Lysozyme overexpression in fundic gland polyps.

UNLABELLED Backgroud: Helicobacter pylori (Hp) rarely proliferates in patients with fundic gland polyps (FGPs). We recently found that FGPs express lysozyme, one of the natural defence substances against infection. We aimed to assess the degree of lysozyme expression in a cohort of consecutive FGPs. MATERIALS AND METHODS A total of 153 gastric biopsies were investigated: 93 with FGPs, 30 with normal mucosa (Nm), 15 with Hp-induced chronic gastritis (Hp-gastritis) and 15 with chronic gastritis without Hp infection (non-Hp-gastritis). Sections were stained with anti-lysozyme (muramidase). RESULTS Lysozyme was slightly to moderately expressed in the surface and foveolar pits, being markedly expressed in the neck glands in Nm, in non-Hp and Hp-gastritis. The ratio of lysozyme neck glands-foveoli was higher in non-Hp than in Nm and even higher in Hp-gastritis. In FGPs, lysozyme was markedly expressed in the surface, the foveolar pits and the cells that partly or entirely covered the microcysts. DISCUSSION AND CONCLUSION While the moderate expansion of the lysozyme-producing cells of the neck glands in Hp-gastritis might be insufficient to eradicate these bacteria, the overproduction of lysozyme in the epithelium covering FGP could be an explanation for the lack of Hp proliferation in these patients.