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

Background & Aims: Multiple tests ave available for determining Helico bacter pylori infection. Our aim was to compare the sensitivity, speci ficity, and negative and positive predictive value of the most widely available tests for diagnosis of H. pylori. Methods: A total of 268 pa tients (mean age, 53.7 +/- 15.8 years; 142 male and 126 female; 125 wh ite 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 es tablished by a concordance of test results. Results: Warthin-Starry st aining had the best sensitivity and specificity, although CLO test, UB T, 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 clinica l characteristics showed that UBT and chronic inflammation were the be st predictors of H. pylori status in patients older than 60 years of a ge. IgA was a better predictor in white patients. Conclusions: The non invasive UBT and IgG serology test are as accurate in predicting H. py lori status in untreated patients as the invasive tests of CLO and War thin-Starry.