COMPARISON OF BIOPSY SITES FOR THE HISTOPATHOLOGIC DIAGNOSIS OF HELICOBACTER-PYLORI - A TOPOGRAPHIC STUDY OF HELICOBACTER-PYLORI DENSITY AND DISTRIBUTION

The histologic demonstration of characteristic curved, spiral bacilli an the gastric mucosa is considered the gold standard for the diagnosis of Helicobacter pylori infection. However, in some cases the urea breath test or serologic tests may be positive, yet gastric biopsy specimens fail to reveal H. pylori. The objectives of this study were (1) to analyze the density and distribution of H. pylori in different regions of the stomach, (2) to ascertain which area of the stomach is a preferential site for obtaining biopsy specimens, and (3) to determine whether the presence of neutrophils or lymphoid aggregates correlates with the presence of detectable organisms in the same biopsy specimen. Eighty-nine patients with H. pylori infection underwent gastric mapping. The density of H. pylori, neutrophils, and lymphoid follicles was assessed semi-quantitatively in each biopsy site. The likelihood of getting a false-negative result was also calculated for each biopsy site. All biopsy specimens from the antral lesser curvature, at or near the incisura, had detectable H. pylori. Scores for this area and the cardia were higher than scores for the gastric corpus, but most differences were not significant. Fewer than 3% of antral biopsy specimens were false-negative, compared to between 6% and 9% of those from the corpus (p = 0.02). Neutrophils were present in more than 94% of all antral biopsy specimens, compared to 60% to 86% of specimens from the corpus (p < 0.01). Lymphoid follicles were detected in approximately two-thirds of antral biopsy specimens but in fewer than half of those from the corpus. Based on data from this study, we conclude that two antral biopsy specimens (one from the lesser and one from the greater curvature) yield virtually 100% sensitivity for detecting H. pylori infection. Specimens from the corpus should be obtained far evaluation of the distribution and severity of gastritis, but they do not increase the diagnostic yield unless extensive intestinal metaplasia is present in the antrum. The presence of neutrophils and lymphoid follicles has a high positive predictive value, but their absence, particularly in the corpus, does not exclude H. pylori infection.