Pattern of helicobacter pylori associated gastric lesions at Muhimbili National Hospital using immunohistochemistry

Abstract

ABSTRACT Background: H. pylori is a bacterium which affects the majority of population worldwide, and accounts for more than 50% of the population. The H. pylori infection is common in developing countries like Tanzania where more than 50% of the population are infected. H. pylori infection is a communicable disease which is transmitted through the faecal-oral route in contaminated water and food. It is associated with acute, chronic and atrophic gastritis, peptic ulcers and malignancies such as adenocarcinoma and mucosal associated lymphoid tissue lymphoma. The cost of management of patients to the country is high and may result into a vicious cycle of poverty. Immunohistochemistry is one of the superior methods and is regarded as a gold standard for detection of H. pylori, hence it will help in the establishment of the relationship between the bacteria and the associated lesions as it has been reported in this study. Despite its worldwide distribution, few studies have been done in Tanzania to detect the H. pylori in gastric biopsies in relation to the gastric pathologies it causes. Objective: To determine the pattern of H. pylori associated gastric lesions at MNH using immunohistochemistry. Methodology: A descriptive cross-sectional study, retrospective laboratory based study was conducted at Muhimbili National Hospital Histopathology Laboratory in which 50320 specimens were retrieved and 743 were gastric specimens. 170 FFPE blocks and slides were retrieved from the archive of the year 2012- 2016, and were then stained with Hematoxylin and Eosin. All cases were immunohistochemically stained using a polyclonal antibody (DAKO) to detect H.pylori antigens and reviewed by two senior surgical pathologists (supervisors). The protocols for the procedures were adopted from MNH SOPs. Results: 170 gastric biopsies were identified (patient mean age 50, 109 males, 61 females). Morphologies included 61% (103/170) inflammatory lesions, 4% (7/170) benign neoplastic lesions and 35% (65/170) malignant lesions. H. pylori was detected in 11.2% of cases (19/170) by H&E and 37% (63/170) by immunohistochemistry, and was most frequently seen in cases with chronic inflammation 55.6% (35). vii Conclusion: H. pylori is a common bacterial infection most frequently associated with chronic inflammation and was identified at a prevalence lower than described in the literature. Immunohistochemistry was more sensitive than H&E alone in identifying H. pylori. Additional studies are needed to determine the prevalence in the general population.