Accuracy of a monoclonal antibody-based stool antigen test in the diagnosis of Helicobacter pylori infection.
BACKGROUND
Recent availability of tests for Helicobacter pylori antigens in stool samples has provided potentially useful tools for epidemiological studies and clinical settings. The aim of this study was to evaluate a monoclonal antibody-based H. pylori antigen stool test in the primary diagnosis of H. pylori infection, and to study the test performance after patients were treated with lanzoprazole, and after eradication therapy.


METHODS
The study included 122 dyspeptic patients. At gastroscopy, biopsy specimens were obtained for culture and histology. Stool antigen and [14C]-urea breath tests were performed concurrently. Positive culture alone or a positive [14C]-urea breath test in combination with positive histology defined the reference standard. Forty-three Hp +ve patients were treated with lanzoprazole for 2 to 4 weeks, and stool antigen tests were performed on days 1 and 7 post-treatment. After eradication therapy, 32 patients were re-examined for H. pylori infection.


RESULTS
Prevalence of H. pylori was 44.3%. Sensitivity and specificity for the stool antigen test in the primary diagnosis of H. pylori infection were 98% and 94%, with positive and negative likelihood ratios of 16.7 and 0.02, respectively. All patients had positive stool tests immediately after lanzoprazole treatment, whereas 2 patients had negative stool tests after 7 days. Triple therapy rendered all patients stool test negative.


CONCLUSIONS
The monoclonal antibody-based stool antigen test is an accurate tool in the primary diagnosis of H. pylori infection and after eradication therapy. Lanzoprazole treatment does not influence the clinical performance of the test.
Asfeldt
A M
AM
Department of Gastroenterology, University Hospital of Northern Norway, NO-9038 Tromsø, Norway.
Løchen
M-L
ML
Straume
B
B
Steigen
S E
SE
Florholmen
J
J
Goll
R
R
Nestegard
O
O
Paulssen
E J
EJ
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy; D016480:Helicobacter pylori / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010437:Peptic Ulcer / Q000175:diagnosis / Q000382:microbiology; D054328:Proton Pump Inhibitors; D012680:Sensitivity and Specificity
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D009853:Omeprazole