Association of peptic ulcer with increased expression of Lewis antigens but not cagA, iceA, and vacA in Helicobacter pylori isolates in an Asian population
Py. Zheng et al., Association of peptic ulcer with increased expression of Lewis antigens but not cagA, iceA, and vacA in Helicobacter pylori isolates in an Asian population, GUT, 47(1), 2000, pp. 18-22
Background-Studies in Western populations suggest that cagA, iceA, and vacA
gene status in helicobacter pylori isolates is associated with increased v
irulence and peptic ulcer disease.
Aim-To investigate the relationship between peptic ulcer and expression of
Lewis (Le) antigens as well as cagA, iceA, and vacA in H pylori isolates in
Singapore.;Methods-Expression of Le antigens in H pylori isolates obtained
from patients with dyspepsia was measured by enzyme Linked immunosorbent a
ssay. The cagA, iceA, and vacA status was determined by polymerase chain re
action.
Results-Of 108 H pylori isolates, 103 (95.4%) expressed Le(x) and/or Le(y),
while Le(a) and Le(b) were expressed in 23 (21.3%) and 47 (43.5%) isolates
, respectively. Expression of two or more Le antigens (Le(x), Le(y), Le(a),
or Le(b)) was significantly higher in H pylori isolated from ulcer patient
s than in non-ulcer patients (89.6% v 73.2%, p=0.035). There were no signif
icant differences in the prevalence of cagA or iceA1 in H pylori isolates f
rom peptic ulcer and non-ulcer patients (86.6% v 90.2% for cagA; 70.1% v 68
.3% for iceA1), and no association of peptic ulcer with any specific vacA g
enotype.
Conclusions-The present study indicates that peptic ulcer disease is associ
ated with increased expression of Lewis antigens but not cagA, iceA, or vac
A genotype in H pylori isolates in our population. This suggests that cagA,
iceA, and vacA are not universal virulence markers, and that host-pathogen
interactions are important in determining clinical outcome.