P181 Accuracy of non-invasive tests in the initial diagnostic work-up of paediatric inflammatory bowel diseases
F. Civitelli*, M. Aloi, A. Dilillo, S. Oliva, L. Stronati, F. Viola, S. Cucchiara
Sapienza University, Paediatric Gastroenterology and Liver Unit, Rome, Italy
Upper and lower endoscopy with histology, together with imaging of the small bowel, is the gold standard for the diagnosis of inflammatory bowel disease (IBD) in children. Because of high costs and invasive nature of these techniques, accurate selection of patients is mandatory. We aimed to assess the accuracy of non-invasive tests including faecal calprotectin (FC), blood inflammatory markers (BIM), and bowel ultrasound (US) alone or in combination as first level investigations in children with suspected IBD.
Consecutive patients referred to our unit for a clinical history compatible with IBD were enrolled during a 3-year period. All underwent FC (Calprest®, Eurospital), C-reactive protein [CRP], erythrocyte sedimentation rate (ESR) and bowel US as first investigations. Endoscopy with biopsies was the gold standard for diagnosis. At US pathological findings were BWT>3 mm, BW vascularity, loss of stratification, and enlarged mesenteric nodes. Multiple logistic analysis with stepwise method considering IBD diagnosis as dependent variable was conducted. Sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV) of laboratory, and US parameters alone or in combination were analysed according to the final diagnosis, and
100 patients (58 males, median age 12) were enrolled. The final diagnosis was IBD in 69 (57 CD and 12 CU) other than IBD in 31. Mean values of CRP, ESR, FC, and BWT were higher in IBD vs non-IBD patients (p < 0.001) (Table 1). Multiple logistic analysis showed that independent variables predictive of IBD were FC (OR 44.8; p < 0.01), BWT (OR 20.4, p < 0.001) and ESR (OR 9; p < 0.05). The combination of 3 or 2 parameters was more frequent in IBD patients (p < 0.01). Table 2 shows SE, SP, PPV, and NPV of these parameters alone or in combination.
|CRP (mg/dl)||17.7 ± 19||3.5 ± 6 0.001||0.001|
|ESR (mm/h)||40 ± 22||17 ± 11||0.001|
|CALPROTECTIN (ug/g)||292 ± 287||19.2 ± 10||0.001|
|BWT (mm)||6 ± 2.3||2 ± 0.6||0.001|
|SE (%)||SP (%)||PPV (%)||NPV (%)|
|2 (at least 2 of 3)||96||94||97||92|
|2 (FC + BWT)||91||100||100||86|
|3 (FC + BWT + ESR)||71||100||100||64|
The combination of FC, BIM, and bowel US may help to select children needing further invasive procedures and allow avoiding or delaying endoscopy in patients with negative initial diagnostic work-up.