The effect of Helicobacter pylori on neutrophil chemotaxis is independent of cagA.

Sixteen Helicobacter pylori strains were studied in order to determine their neutrophil chemotactic activity and the association with the presence cagA gene. Neutrophil chemotactic activity was detected by a modified Boyden chamber method and the results were expressed in terms of chemotactic index (CI). The presence of cagA was determined by PCR. Of the 16 strains, eight were cagA+ and eight were cagA-. All of the isolated strains showed chemotactic activity. The mean value of CI of the patient group was significantly higher than the negative control (P < 0.01). The mean value of CI of zymosan-activated serum (P < 0.05) and the reference strain H. pylori NCTC 11637 (HP11637) (P < 0.01) was significantly higher than the patient group's mean value of CI. There were no statistical significance in the CI between cagA+ and cagA- strains (P > 0.05). It is concluded that H. pylori attracts neutrophils by chemotaxis, however, there is no association with cagA.