Accuracy of monoclonal stool tests for determining cure of Helicobacter pylori infection after treatment.
BACKGROUND
Studies comparing new monoclonal fecal tests for evaluating cure of Helicobacter pylori infection after treatment are scarce. The objective was to compare the diagnostic accuracy of three monoclonal stool tests: two rapid in-office tools -RAPID Hp StAR and ImmunoCard STAT! HpSA - and an EIA test - Amplified IDEIA Hp StAR.


METHODS
Diagnostic reliability of the three tests was evaluated in 88 patients at least 8 weeks after H. pylori treatment. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated.


RESULTS
All tests presented similar performance for post-eradication testing. Sensitivity for detecting persistent infection was 100% for both Amplified IDEIA and RAPID Hp StAR and 90% for ImmunoCard STAT! HpSA. Respective specificities were 94.9%, 92.3-93.6% and 94.9%. Negative predictive values were very high (100%, 100% and 98.7% respectively). But positive predictive values were lower, ranging from 62.5 to 71.4%.


CONCLUSIONS
All monoclonal fecal tests in this series presented similar performance in the post-treatment setting. A negative test after treatment adequately predicted cure of the infection. However, nearly a third of tests were false positive, showing a poor predictive yield for persistent infection.
Calvet
Xavier
X
Hospital de Sabadell, Institut Universitari Parc Taulí, Departament de Medicina, Universitat Autònoma de Barcelona, Spain. xcalvet@tauli.cat <xcalvet@tauli.cat>
Lario
Sergio
S
Ramírez-Lázaro
María José
MJ
Montserrat
Antònia
A
Quesada
Mariela
M
Reeves
Lynsey
L
Masters
Helen
H
Suárez-Lamas
David
D
Gallach
Marta
M
Miquel
Mireia
M
Martínez-Bauer
Eva
E
Sanfeliu
Isabel
I
Segura
Ferran
F
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D016903:Drug Monitoring / Q000379:methods*; D005189:False Positive Reactions; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal