Higher frequency of cagA EPIYA-C phosphorylation sites in H. pylori strains from first-degree relatives of gastric cancer patients.
BACKGROUND
To evaluate the prevalence of more virulent H. pylori genotypes in relatives of gastric cancer patients and in patients without family histories of gastric cancer.


METHODS
We evaluated prospectively the prevalence of the infection by more virulent H. pylori strains in 60 relatives of gastric cancer patients comparing the results with those obtained from 49 patients without family histories of gastric cancer. H. pylori status was determined by the urease test, histology and presence of H. pylori ureA. The cytotoxin associated gene (cagA), the cagA-EPIYA and vacuolating cytotoxin gene (vacA) were typed by PCR and the cagA EPIYA typing was confirmed by sequencing.


RESULTS
The gastric cancer relatives were significant and independently more frequently colonized by H. pylori strains with higher numbers of CagA-EPIYA-C segments (OR = 4.23, 95%CI = 1.53-11.69) and with the most virulent s1m1 vacA genotype (OR = 2.80, 95%CI = 1.04-7.51). Higher numbers of EPIYA-C segments were associated with increased gastric corpus inflammation, foveolar hyperplasia and atrophy. Infection by s1m1 vacA genotype was associated with increased antral and corpus gastritis.


CONCLUSIONS
We demonstrated that relatives of gastric cancer patients are more frequently colonized by the most virulent H. pylori cagA and vacA genotypes, which may contribute to increase the risk of gastric cancer.
Laboratory of Research in Bacteriology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Dulciene M M
DM
Queiroz
Cícero I S M
CI
Silva
Maria H R B
MH
Goncalves
Manuel B
MB
Braga-Neto
Andréa B C
AB
Fialho
André M N
AM
Fialho
Gifone A
GA
Rocha
Andreia M C
AM
Rocha
Sérgio A
SA
Batista
Richard L
RL
Guerrant
Aldo A M
AA
Lima
Lucia L B C
LL
Braga
D000328:Adult; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002277:Carcinoma / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D005190:Family; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010766:Phosphorylation; D015995:Prevalence; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D014510:Urease / Q000032:analysis
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D014510:Urease