Endoscopic and histologic healing distribution and persistent rectosigmoiditis in moderate-to-severe ulcerative colitis.

BACKGROUND

Mucosal healing in ulcerative colitis (UC) is believed to follow a proximal-to-distal pattern. We evaluated colonic healing distribution in patients with moderate-to-severe UC receiving adalimumab.

METHODS

Patients from the SERENE UC (Study of a Novel Approach to Induction and Maintenance Dosing with Adalimumab in Patients with Moderate to Severe Ulcerative Colitis) trial with full colonoscopies and segmental biopsies at screening, weeks 8, and 52 were included for endoscopic and histologic analyses if baseline Mayo endoscopic subscore (MES) or Robarts Histopathology Index (RHI) score, respectively, was >0 in the ascending, transverse, and/or descending colon. Data were analyzed using a mixed model for repeated measures to account for clustering of segments within a patient.

RESULTS

Endoscopic and histologic analyses comprised 76 and 79 patients, respectively. Score reductions were significantly greater vs the rectum in the ascending (week 8: MES, mean -0.78 [95% confidence interval (CI), -1.03 to -0.52]; RHI, mean -4.70 [95% CI, -6.92 to -2.49]; week 52: MES, mean -0.63 [95% CI, -0.91 to -0.35]; RHI, mean -2.39 [95% CI, -4.64 to -0.15]), transverse (week 8: MES, mean -0.69 [95% CI, -0.94 to -0.43]; RHI, mean -3.57 [95% CI, -5.62 to -1.51]; week 52: MES, mean -0.64 [95% CI, -0.89 to -0.38]; RHI, mean -2.88 [95% CI, -4.99 to -0.77]), and descending colon (week 8: MES, mean -0.40 [95% CI, -0.67 to -0.13]; RHI, mean -2.55 [95% CI, -4.94 to -0.16]; week 52: MES, mean -0.52 [95% CI, -0.70 to -0.34]; RHI, mean -3.47 [95% CI, -5.37 to -1.56]). Endoscopic improvement/remission and histologic remission were significantly more likely in the ascending and transverse colon than the rectum.

CONCLUSIONS

Our findings demonstrate that endoscopic and histologic healing is more challenging in the rectum compared with proximal colonic segments.