EXPRESSION OF CD44 AND ITS VARIANTS ON GASTRIC EPITHELIAL-CELLS OF PATIENTS WITH HELICOBACTER-PYLORI COLONIZATION

Background-Studies have suggested that expression of the adhesion mole cule CD44 may be of prognostic importance in gastric cancer. In additi on, there is strong evidence that Helicobacter pylori has a role in ga stric cancer. Aims-To determine the expression of CD44 and its variant s (v6, v9) and HLA class II molecules on human gastric epithelial cell s and intraepithehal lymphocytes in patients with and without H pylori infection. Patients-Eighteen patients (seven men and 11 women) attend ing for endoscopic evaluation because of upper gastrointestinal sympto ms were included. An additional 10 patients (five men and five women) were analysed for CD44 variant expression). Methods-Biopsy specimens w ere taken from the gastric antrum during endoscopy. Gastric epithelial cells and intraepithelial lymphocytes were examined by two colour flo w cytometry and compared in patients with and without H pylori infecti on. Results-Expression of CD44 and its variants (CD44 v9) was increase d in epithelial cells but not in intraepithelial lymphocytes. Both epi thelial cells and intraepithelial lymphocytes expressed higher levels of HLA class II molecules (DR and DP), possibly as a result of local c ytokine production. Furthermore, results showed upregulation of CD44 o n a gastric epithelial cell line (AGS) by cytokines and peripheral blo od mononuclear cell supernatant. Conclusions-These data suggest that H pylori, either directly or through a local inflammatory response, is responsible for increased expression of CD44 and its variant CD44 v9. These data are of potential importance in relation to increased expres sion of CD44 and CD44 v9 on gastric carcinoma.