ارزش آنتي ژن هليكو باكتربيلوري در نمونه ي مدفوع كودكان در تشخيص عفونت هليكوباكترپيلوري

Diagnostic Value of Coproantigens for Helicobacter Pylori Infection in Children

Background: Helicobacter pylori as a main pathogen in human gastrointestinal tract is usually acquired in childhood. Early and accurate diagnosis of the infection in children is very important. The aim of our study was to compare the results of invasive tests (endoscopy, gastric mucosal biopsy and histology) with the noninvasive, newly developed coproantigen test to diagnose H pylori infection. Materials and Methods: In this analytical study convenience sampling was carried out on children suffering from dyspepsia who referred to endoscopic ward of Tabriz childrenʹs hospital. The subjects (130 patients) underwent upper gastrointestinal endoscopy and gastric biopsy and then were tested for coproantigens by immunoassay (HPAGT kit). Patients with grade one Helicobacter and more, in histologic specimens were considered Helocobacter-infected cases. Sensitivity, specificity, positive and negative predictive value of stool coproantigen test compared with gastric biopsy were determined and the data were analysed using Mc Nemar and chi2 -tests. Results: Ninety six dyspeptic children (65 boys and 31 girls) at the mean age of 8.3+0.3 were investigated. In histologic survey 62 patients (64.6%) were Helicobacter positive, among whom 34 positive cases of coproantigen test were also reported. Sensitivity, specificity positive and negative predictive value of Hpylori coproantiqen stool antigen test were 54.8%, 79.4%, 82.9%, 49.9% respectively. (p=0.001). Sensitivity and specificity of histologic survey (grade two and over) were higher than those of coproantigen test (p= 0.001). Conclusions: H. pylori, coproantigen test has a lower sensitivity and specificity compared to "Gold Standard" test. Potential value of this test as indicative of HPylori infection laecomes dominant in treatment and eradication period. Further studies with higher sample number are recommended.