Stool antigen tests in the diagnosis of Helicobacter pylori infection before and after eradication therapy.
OBJECTIVE
To evaluate two enzyme immunoassay-based stool antigen tests, Premier Platinum HpSA and Amplified IDEIA HpStAR, and one rapid test, ImmunoCard STAT! HpSA, in the primary diagnosis of Helicobacter pylori (H pylori) infection and after eradication therapy.


METHODS
Altogether 1 574 adult subjects were screened with a whole-blood H pylori antibody test and positive results were confirmed with locally validated serology and (13)C-urea breath test. All 185 subjects, confirmed to be H pylori positive, and 97 H pylori-negative individuals, randomly selected from the screened study population and with negative results in serology and UBT, were enrolled. After eradication therapy the results of 182 subjects were assessed.


RESULTS
At baseline, the sensitivity of HpSA and HpStAR was 91.9% and 96.2%, respectively, and specificity was 95.9% for both tests. ImmunoCard had sensitivity of 93.0% but specificity of only 88.7%. After eradication therapy, HpSA and HpStAR had sensitivity of 81.3% and 100%, and specificity of 97.0% and 97.6%, respectively. ImmunoCard had sensitivity of 93.8% and specificity of 97.0%. HpSA, HpStAR, and ImmunoCard had PPV 77%, 80%, and 75%, and NPV 98%, 100%, and 99%, respectively.


CONCLUSIONS
In primary diagnosis, the EIA-based tests performed well. After eradication therapy, negative results were highly accurate for all the three tests. HpStAR had the best overall performance.
Veijola
Lea
L
Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, PO Box 21, Fin-00014 Helsinki, Finland. lea.veijola@helsinki.fi
Myllyluoma
Eveliina
E
Korpela
Riitta
R
Rautelin
Hilpi
H
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000942:Antigens, Bacterial / Q000032:analysis; D001944:Breath Tests; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012698:Serologic Tests
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial