APOPTOSIS IN CHRONIC GASTRITIS - EVALUATION OF THE GASTRIC-MUCOSA BY DNA FLOW-CYTOMETRY AND THE EXPRESSION OF THE HIGH-MOLECULAR-WEIGHT CYTOKERATIN

Background/Aims: A series of premalignant lesions, including chronic g astritis (CG) intestinal metaplasia (IM) and dysplasia are associated with gastric carcinogenesis. The present study aimed to define these p recancerous gastric lesions further by the study of the cellular DNA u sing flow cytometry, and the expression of the high molecular weight ( 68 KD alpha) Cytokeratin ''CK1'' proposed as a marker for epithelial c ells dying by apoptosis. Material and Methods: Multiple antral biopsie s from each of 92 cases with gastric dyspepsia were subjected for DNA content analysis using flow cytometry, and immunostaining using anti-C K1 monoclonal antibody. Results: Chronic gastritis (CG) was present in . 85 (92.4%) of cases, 14/85 (16.5%) cases showed chronic superficial gastritis (CSG), and 71/85 (83.5%) cases were chronic atrophic gastrit is (GAG). Sixty two of the 85 (74.7%) cases with CG revealed variable degrees of activities. A hypodiploid ''Sub-G1'' peak was detected in 3 5 of 85 cases with CG. This peak was significantly higher in active ch ronic gastritis (ACG) than in the inactive (ICG) cases (p<0.005). Prol iferative activity of cases with CG was higher than in normal cases (p <0.05) and in cases with ACG than in ICG (p<0.05). Abnormal DNA-conten t (aneuploidy) was present in 16 (18.8%) of the 85 cases with CG. The presence of gastric epithelial cells with morphological changes typica l of apoptosis in cases showing hypodiploid ''Sub-G1'' peak high proli feration, and DNA-aneuploidy, suggests that these cells may be apoptot ic bodies. Mild degree of apoptosis was present in some cases (57%) wi th histologically normal mucosa, while dense apoptotic bodies occurred in 87% of cases with chronic gastritis. These apoptotic bodies were c onstantly expressing CK1, except those in normal mucosa, suggesting th at CK1 can be used as a marker for dying epithelial cells by apoptosis . CK1 was detected in 16 (100%) aneuploid cases which also showed apop tosis. Conclusion: The presence of apoptotic bodies in cases with chro nic gastritis especially in those showing DNA-aneuploidy, may accounts for the deletion of cells with altered DNA.