Effect of proton-pump inhibitor therapy on diagnostic testing for Helicobacter pylori.
BACKGROUND
Proton-pump inhibitor therapy may cause false-negative results on Helicobacter pylori diagnostic testing.


OBJECTIVE
To determine the frequency and duration of conversion of urea breath test results from positive to negative in patients given a proton-pump inhibitor.


METHODS
Two urban university gastroenterology clinics.


METHODS
Patients infected with H. pylori who had positive results on urea breath tests.


METHODS
Lansoprazole, 30 mg/d for 28 days.


METHODS
The urea breath test was repeated at 28 days. If the results were negative, testing was repeated 3, 7, 14, and 28 days after completion of therapy until the results reverted to positive.


RESULTS
31 (33%) of 93 patients in whom H. pylori was not eradicated had a negative breath test result while receiving lansoprazole. The proportions of patients whose breath test results were positive after completion of lansoprazole therapy were 91% (95% CI, 83% to 96%) at 3 days, 97% (CI, 90% to 99%) at 7 days, and 100% (CI, 96% to 100%) at 14 days.


CONCLUSIONS
Patients should not receive proton-pump inhibitors for 2 weeks before receiving the urea breath test for H. pylori infection.
University of Southern California School of Medicine, Los Angeles 90033, USA.
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Laine
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Estrada
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Trujillo
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Knigge
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Fennerty
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents / Q000627:therapeutic use*; D001944:Breath Tests; D003951:Diagnostic Errors; D005188:False Negative Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011446:Prospective Studies; D054328:Proton Pump Inhibitors; D014508:Urea / Q000032:analysis
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D014508:Urea; D009853:Omeprazole