Efficacy of Noninvasive tests in the diagnosis of Helicobacter pylori infection in pediatric patients

Background: Helicobacter pylori infection is likely acquired in childhood. Helicobacter pylori is recognized as a cause of gastritis and peptic ulcer. Objective: To investigate some noninvasive tests, particularly H pylori fecal antigen, for the diagnosis of H pylori infection in comparison with the gold-standard invasive test, esophagogastroduodenoscopy with biopsy. Methods: We studied 250 patients (102 male; age range, 3-18 years) who underwent esophagogastroduodenoscopy with biopsy (histologic examination and rapid urease test) for a suspicious upper gastrointestinal disease; in all of them, fecal H pylori antigen, serum H pylori immunoglobulin G, and cytotoxin-associated gene product A immunoglobulin G were measured. Sensitivity and specificity of noninvasive tests were compared with those of the gold-standard esophagogastroduodenoscopy with biopsy. Results: Ninety-three patients (37%) had positive histopathologic (Giemsa staining) and rapid urease test results. The H pylori fecal antigen revealed a sensitivity of 97%, a specificity of 98%, a positive predictive value of 97%, and a negative predictive value of 98%; serum Hpylori immunoglobulin G had a sensitivity of 86%, a specificity of 80%, a positive predictive value of 72%, and a negative predictive value of 90%; and serum cytotoxinassociated gene product A inummoglobulin G had a sensitivity of 83%, a specificity of 80%, a positive predictive value of 71%, and a negative predictive value of 89%. Conclusions: Our study demonstrates that among noninvasive and easily applicable tests, particularly in small children, H pylori fecal test is simple, suitable, and has high accuracy for the screening of H pylori-positive patients.