[Efficacy of four widely used techniques of the diagnosis of Helicobacter pylori infection in gastric ulcer disease].

OBJECTIVE

To study the accuracy of four currently used tests for the diagnostic of Helicobacter pylori infection among gastric ulcer patients with a gold standard as reference which combines several diagnostic methods.

MATERIAL AND METHODS

Seventy-three consecutive gastric ulcer patients were prospectively studied. From all patients, three biopsies each were obtained from both antrum and body (two for haematoxylin-eosin staining and one for rapid urease test--Jatrox H.p. Test--. Also, IgG ELISA serology (Helico G) and 13C-urea breath test were performed. According to the gold standard, a patient was considered to be infected with H. pylori when at least two tests were positive; a patient was considered not to be infected with H. pylori when at least three tests were negative.

RESULTS

Among gastric ulcer patients, the prevalence of H. pylori infection was 87.6% (95% CI: 78%-93%) with the gold standard as reference. The sensitivity and specificity values were as follows: histology (antrum), 96.8% (89%-99%) and 100% (66%-100%), respectively; histology (body), 98.4% (91%-100%) and 100% (66%-100%); urease test (antrum), 71.8% (60%-81%) and 100% (66%-100%); urease test (body), 96.8% (89%-99%) and 100% (66%-100%); breath test, 100% (94%-100%) and 100% (66%-100%), and serology, 95.3% (87%-98%) and 100% (66%-100%). The sensitivity of the urease test was higher with a body biopsy specimen (McNemar: 15; p < 0.001).

CONCLUSIONS

All diagnostic tests (histology, rapid urease test, 13C-urea breath test and serology) are highly accurate for the diagnosis of H. pylori infection among gastric ulcer patients with the exception of the rapid urease test performed with antrum biopsy specimens, where this test displays a lower sensitivity for bacterial detection.