Comparison of Helicobacter pylori gastric density by culture, histology and 13C urea breath test.

Objectives. -In Helicobacter pylori infection, the bacterial burden may play a role in the pathogenesis of gastric or duodenal ulcerated lesions. It could also influence the results of antimicrobial therapy No simple test has been validated to quantify Helicobacter pylori density. The aim of this study was to determine the value of histology and/or C-13-urea breath test to quantify the infection as compared with quantitative culture, taken as a reference method. Patients and methods. -Biopsies samples were taken from the antrum at endoscopy in 72 patients. Thirty-seven patients with positive urease test at 20 minutes were enrolled in the study Bacterial density was evaluated from biopsies by quantitative culture and semi-quantitative histological examination (score from 0 to 3). The bacterial density was evaluated as well by C-13-area breath test from the proportion of (CO2)-C-13 in exhaled air (Delta(13)CO(2)) at 20, 40, and 60 minutes as compared with the basal level. Results. -The bacterial density, evaluated by quantitative culture ranged from 5 CFU to 110,000 CFU per mg of tissue. By histology, a score 1 was found in 5 patients, a score 2 in 17 and a score 3 in 15. Delta of (CO2)-C-13 measured by C-13-urea breath test ranged fr om 0.2 to 117.5, from 0.2 to 102, and from 0.6 to 66.7 at 20, 40 and 60 minutes respectively. The quantity of bacteria measured by culture was not significantly higher for these with a score of 3 as compared with those with a pooled score of 1 and 2 (P < 0.05). No significant correlation was found between the results of quantitative culture and these of breath test Conclusion. -In practice, evaluation of bacterial burden by a histological score seems only accurate for the most severe density (score 3). The C-13-urea breath test does not allow a reliable quantitative evaluation.