Colonisation density and topographic localisation of Helicobacter pylori do not depend on the cagA status

Aims - To explore the correlation between the cagA status of Helicobacter pylori and the density and topographic localisation of H pylori. Methods - Gastric antral biopsy specimens were taken from 716 consecutive patients, including 293 H pylori positive patients (124 men, 169 women; mean age, 52.6 years; range, 12-87). A serum sample was taken for determination of IgG anti-CagA antibodies (sensitivity of 94.4% and specificity of 92.5%). The density of H pylori was assessed semiquantitatively (grades I-IV) in biopsy specimens stained with the modified Giemsa stain. Topographic localisation was classified as follows: score A, H pylori closely attached to the mucosa; score B, H pylori attached to the mucosa and in the mucus; and score C, H pylori solely in the mucus. Results - CagA antibodies were present in 154 (52.5%) of the patients. There was no significant difference in colonisation density and cagA status: grade I, 23 (14%); grade II, 78 (50.6%); grade III, 42 (27.5%); and grade IV, 11 (7.2%) in the cagA⁺ strains and 29 (21.2%), 57 (40.8%), 38 (27%), and 15 (11%), respectively, in the cagA^- strains. There was no difference in topographic localisation between cagA⁺ and cagA^- H pylori. Mean anti-CagA titres were 0.84, 0.84, 0.89, and 0.73 in patients with grades I-IV bacterial density, respectively. Conclusion - Antibody titres do not correlate with H pylori density and there is no difference in density between cagA⁺ and cagA^-H pylori strains. In addition there is no difference in topographic localisation between cagA⁺ and cagA^- H pylori strains.