ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES IN CHILDREN WITH INFLAMMATORY BOWEL-DISEASE - PREVALENCE AND DIAGNOSTIC-VALUE

Background: Antineutrophil cytoplasmic antibodies (ANCA), particularly perinuclear ANCA (p-ANCA), have been found more frequently in sera fr om patients with ulcerative colitis (UC) than in sera from Crohn's dis ease (CD) or unclassified enterocolitis (UC) patients. This 2-center s tudy examined sera from 102 pediatric patients with inflammatory bowel disease (IBD) to evaluate their diagnostic value and assess their rel ationship with disease features, distribution, activity and treatment. Methods: The serum ANCA of 102 children with IBD were measured: 33 UC , 64 CD and 5 UE with various disease locations and degrees of activit y. The mean age at the onset of symptoms was 10.7 years (1 to 16.3 yea rs). Sera from 26 unaffected first degree relatives and 20 children wi thout IBD were also investigated. ANCA were detected using indirect im munofluorescence of ethanol-fixed granulocytes. Results: There were AN CA in the sera of 24/33 children with uc (73%), 9/64 with CD (14%) and 4/5 with UE (80%). p-ANCA were more frequent than cytoplasmic-ANCA in positive sera: UC = 67%, CD = 57% and UE = 75%. The presence of ANCA was 73% sensitive and 81% specific for a diagnosis of UC, compared to other IBD (p < 0.001). Three children with proved sclerosing cholangit is associated with UC were all positive. There was no link between ANC A-positive sera and disease activity, or other endoscopic or clinical criteria. ANCA were detected in 4/26 first degree relatives (15%) and in 1/20 control subjects (5%). Conclusions: Because of their sensitivi ty and specificity, ANCA may be helpful in the clinical assessment of patients with IBD, and especially those with UC. However, there is no link between the pressure of p-ANCA and the site of UC or its activity , so that it cannot be used to monitor medical treatment or surgical i ndications.