P520. Demographic features and long-term follow up outcome comparisons between patients with solo inflammatory bowel disease vs. inflammatory bowel disease and concomitant ankylosing spondylitis
Y. Erzin1, H. Eyvazov2, I. Hatemi1, G. Hatemi3, A.F. Celik1, 1Istanbul University Cerrahpasa Medical Faculty, Gastroenterology, Istanbul, Turkey, 2Istanbul University Cerrahpasa Medical Faculty, Internal Medicine, Istanbul, Turkey, 3Istanbul University Cerrahpasa Medical Faculty, Rheumatology, Istanbul, Turkey
Aim of the study was to compare demographic features and the long term patient outcomes between inflammatory bowel disease (IBD) patients with and without ankylosing spondylitis (AS).
An IBD clinic is run by our team since 1999 currently with 705 CD, 935 UC patients under the same registry. These patients' files retrospectively were evaluated and 76 patients with IBD+AS [49 with Crohn's disease (CD), 27 with ulcerative colitis (UC)] were identified and then each IBD+AS patient randomly was matched with the next two adjacent solo IBD patient with the same diagnosis so having 152 IBD (98 CD, 54 UC) patients as the control group. Besides comparing demographic features, the primary endpoint was to compare the rate of intestinal resections between both groups. Age at IBD and/or AS onset, age (if there is any) at resection, the mean follow up time, number of flares needing steroids, medications including the type, dosage and duration, presence of family history, sex, disease location, and behavior, presence of perianal fistulae, smoking status were noted. Patients with indeterminate colitis or AS patients developing intestinal inflammation under NSAID or biologic treatment were excluded.
AS significantly was more common in patients with CD (6.9%) than in patients with UC (2.8%) (p = 0.0001). Among 76 patients with IBD+AS, 52 (68%) first presented with IBD, 11 (15%) with AS, and the remaining 13 (17%) had both diagnoses at the same time. The mean age, age at diagnosis or at resection did not disclose any significant difference between both groups. Neither location nor behavior of IBD nor rate of perianal fistulae were different. The mean follow up time was significantly longer in patients with IBD+AS (44.49 vs 28.6 mo; p = 0.0011), and the use of biologics, steroids significantly were more common among patients with IBD+AS (37% vs. 9% for biologics, p = 0.000; 43% vs. 28% for steroids, p = 0.026). 33 out of 152 (22%) IBD and 11 out of 76 (14%) IBD+AS patients underwent an intestinal resection (total colectomy for UC, resection for CD) during our follow up (p = NS). The Spearman correlation test identified significant relations between IBD duration, frequency of flares needing steroids and resection, but an age-sex adjusted regression analysis disclosed IBD duration as the only independent predictor for resection (R2 = 0.178; p = 0.016).
The present study shows that up to 5% of IBD patients may have AS although it is twice more common in CD compared to UC patients. Patients with IBD+AS do not have a worse disease outcome than solo IBD patients. When both groups are analyzed together the only independent predictor for resection is the duration of IBD.