Stratification of Crohn’s Disease Patients Using the Lemann Index to Quantify Gut Damage: A 5-Year Prospective Study: ACG Governors Award for Excellence in Clinical Research Presidential Poster

Abstract

Introduction: Crohn’s disease (CD) is a lifelong, progressive destruction of the gastrointestinal tract due to chronic inflammation. The trajectory of damage will vary from mild with a slow/indolent course to aggressive disease with progressive damage and rapid post-op recurrence. The newly created Lemann index quantifies global digestive tract damage. We utilized the Lemann index in an independent cohort of CD patients to validate this scoring metric over time and stratify patients based on 5 year trajectories of damage. Methods: This was an observational study from a consented, prospective, natural history registry from a tertiary IBD center. CD patients with 5 year follow-up formed the study population. Lemann index was calculated using a computerized scoring metric from the first and last clinical encounters. Patients were further categorized based on the delta Lemann score (improvement, no change or deterioration). Subgroups were created by dichotomizing mean improvement, mean deterioration, and no change and these quintiles were used for association analysis with patterns of healthcare utilization, treatment, and biochemical inflammation. Results: There were 377 CD patients with 5 year follow-up who formed the study population (mean age 45.6+14.4 years (S.D.); 57.8% female; mean disease duration 18.8 years; overall surgical exposure 67.9%). Over the 5 year study period 39% required surgery and 14.3% required 2 or more operations. The initial Lemann score ranged from 0-54 (mean 9.4) and the final Lemann score ranged from 0-75 (mean 12.6). The delta Lemann score ranged from -22-47 (mean 3.2). Patients were stratified into quintiles based on delta Lemann score. Age, gender, and disease duration did not associate with delta Lemann score, but patterns of healthcare utilization and treatment (i.e. annual steroid, immunomodulator, biologic, narcotic use) were significantly associated. Annual patterns of biochemical inflammation (CRP elevation) were associated with worsening delta Lemann score. Conclusion: The Lemann index was readily applied to an independent cohort of CD patients and the delta Lemann score over a 5 year time period was significantly associated with patterns of healthcare utilization, treatment, and inflammation. Delta Lemann score may function as a marker of disease trajectory for risk sub-stratification and prognostication.Table 1: Five-Year Trajectory of Crohn’s Disease Based on Delta Lemann Score