Segmental Histological Normalisation Occurs in Ulcerative Colitis but Does Not Improve Clinical Outcomes

Area of Science:

• Gastroenterology
• Inflammatory Bowel Disease
• Histopathology

Background:

• Complete histological normalization in ulcerative colitis (UC) correlates with better clinical outcomes.
• The clinical significance of partial, or segmental, histological normalization in UC is not well understood.

Purpose of the Study:

• To investigate the prevalence, patterns, predictors, and clinical outcomes associated with segmental histological normalization in patients with UC.

Main Methods:

• Retrospective analysis of medical records from 646 patients with confirmed UC and multiple colonoscopies.
• Segmental histological normalization defined as normalization in a specific bowel segment (rectum, left/right colon) previously showing chronic injury.
• Assessment of factors predicting segmental normalization and its association with clinical outcomes, including relapse-free survival.

Main Results:

• 32% of patients exhibited segmental histological normalization, while 10% achieved complete normalization.
• Segmental normalization was more common in current smokers and those diagnosed at age ≤16 years.
• Only complete histological normalization, not segmental, was associated with improved relapse-free survival (HR 0.23; p=0.008).

Conclusions:

• Segmental histological normalization is observed in a significant proportion of UC patients and is associated with specific risk factors.
• Segmental normalization alone does not indicate improved long-term clinical outcomes in ulcerative colitis patients.