Gastric juice for the diagnosis of H pylori infection in patients on proton pump inhibitors.
OBJECTIVE
To determine the efficacy of gastric juice polymerase chain reaction (PCR) for the detection of H pylori infection in comparison with histology and gastric antral biopsy PCR in patients on a proton pump inhibitor (PPI).


METHODS
Eighty-five consecutive patients with dyspeptic symptoms were enrolled. Gastric biopsies for histology, PCR and gastric juice were collected at endoscopy for PCR of the H pylori urease C gene (ure C). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive and negative likelihood ratio for PCR of gastric juice for the H pylori ure C gene was compared to histology and gastric antral biopsy H pylori ure C PCR in patients with and without PPI.


RESULTS
Gastric juice PCR was positive in 66 (78%) patients. Histology showed H pylori associated gastritis in 57 (67%). Gastric biopsy PCR was positive in 72 (85%). In patients not taking PPI, the sensitivity, specificity, PPV, NPV, accuracy and positive and negative likelihood ratio for gastric juice PCR were 89%, 72%, 91%, 67%, 90%, 85%, 3.1 and 0.1 respectively. In patients on PPI these values were 86%, 100%%, 100%, 29%, 86%, 9.5 and 1.4, respectively.


CONCLUSIONS
Gastric juice PCR for the diagnosis of H pylori infection has increased sensitivity compared to histology with PPI. The use of gastric juice PCR is recommended to confirm H pylori status in patients taking PPIs.
Yakoob
Javed
J
Section of Gastroenterology, Department of Medicine, Aga Khan University Hospital, Stadium Road, Karachi 74800, Pakistan. yakoobjaved@hotmail.com
Rasool
Shahid
S
Abbas
Zaigham
Z
Jafri
Wasim
W
Abid
Shahab
S
Islam
Muhammad
M
Ahmad
Zubair
Z
D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D004269:DNA, Bacterial / Q000378:metabolism; D005260:Female; D005750:Gastric Juice / Q000201:enzymology* / Q000382:microbiology*; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000201:enzymology; D016480:Helicobacter pylori / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D054328:Proton Pump Inhibitors / Q000627:therapeutic use*; D011706:Pyloric Antrum / Q000201:enzymology / Q000382:microbiology / Q000473:pathology; D012680:Sensitivity and Specificity; D014510:Urease / Q000235:genetics* / Q000378:metabolism
D004269:DNA, Bacterial; D054328:Proton Pump Inhibitors; D014510:Urease