Background: Some patients with Crohn's disease (CD) in clinical remission experience disease progression despite feeling well. We need simple ways to recognize those patients and treat them accordingly and in a timely manner. Anaemia is believed to have prognostic significance as highlighted by previous research.
Methods: We observed changes in treatment upto 12 months after the initial evaluation in a cohort of patients with CD in clinical remission with Harvey Bradshaw Index (HBI) <4. Baseline measurements of C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR) and hemoglobin were available for all patients. Treatment change was defined as surgery, new therapy added, switch or escalation of existent biologic therapy. World Health Organization criteria were used for the definition of anaemia.
Results: A total of 90 CD patients (median age 39 years; 50% female) were included with a mean HBI of 2.33; 95% confidence interval (CI) 1.76–2.9. Anaemia was observed in 25% of patients. During the one year follow up 36% required a change in management (surgery or different medical treatment). In multivariate logistic regression analysis anaemia was the only factor factor significantly associated with a treatment change: Odds Ratio (OR)=4; 95% CI 1.3–12; p=0.015. Age, gender, disease duration, treatment with immunomodulators, treatment with biologics, ESR and surprisingly CRP (OR=1.4; 95% CI 0.46–4.42; p=0.537) were not associated with treatment change. Nevertheless CRP showed statistically significant linear correlation with anemia in CD (r=−0.035). When the same analysis was conducted in a cohort of 42 ulcerative colitis patients in clinical remission (mean partial Mayo Score 1.56; 95% CI 0.83–2.29) only ESR (OR=2.5; 95% CI 1.15–5.45; p=0.21) was significantly associated with treatment change. Anaemia in CD has probably stronger prognostic value than inflammatory markers, because it reflects not only inflammation but actual bowel damage.
Conclusions: Anemia was a stronger predictor of treatment change compared to CRP in this cohort of Crohn's disease patients in clinical remission followed up for one year. Silent Crohn's disease with anemia is associated with disease complications or subclinical inflammation and should be therefore investigated and managed appropriately. Further studies of the true significance of anaemia in quiescent Inflammatory Bowel Disease are needed.