Accuracy of seven different tests for the diagnosis of Helicobacter pylori infection and the impact of H2-receptor antagonists on test results.
BACKGROUND
In this study we compared the accuracy of seven diagnostic tests in diagnosing Helicobacter pylori infection.


METHODS
Over 1 year 351 consecutive dyspeptic patients were tested for H. pylori infection by means of antral biopsy specimens for the rapid urease test (RUT), culture, microscopy (acridine stain), and the laboratory urease test (LUT) and, in addition, with 14C urea breath test (UBT), IgG serology, and IgA serology (Orion Diagnostica Pyloriset New EIA-G and New EIA-A). The criterion for H. pylori infection was a minimum of three positive tests. Before being tested, 38% of the patients had used an H2-receptor antagonist (H2RA).


RESULTS
Two-hundred and twenty-four patients (64%) were H. pylori-positive. The sensitivity and specificity of the tests were as follows (percentages): RUT, 85, 99; culture, 93, 100; microscopy, 81, 98; LUT, 80, 100; UBT, 95, 95; IgG serology, 99, 91; and IgA serology, 88, 91. The accuracy of the RUT and LUT was reduced in patients receiving H2RA therapy (P=0.04 and 0.01, respectively).


CONCLUSIONS
Culture, UBT, and IgG serology were all superior to the other four tests in diagnosing H. pylori infection. Invasive urease-based tests were less accurate in patients receiving H2RAs.
Lerang
F
F
Dept. of Internal Medicine, Ostfold Central Hospital, Fredrikstad, Norway.
Moum
B
B
Mowinckel
P
P
Haug
J B
JB
Ragnhildstveit
E
E
Berge
T
T
Bjørneklett
A
A
D001706:Biopsy; D001944:Breath Tests; D015169:Colony Count, Microbial; D004415:Dyspepsia / Q000188:drug therapy / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D016480:Helicobacter pylori / Q000254:growth & development / Q000302:isolation & purification*; D006635:Histamine H2 Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000188:drug therapy / Q000382:microbiology*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D006635:Histamine H2 Antagonists