[Diagnosis of Helicobacter pylori infection on gastric biopsies: Standard stain, special stain or immunohistochemistry?].

Introduction: There is no consensus on the benefit of performing a systematic complementary technique for the diagnosis of Helicobacter pylori infection. In our laboratory, a cresyl violet was carried out systematically until July 2014; since that date, a cresyl violet or immunohistochemistry is only made on request. We evaluated the value of cresyl violet staining of gastric biopsies to diagnose H. pylori infection by comparing a period of systematic staining to a time when it was made on demand.

Material And Methods: We retrospectively studied the gastric biopsy of 786 consecutive patients from April to November 2014, taken in the absence of focal endoscopic lesion. During the first period, hematoxylin-eosin and cresyl violet were performed on all biopsies. During the second period, hematoxylin-eosin was performed and then, if necessary, cresyl violet or immunohistochemistry. All hematoxylin-eosin stained slides were revised to identify H. pylori. We performed immunohistochemistry in cases of active chronic gastritis without H. pylori identified on hematoxylin-eosin or cresyl violet.

Results: We have shown that gastric biopsy performed in the absence of focal mucosal lesion are normal in 55% of cases. The percentage of H. pylori infection was similar in both groups. In cases of active chronic gastritis, H. pylori infection is visible, in most cases, on hematoxylin-eosin (94%). Immunohistochemistry should be prescribed only in case of chronic active gastritis without H. pylori identified on standard staining, with bacteria rare or atypically located.

Conclusion: In our experiment, H. pylori is present only in case of active gastritis (33% of the biopsies in our series) and being almost always identifiable on the standard staining with H-E (in 94% of the cases), it is not It is not necessary to systematically perform, on all gastric biopsies, a complementary histo- or immunohistochemical technique.