Comparison of a monoclonal antigen stool test (Hp StAR) with the 13C-urea breath test in monitoring Helicobacter pylori eradication therapy.
OBJECTIVE
To evaluate the agreement between a mAb-based stool test (HP StAR) and the urea breath test (UBT) in monitoring (H pylori) infection after eradication therapy.


METHODS
Patients with discordant results on UBT and Hp StAR underwent endoscopy with biopsies for rapid urease test, culture, and histology to confirm H pylori status.


RESULTS
Among 250 patients (50+/-14 years), 240 (96.0%) had concordant UBT and Hp StAR tests with a significant correlation between DOB and A values (R = 0.87; P<0.0001). The remaining 10 (4.0%) patients had discordant tests (positive Hp StAR and negative UBT) with the Hp StAR inaccurate in five cases (false positive) and UBT inaccurate in the other five cases (false negative). The "maximal expected" sensitivity, specificity, +PV, -PV, +LR, and -LR were 91%, 100%, 100%, 97.4%, infinity, and 8.2 respectively, for the UBT, and 100%, 97.4%, 91%, 100%, 38.8, and 0, respectively, for the Hp StAR. Overall accuracy for both tests was 98%.


CONCLUSIONS
Both the UBT and the Hp StAR are equally accurate in monitoring H pylori infection. Nowadays, the choice of the "best" non-invasive H pylori test in the post-treatment setting should be done not only in terms of diagnostic accuracy but also in view of cost and local facilities.
Perri
Francesco
F
Department of Internal Medicine, Casa Sollievo della Sofferenza Hospital, IRCCS, San Giovanni Rotondo, Italy. f.perri@operapadrepio.it
Quitadamo
Michele
M
Ricciardi
Rosalba
R
Piepoli
Ada
A
Cotugno
Rosa
R
Gentile
Annamaria
A
Pilotto
Alberto
A
Andriulli
Angelo
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D001944:Breath Tests; D005243:Feces / Q000737:chemistry*; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000517:prevention & control; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007159:Immunologic Tests / Q000191:economics / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D012680:Sensitivity and Specificity; D014508:Urea / Q000032:analysis*; D014510:Urease / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D014508:Urea; D014510:Urease