Laboratory values for children with newly diagnosed inflammatory bowel disease.

Objective: The goal was to determine how often common laboratory tests yield normal results at the time of diagnosis for children with inflammatory bowel disease.
Methods: Data were obtained from a registry of children with newly diagnosed inflammatory bowel disease who were enrolled prospectively in 18 US/Canadian centers. Laboratory values investigated included hemoglobin level, platelet count, albumin level, and erythrocyte sedimentation rate. Disease severity was categorized by physician global assessment.
Results: A total of 526 children (mean age: 11.6 years; 58% male; 392 with Crohn disease and 134 with ulcerative colitis) were studied. All 4 values were normal for 21% of patients with mild Crohn disease and 54% with mild ulcerative colitis. In contrast, only 3.8% of children with moderate/severe Crohn disease and 4.3% with moderate/severe ulcerative colitis had normal results for all 4 tests. The erythrocyte sedimentation rate was least likely to be normal; overall, 26% of patients with inflammatory bowel disease had a normal erythrocyte sedimentation rate, including 18% with moderate/severe disease. Hemoglobin levels were normal for 32%, platelet counts for 50%, and albumin levels for 60%. There was no clear association between Crohn disease location and either severity or number of normal laboratory values. In contrast, there were direct correlations between ulcerative colitis disease severity and both the extent of bowel inflammation and the number of abnormal laboratory tests.
Conclusion: The presence of normal screening laboratory studies should not dissuade clinicians from considering a diagnosis of inflammatory bowel disease.