ACCURACY OF INVASIVE AND NONINVASIVE TESTS TO DIAGNOSE HELICOBACTER-PYLORI INFECTION

Background & Aims: Multiple tests ave available for determining Helicobacter pylori infection. Our aim was to compare the sensitivity, specificity, and negative and positive predictive value of the most widely available tests for diagnosis of H. pylori. Methods: A total of 268 patients (mean age, 53.7 +/- 15.8 years; 142 male and 126 female; 125 white and 143 nonwhite) was tested for H. pylori infection by [C-13]urea breath test (UBT), measurement of serum immunoglobulin (Ig) G and IgA antibody levels, and antral biopsy specimens for CLO test, histology, and Warthin-Starry stain. No patient received specific treatment for H. pylori before testing. The infection status for each patient was established by a concordance of test results. Results: Warthin-Starry staining had the best sensitivity and specificity, although CLO test, UBT, and IgG levels were not statistically different in determining the correct diagnosis. The absence of chronic antral inflammation was the best method to exclude infection. Stratification of results by clinical characteristics showed that UBT and chronic inflammation were the best predictors of H. pylori status in patients older than 60 years of age. IgA was a better predictor in white patients. Conclusions: The noninvasive UBT and IgG serology test are as accurate in predicting H. pylori status in untreated patients as the invasive tests of CLO and Warthin-Starry.