Changes in the Lémann Index Values During the First Years of Crohn's Disease

Background & aims: Stricturing or penetrating lesions develop over time in most patients with Crohn's disease. The Lémann Index indicates the degree of digestive damage at a given time in an individual. We tracked changes in Lémann Index scores in an inception cohort of patients and looked for factors associated with digestive damage.

Methods: We studied 221 patients diagnosed with Crohn's disease from 2004 through 2011 who received 2 or 3 serial morphologic evaluations over a period of 2 to 10 years. We collected cross-sectional images and had them reviewed by a gastroenterologist and a radiologist; Lémann index scores were calculated. A value of 2 was chosen as the cut-off value for substantial transparietal damage. Factors associated with a score greater than 2 at the last evaluation and progression of index scores were identified using univariate analysis and logistic regression analyses.

Results: The median index Lémann Index scores were 2.3 (interquartile range [IQR], 1.2-3.9) at first evaluation, 3.5 (IQR, 1.2-8.6) at 2 to 5 years after diagnosis, and 8.3 (IQR, 1.2-12.1) at 5 to 10 years after diagnosis. Index scores increased significantly at each stage compared with initial or previous values (P < .0001). After 73 months (IQR, 51-96 mo) of follow-up evaluation, 138 patients had a Lémann Index score greater than 2.0. The only early factor that predicted later damage was the first index value. Intestinal resection, time, and the percentage of time elapsed with a clinically active disease were associated with progressing damage.

Conclusions: Based on an analysis of patients with Crohn's disease using the Lémann Index, nearly two thirds had substantial mucosal damage 2 to 10 years after diagnosis. High Lémann index scores at the first evaluation, time, persistent clinical activity, and intestinal resection are associated with damage.