Background Takayasu's arteritis (TAK) is a chronic vasculitis of large-vessels, mainly affecs the aorta and its branches in middle-aged females. There are reports regarding the concurrence of inflammatory bowel disease (IBD) and TAK. Microscopic colitis (MC) has been demonstrated in inflammatory rheumatic diseases such as spondylarthropathies which has been linked to an ethiopathogenetical association between two diseases. MC as an IBD subgroup has not been investigated in TAK, so far.
Objectives To assess the presence of MC in TAK patients who have no clinically overt IBD symptoms.
Methods We cross-sectionally assessed TAK patients, between the ages of 18-65, who were diagnosed according to ACR criteria. Disease activity was evaluated by Kerr's criteria. Age and sex matched irritabl bowel syndrome (IBS) patients were selected as control group. Study subjects who have been on MC inducing medications, such as NSAIDs, PPI, anti-physchotic or anti-depressant and having co-morbidities were excluded. All patients and controls have been interviewed for IBD and IBS symptoms by the questionnaires of WHO guideline and Rome III criteria, respectively. Lower endoscopic procedure was performed with at least 5 random biopsies taken from different colonic segments and terminal ileum within the following 2 weeks after the research visit. A blinded expert pathologist evaluated the specimens for the thickness of the collagen band, the degree of inflammatory infiltration in the lamina propria, and the number of intraepithelial lymphocytes according to an algorythm proposed for MC assessment by Langner C et al (1). Lymphocytic and collagen colitis were defined as the subgroups of MC. Incomplete colitis has also been defined in the algorythm.
Results Thirteen TAK patients (13 female) with the mean age of 34±12 (20-59), total disease duration of 86±60 months (12-204) and 10 female IBS controls with the mean age of 38±13 were included into the study. Type 2 vascular involvement was the most common (62%) pattern in the cohort. Five of 13 (38%) TAK patients have active disease at the time of endoscopic procedure. No remarkable histopathological abnormality was demonstrated in any patients with IBS and 3 with TAK. All but one TAK patients had normal endoscopic findings. Erythema on the entire colonic mucosa as the only pathological endoscopic finding was demonstrated in one patient. The examination of terminal ileum was found normal in both TAK and control groups. Three patients (23%) were full-filled the LC criteria. Incomplete LC was determined in 2 of 13 patients (15%). Lymphoid hyperplasia (69%) was found as an additional abnormality which has not been a standart item in the assessment of MC.
Table 1: Clinical gut symptoms and histophatological findings of colonic mucosa in patients with TAK.
Conclusions Our preliminary results show that there is an increased frequency of MC in TAK patients who had no overt IBD symptoms/diagnosis. This preliminary report from our ongoing study supports that this association might have pathopyhsiological relevance and should be confirmed in a large cohort.
Langner C et al. Histology of microscopic colitis- review with a practical approach for pathologist. Histopathology 2014.
Disclosure of Interest None declared