Mucosal Profiles of Immune Molecules Related to T Helper and Regulatory T Cells Predict Future Relapse in Patients with Quiescent Ulcerative Colitis

Background: T helper (Th)- and regulatory T (Treg) cell-related immune molecules are implicated in ulcerative colitis (UC). However, the association between their mucosal expression during remission and the subsequent clinical course of UC is unknown. Methods: The expression of cytokines and transcription factors related to Th1, Th2, Th17, and Treg in endoscopic mucosal biopsy specimens from 40 UC patients in clinical remission and 9 controls was measured by quantitative polymerase chain reaction. The relationship between their expression patterns, as stratified by Mayo Endoscopic Subscore (MES), and any future relapse was evaluated by univariate and multivariate analyses. Results: Six of 40 patients (baseline MES 0/1/2, 22/14/4) experienced a relapse during the study period (median, 37 months). At baseline, even in the MES0 patients, the interleukin (IL)-17A of the patients was significantly upregulated in comparison with controls (P = 0.0351). Future relapse was associated with a higher baseline expression of IL-17A, IL-17F, and IL-21 in MES0/1, and the upregulation of IL-17F and IL-21 remained statistically significant when limited to MES0 patients. Kaplan-Meier analysis revealed that as a single marker, a higher IL-21 level best grouped patients with an increased risk of relapse (P = 0.0042). Furthermore, a multivariate model that consisted of IL-21 and T-bet showed an even greater value (P = 0.0001). Conclusions: The profiles of Th/Treg-related gene expression in the colonic mucosa are altered, even during clinical and endoscopic remission of UC, with a detectable Th17-predominant profile predicting future relapse. This association might represent latent immune dysregulation during disease quiescence and has the potential to be utilized to improve patient care.