The interrelationship between cytotoxin-associated gene A, vacuolating cytotoxin, and Helicobacter pylori-related diseases

The interrelationship between cytotoxin-associated gene A (CagA), vacuolating cytotoxin (VacA), and Helicobacter pylori-related diseases was investigated in 155 H, pylori-infected patients. Four (7%) of 60 subjects had mixed cagA(+) and cagA(-) H. pylori infections. The H. pylori isolates from 98.3% of 121 patients with anti-CagA antibodies were cagA(+), The occurrence of cagA(+) H. pylori among 76 patients with peptic ulcer disease (PUD) was higher (93.4%) than among 79 patients with functional dyspepsia (FD; 64.6%) (odds ratio [OR] = 7.80; P <.001). VacA(+) isolates were isolated from 56.6% of the PUD patients and 35.4% of the FD patients (OR = 2.37; P = .0132), For type I (cagA(+)VacA(+)) isolates, these numbers were 56.6% and 31.6%, respectively (P = .003). Only 4% of the 71 VacA(+) isolates were cagA(-). In addition, 37% of the patients with PUD were infected with cagA(+)VacA(-) H. pylori. chi(2) results did not improve when VacA was entered into the model in the presence of cagA, indicating that only cagA is associated with PUD.