Comparison of two invasive diagnostic tests for Helicobacter pylori after antimicrobial therapy

Objective. To compare the accuracy of two invasive tests, the rapid urease test and histology, one month after antimicrobial treatment of Helicobacter pylori. Material and methods. In the present study the rapid urease test was compared with histology in a group of 232 patients who fulfilled the Maastricht criteria for eradication of H. pylori infection. All patients had one week of triple therapy which included omeprazole b.i.d. and two of three antibiotics ( metronidazole, chlarythromycin and amoxicillin) b.i.d. One month after antimicrobial therapy, all the patients underwent upper gastrointestinal endoscopy. Two biopsy samples were taken from the antrum and corpus for each test. We used the office rapid urease test, which was previously evaluated, and histology with Giemsa stain. Results. Concordance between both methods was 94% for antrum biopsies, 97% for corpus biopsies and 96% for pooled data. Kappa values were 0.81 for antrum ( 95% CI: 0.77 - 0.85%), 0.87 for corpus ( 95% CI: 0.83 - 0.91%) and 0.84 for pooled data ( 95% CI: 0.80 - 0.88%). Specificity of the rapid urease test is very high ( over 98%), sensitivity is lower, but can be improved, if biopsy specimens are taken from both the corpus and the antrum ( to 83.6%). Conclusions. The rapid urease test with two biopsies from the antrum and corpus of the stomach is a reliable diagnostic method for evaluation of the success of H. pylori eradication one month after antimicrobial therapy.