Measurement of reticulocyte and red blood cell indices in the evaluation of anemia in inflammatory bowel disease.

Background: The commonest types of anemia in inflammatory bowel disease (IBD) are iron deficiency (IDA) and anemia of chronic disease. The differentiation between these two conditions is important for the management of the patient. The aim of this study was to investigate the usefulness of reticulocyte and red blood cell indices in the evaluation of anemia in IBD.

Methods: One hundred IBD patients [49 ulcerative colitis (UC), 51 Crohn's disease (CD)] and 102 healthy controls were enrolled. Measurement of reticulocyte and red blood cell indices was performed using the Coulter LH780 Hematology Analyzer (Beckman Coulter). Additionally, serum levels of ferritin, transferrin saturation (Tsat) and soluble transferrin receptor (sTfR) were analyzed in all patients and controls.

Results: The prevalence of anemia was 41.2% for UC and 42.9% for CD, whereas 30 IBD patients (30%) had IDA. Red cell Distribution Width (RDW), Red blood cell Size Factor (RSF), and Reticulocyte Distribution Width-Coefficient of Variation (RDWR-CV) were found significantly correlated with both Tsat and sTfR but not with ferritin levels. Patients with IDA had significantly higher RDW and RDWR-CV and significantly lower RSF levels compared with those without IDA. High values of RDW (sensitivity 93%, specificity 81%) and low values of RSF (sensitivity 83%, specificity 82%) were the best markers for the diagnosis of IDA. Both RDWR-CV and RDWR-SD were significantly correlated with disease activity and CRP levels.

Conclusion: RDW, RSF and RDWR, could be useful markers for the evaluation of anemia and disease activity in IBD.