Lab Screening in Children with Suspected Inflammatory Bowel Disease

When clinical suspicion is high, normal screening lab values have limited value.
Primary care clinicians often perform screening laboratory tests when they suspect that a child might have inflammatory bowel disease (IBD). Investigators evaluated the screening utility of hemoglobin values, platelet counts, erythrocyte sedimentation rate (ESR), and albumin levels using prospectively collected data from a multisite registry of 526 children (mean age, 11.6 years) who were newly diagnosed with IBD (392 with Crohn disease; 134 with ulcerative colitis).
All four tests were normal in 30% of children with mild disease (21% of patients with Crohn disease and 54% of those with ulcerative colitis), compared with only 4% of children with moderate or severe IBD. Of the four tests, ESR was the least likely to be normal (defined as <20 mm/hour), regardless of disease severity. For example, among children with moderate or severe IBD, 18% had normal ESRs, 24% had normal hemoglobin levels, 43% had normal platelet counts, and 50% had normal albumin levels. Hematochezia was the most common presenting feature in children with mild IBD.
Comment: These results indicate that the four IBD screening tests assessed have limited value. I wish the authors had performed more sophisticated analyses, such as calculating sensitivity for different combinations of laboratory values, because early identification of children with IBD is important. The authors note that new laboratory markers, such as antibodies against neutrophils or microbial antigens, and antiglycan antibodies, might hold greater promise.
— Howard Bauchner, MD
Published in Journal Watch Pediatrics and Adolescent Medicine June 13, 2007
Citation(s):
Mack DR et al. Laboratory values for children with newly diagnosed inflammatory bowel disease. Pediatrics 2007 Jun; 119:1113-9.