[Association among anti-CagA antibody detection, antibiotic susceptibility, and peptic ulcer in patients with Helicobacter pylori infection].
BACKGROUND
The aim of this study was to determine the relationship among antibodies against virulence factors (CagA and VacA), clinical status and primary resistance in dyspeptic patients with Helicobacter pylori infection.


METHODS
Ninety-eight adult patients with Helicobacter pylori infection who underwent gastric endoscopy for dyspepsia were studied. Specific serum IgG antibodies against CagA and VacA proteins were detected by Western-blot (Helicoblot 2.0). Minimum inhibitory concentrations of metronidazole, amoxicillin, tetracycline and clarithromycin were determined with the E-test.


RESULTS
Thirty-nine patients presented peptic ulcer disease and 59 had non-ulcer dyspepsia. CagA protein was detected in 63 patients, and VacA protein in 52 subjects, and both were significantly associated with peptic ulcers (p 5 0.034 and p 5 0.029, respectively). Susceptibility results showed 38.8% of strains resistant to metronidazole and 10.3% resistant to clarithromycin. No resistance to amoxicillin or tetracycline was found. Susceptibility to clarithromycin was more frequent in ulcer patients than in non-ulcer dyspepsia patients (p 5 0.046). CagA protein was more frequent in patients with clarithromycin-sensitive strains (p < 0.001).


CONCLUSIONS
Antibodies against CagA protein were associated with higher antibiotic susceptibility in patients with ulcers or non-ulcer dyspepsia. Thus, anti-CagA antibody detection could be a useful marker of favorable prognosis with antibiotic treatment.
Toro
Carlos
C
Servicio de Enfermedades Infecciosas. Hospital Carlos III. Madrid. España. carlostororueda@hotmail.com
García-Samaniego
Javier
J
Alarcón
Teresa
T
Baquero
Margarita
M
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D017291:Clarithromycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004415:Dyspepsia / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010437:Peptic Ulcer / Q000382:microbiology*; D011379:Prognosis; D014774:Virulence
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori; D008795:Metronidazole; D017291:Clarithromycin