Endoscopic alterations in Peyer's patches in patients with ulcerative colitis: A prospective, multicenter study

BACKGROUND AND AIM: Peyer's patches (PPs) play a major role in intestinal mucosal immunity; however, their role in ulcerative colitis (UC) is not well investigated. We evaluated endoscopic features of PPs on narrow-band imaging with magnifying endoscopy (NBI-ME) and investigated their association with clinical factors. METHODS: We prospectively recruited 105 patients with UC, 18 with Crohn's disease (CD), 16 with disease control (DC), and 33 healthy control (HC) subjects at 3 institutions from 2014 to 2017. NBI-ME images of the villi of PPs were evaluated according to the Villi Index, and patients were divided into the Villi Index low (L-) and high (H-) types. The 1-year sustained clinical remission rate was evaluated between L- and H-type PPs in patients with UC. RESULTS: The proportions of patients with H-type PPs were significantly higher among UC, CD, and DC patients than among HC patients (P = 0.0125, 0.018, 0.0007). In UC, age, gender, endoscopic score, and extent of disease involvement were not significantly different between L- and H-type PPs, whereas the sustained clinical remission rate was significantly higher in L-type PPs than in H-type PPs (88% [57/65] vs. 65% [17/26], P = 0.019). Multivariate analysis revealed that the L-type of PPs was a significant factor for sustained clinical remission (odds ratio 3.8, 95% confidence interval 1.1-12.9, P = 0.033). CONCLUSIONS: Patients with UC showed endoscopic alterations in PPs on NBI-ME, and highly altered appearance of PPs can be associated with a high risk of clinical relapse in patients with UC.