Co-expression in Helicobacter pylori of cagA and non-opsonic neutrophil activation enhances the association with peptic ulcer disease

Aims-To investigate the association of cagA positivity and non-opsonic neut rophil activation capacity in wild-type Helicobacter pylori strains with pe ptic ulcer disease or chronic gastritis only. Methods-Helicobacter pylori were isolated from antral biopsies of 53 consec utive patients with chronic antral gastritis, of whom 24 had peptic ulcer d isease endoscopically. The presence of cagA, a marker for the cag pathogeni city island, was determined by polymerase chain reaction with specific olig onucleotide primers, and non-opsonic neutrophil activation capacity by lumi nol enhanced chemiluminescence. Results-The cagA gene was present in 39 of 53 (73.6%) strains, 20 of which (83.3%) were from the 24 patients with peptic ulcer disease and 19 (65.5%) from the 29 patients with chronic gastritis only. Nonopsonic neutrophil act ivation was found in 29 (54.7%) strains, 16 of which (66.7%) were from pati ents with peptic ulcer disease, and 13 (44.8%) from those with chronic gast ritis. Non-opsonic neutrophil activation was found more frequently in cagA( +) than cagA(-) strains (59% v 42.9%). Whereas four of the 14 cagA(-) strai ns and eight of the 24 non-opsonic neutrophil activation negative strains w ere from patients with peptic ulcer disease, only two of 24 (8.3%) peptic u lcer disease strains expressed neither cagA nor nonopsonic neutrophil activ ation. The cagA gene and non-opsonic neutrophil activation capacity were co -expressed in 14 of 24 (58.3%) strains from patients with peptic ulcer dise ase, and in nine of 29 (31%) strains from individuals with chronic gastriti s. Conclusions-Positivity for cagA and non-opsonic neutrophil activation occur independently in wild-type H pylori strains. However, co-expression of the two markers enhanced the prediction of peptic ulcer disease.