registry at the University of Chicago, which captures all outpatients seen in the outpatient clinics. Data regarding self-identified race, IBD type, location, extent, surgery, family, and smoking history, medications, extraintestinal manifestations (EIMs), cancer and dysplasia history, and involvement in clinical trials were abstracted from the database. The data were then divided by race and compared via univariate chi-square analysis with a significance level of p< 0.10. Results: For Crohn's disease (CD) patients, 797 caucasians and 86 AA were identified. For ulcerative colitis (UC) patients, 345 caucasians and 19 AA were identified. Among CD patients, AA had significantly higher rates of joint symptoms (31.2% v. 20.1%, p=0.015) and pyoderma gangrenosum (3.5% v. 1.1%, p=0.073). AA CD patients had a significantly lower rate of ileal involvement (45.4% v. 60.4%, p=0.007), but no difference in rates of upper gastrointestinal, jejunal, colonic, or perianal disease. Among UC patients, AA had significantly higher rates of EIMs overall (42.1% v. 20.8%, p=0.029), joint symptoms (26.3% v. 12.1%, p=0.072), and pyoderma gangrenosum (5.3% v. 0.6%, p=0.028). There was no significant difference in disease extent. We also found no significant differences in medication usage, clinical trial enrollment, prevalence of dysplasia or cancer, surgical, family, or smoking histories between AA and caucasian patients for either disease. Conclusion: We describe one of the largest cohorts of AA IBD patients, and found several significant differences between these patients and caucasian IBD patients. In this study population, IBD EIMs are more common in AA patients compared to caucasians in both UC and CD. In addition, no racial disparities were detected in treatments or clinical trial enrollment. These findings can help clinicians understand their patients' disease better upon presentation and suggest genetic traits linked to racial phenotype underlying this difference in disease phenotype.Table: Disease location and extent