Evaluation of stool antigen test, PCR on ORAL samples and serology for the noninvasive detection of Helicobacter pylori infection in children.
BACKGROUND
Endoscopy represents the gold standard for the diagnosis of Helicobacter pylori infection. We evaluated three noninvasive tests in a group of children: the immunoassay for detection of H. pylori stool antigen, the polimerase chain reaction for identification of bacterial DNA on the oral cavity and the serum specific antibodies.


METHODS
One hundred and ninety children underwent endoscopy for various gastrointestinal symptoms. H. pylori stool antigen and anti-H. pylori antibodies were assayed by commercial kits. The bacterial DNA on saliva and oral plaque was detected by a seminested PCR.


RESULTS
Based on the positivity of culture or urease rapid test and histology, infection was detected in 47 patients. The statistical analysis showed that, for the detection of the infection, stool antigen assay is more effective in sensitivity and negative predictive value (91.5% and 96.5%), whereas specificity and positive predictive values appear slightly better in serology (89.6% and 76.0%). Correlations between serum IgG both with patients' age (r = 0.21, p < .05) and H. pylori stool antigen (r = 0.47, p < .01) were found. The search for bacterial DNA on oral samples proved to be very specific (99.1% on saliva and 98.2% on plaque), but insensitive (22.2% and 25.7%). CONCLUSIONS. In children H. pylori stool antigen represents a sensitive test, suitable for detecting H. pylori infection. Serum IgG proved to be more specific; the PCR on the oral cavity resulted as being a very specific, but insensitive test.
Bonamico
Margherita
M
Istituto di Clinica Pediatrica, Università di Roma 'La Sapienza', Roma, Italy.
Strappini
Pier Michele
PM
Bonci
Enea
E
Ferri
Mirella
M
Crisogianni
Massimo
M
Guido
Mirka
M
Thanasi
Enina
E
Nenna
Raffaella
R
Macchia
Stefania
S
Luzzi
Ida
I
Magliocca
Fabio Massimo
FM
Mastromarino
Paola
P
D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000032:analysis; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D016133:Polymerase Chain Reaction; D011933:Reagent Kits, Diagnostic; D012463:Saliva / Q000382:microbiology; D012680:Sensitivity and Specificity; D014510:Urease / Q000032:analysis / Q000378:metabolism
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D004269:DNA, Bacterial; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D014510:Urease