Clinical and histological predictors of response to medical therapy in collagenous colitis.

OBJECTIVES

Collagenous colitis (CC) is an uncommon form of inflammatory bowel disease. The response to typical medical therapies (antimotility agents, 5-aminosalicylic acid [5-ASA], and corticosteroids) is variable. We aimed to determine if there are clinical or histological variables that can predict response to medical therapy.

METHODS

All cases of CC were identified in three tertiary care medical centers. All charts of included patients were reviewed and clinical variables (age, gender, duration of symptoms, frequency of bowel movements, and the use of nonsteroidal anti-inflammatory drugs [NSAIDs]) were recorded. Available histology slides were reviewed by one GI pathologist. Intraepithelial inflammation, epithelial loss or detachment, inflammation in the lamina propria, presence of eosinophilia, crypt inflammation, Paneth's cell metaplasia, and collagen layer thickness were recorded. Depending on their response to therapy, patients were divided into three groups: 1) spontaneous recovery or response to antidiarrheal agents alone, 2) response to 5-ASA agents, and 3) response to corticosteroids after failure of antidiarrheal agents and 5-ASA.

RESULTS

Ninety-four patients with CC were identified. Of these, 62 patients were included. The median age was 58 (range = 20-85), and 88% were female. Among the histological parameters only the degree of inflammation in the lamina propria significantly differed between the three response groups (p = 0.007). Patients who required corticosteroids had greater inflammation. Among the clinical parameters age at presentation and use of NSAIDs significantly differed between groups. In the antidiarrheal group, patients tended to be more elderly, and in the corticosteroid group, more patients were on NSAIDs.

CONCLUSIONS

1. The degree of lamina propria inflammation can be used as a histological predictor to guide treatment in patients with CC. 2) Patients who responded to antidiarrheal agents or had spontaneous remissions were significantly older than those patients requiring 5-ASA compounds or corticosteroids. 3) Patients who were taking NSAIDs were more likely to require corticosteroid therapy, presumably reflecting more severe disease.