[Evaluation of a western blot technique (Helicoblot 2.0) fpr the detection of specific Heliocobacter pylori antigens in children)].
BACKGROUND
The aim of this study was to evaluate the diagnosis usefulness of antibodies detection against different specific antigens of H. pylori (Hp) in children by a Western-blot commercially available (Helicoblot 2.0).


METHODS
96 symptomatic paediatric patients in two groups were studied. Group 1: 48 patients Hp positive by culture and/or histology (mean age, 10.19 +/- 3.40 years; 27 boys and 21 girls) and group 2: 48 patients Hp negative by both culture and histology (mean age, 9.31 +/- 3.15 years; 34 boys and 14 girls). Qualitative IgG detection against the protein antigens of 19.5 kD (urease E), 26.5 kD (urease D), 30 kD (urease H), 35 kD, 89 kD (vacuolating toxin VacA) and 116 kD (cagA protein) was determined by a Western-blot assay (Helicoblot 2.0, Genelabs, Singapore).


RESULTS
A specificity of 100% was obtained when reactivity against 19.5 kD protein (urease E) was considered alone. However, the best accuracy levels were observed with 26.5 kD (urease A) and 30 kD (urease H) antigens. An accuracy of 88.5% was observed when the manufacturer's recommended criteria was used (positivity of at least 116, 89 or 35 kD single bands or positivity of at least 2 bands of the 30, 26.5 or 19.5 kD).


CONCLUSIONS
Helicoblot 2.0 is a good method to diagnosis Hp infection in children. A criteria combining IgG against 2 urease antigens (preferentially urease A) or one urease antigen and a virulence associated protein (CagA o VacA) is recommended.
López-Brea
M
M
Servicio de Microbiología, Hospital Universitario de la Princesa, Madrid.
Alarcón
T
T
Domingo
D
D
Sánchez
I
I
Martínez
M J
MJ
Sanz
J C
JC
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D015153:Blotting, Western / Q000379:methods*; D002648:Child; D005069:Evaluation Studies as Topic; D005260:Female; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D008297:Male; D011933:Reagent Kits, Diagnostic; D014510:Urease / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D011933:Reagent Kits, Diagnostic; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D014510:Urease