Autoantibody Positivity in Children with Chronic Diarrhea

INTRODUCTION: We aimed to determine the frequency of autoantibody (ANA, pANCA, ASCA, PAb, GAb) positivities in children with the complaint of chronic diarrhea and inflammatory bowel disease (IBD). We also purposed explore the role of these autoantibodies in the differential diagnosis of IBD.
METHODS: In our study, serum samples of 51 patients with the complaint of chronic diarrhea and 35 healthy controls were analyzed. Clinical and laboratory data at the time of serum sampling were collected and differential diagnosis was made as the results of performed tests were recorded. For all patients, ANA, pANCA, ASCA, GAb, PAb positivities were evaluated by indirect immunofluorescence. Chronic diarrhea group was divided into two groups as IBD and non-IBD group.
RESULTS: In chronic diarrhea group, 11 (21.6%) patients had ANA, 3 (5.9%) had pANCA, 1 (2%) had PAb, 1 (2%) had GAb, 1 (2%) had ASCA positivity. From the 35 cases of the control group, 8 (22.9%) had ANA, 7 (20%) had ASCA positivity. In the control group, ASCA was found to be high (p=0.007). Six cases were diagnosed as IBD; 1 (16.7%) had ANA, 1 (16.7%) had pANCA, 1 (2%) had GAb, 1 (2%) had ASCA positivity. ASCA and GAb positivities were significantly more frequent in the IBD group (p=0.006, p=0.006, respectively).
DISCUSSION AND CONCLUSION: ASCA was determined to be significantly higher in the control group. High positivity in the control group showed that the percentage of nonspecific positivity may be high for this test. Anti-saccharomyces cerevisiae antibody ASCA and GAb of patients with diagnosis of IBD were found significantly higher. The serologic tests which are depending on pANCA, ASCA, PAb, GAb can be supportive of diagnosis and differential diagnosis of IBD. Autoantibodies in IBD may be used as a supportive diagnostic tool in selected cases, rather than in the diagnosis of IBD as a routine practice.