Use of serologic markers as a screening tool in inflammatory bowel disease compared with elevated erythrocyte sedimentation rate and anemia.

OBJECTIVES: The purpose of this work was to evaluate the use of serologic testing as a screening test for inflammatory bowel disease compared with erythrocyte sedimentation rate and hemoglobin in a referred patient population with suspected inflammatory bowel disease. PATIENTS AND METHODS: A retrospective study was performed, reviewing medical charts of patients who had inflammatory bowel disease serology performed at Prometheus Laboratories from September 2002 to September 2004. Patients were divided into 4 categories: ulcerative colitis, Crohn disease, indeterminate colitis, and noninflammatory bowel disease groups. Patients were categorized based on clinical evaluation by board-certified pediatric gastroenterologists.
RESULTS: A total of 227 patients seen at the Lucile Packard Children's Hospital Gastroenterology Clinic had inflammatory bowel disease serology performed at or before the time of diagnosis. Seventeen charts were excluded secondary to inadequate information. Forty children were found to have inflammatory bowel disease, a prevalence of 19%. Overall, serologic testing for inflammatory bowel disease had 60% sensitivity and 92% specificity. A positive laboratory test for anemia or an elevated erythrocyte sedimentation rate had 83% sensitivity, whereas the combination of anemia and elevated erythrocyte sedimentation rate had 96% specificity. The positive predictive value of serologic testing was 60% compared with 79% in patients with anemia and elevated erythrocyte sedimentation rate. The positive predictive value of serologic testing in the subgroup of subjects without rectal bleeding (139 subjects) was only 35% compared with 60% using routine tests. Almost one third of all positive serologic tests were in patients with no demonstrable inflammatory bowel disease.
CONCLUSIONS: As a pediatric inflammatory bowel disease screening strategy for the general pediatrician or gastroenterologist, the measurement of the combination of erythrocyte sedimentation rate and hemoglobin has a higher positive predictive value and is more sensitive, more specific, and less costly than commercial serologic testing.