Background. Accumulation of p53 has been recognized in the gastric mucosa i
nfected with Helicobacter pylori. We investigated the prevalence of p53-pos
itive cells in the gastric mucosa before and one month after eradication of
H. pylori and the relationship between p53 positivity and inflammation and
cell proliferation.
Methods. The subjects included 24 H. pylori-posit ive patients. They achiev
ed eradication one month after anti-H. pylori therapy. Biopsies were taken
from the greater curvatures of the antrum and middle body. H. pylori status
was assessed using culture and tissue section (Giemsa stain). Serial secti
ons were used for examination of gastritis (hematoxylin and eosin stain) an
d for immunostaining of p53, Ki-67 and myeloperoxidase (MPO). p53 index and
Ki-67 labeling index (LI) were calculated by counting p53-positive and Ki-
67-positive cells in the entire gastric pits longitudinally sectioned and e
xpressing them as a percentage of the total cells in a gastric pit. In the
neck regions with and without p53-positive cells, polymorphonuclear leukocy
tes (PMNs) were counted in the corresponding area (/50x50 mum(2)) of the se
ctions stained both with p53 and MPO.
Results. p53-positive cells decreased significantly after eradication of H.
pylori. Before eradication, the number of PMNs was significantly higher in
the neck regions with p53-positive cells than in those without.
Conclusions. In the gastric mucosa infected with H. pylori, p53-positive ce
lls were found in the neck region infiltrated with PMNs. p53 expression dec
reased significantly one month after eradication of H. pylori.