Chronic Helicobacter pylori infection in a population in southern Sweden analysed by histopathology, immunoblot and ELISA serology.

Background. Many individuals are infected with the bacterium Helicobacter pylori. Some develop ulcers or mucosal atrophy. Aims. To correlate the histological characteristics of the H. pylori-induced gastritis to the immunoblot pattern of the H. pylori infection and to compare the presence of H. pylori bacteria in tissue specimens with ELISA serology and immunoblot analysis. Methods. One hundred and sixty-six consecutive patients were referred to gastroscopy. Forty patients were excluded for various reasons and 126 were included in the study. Results. Twenty-three patients had ulcerations and 25 erosions. Ninety-two (73%) had a chronic gastritis and in 90 (71%) it involved both the antrum and corpus. Ninety-one (72%), of whom 96% had a chronic gastritis, had visible bacteria in the tissue specimens, used as the 'gold standard' for the detection of infection. In patients with chronic gastritis 65 (70%) had positive H. pylori ELISA serology, 27 (30%) had negative H. pylori ELISA, while 76 (83%) had a positive immunoblot pattern. The ELISA positive patients had more advanced chronic gastritis but a lower frequency of metaplasia and atrophy. Acute inflammatory activity in the chronic gastritis had a high immunoreactivity to 120 kDa (CagA) protein and was significantly correlated to antibody reactivity to proteins in the 53-65 kDa range (heat shock proteins) and to a 43 kDa subunit. Metaplasia and atrophy in antrum was associated with a 62 kDa protein band. Conclusion. Almost all H. pylori-infected patients had a pangastritis, visible in both antrum and corpus. Acute inflammatory activity in the chronic gastritis and the presence of metaplasia and atrophy in antrum were associated with a specific immunoblot pattern, indicating infection with more virulent strains. Immunoblot analysis had a better sensitivity than ELISA H. pylori serology.