Background: Commercial serological tests for the detection of Helicobacter
pylori infection must be locally validated. We evaluated the accuracy of fi
ve commercial tests in the Chinese population.
Methods: Serum samples were collected from patients referred for upper endo
scopy. Antral biopsies were taken for histological examination and culture
of H. pylori. The gold standard for diagnosing H. pylori infection was posi
tive histological staining and/or positive H. pylori culture. The serum sam
ples were tested for H. pylori antibodies using the following tests: (i) Co
bas Core Anti-H. pylori EIA; (ii) GAP IgG; (iii) GAP IgM: (iv) H. pylori mi
crowell EIA (Ouidel): and (v) Premier H. pylori. The sensitivity, specifici
ty and accuracy of each test was calculated according to the manufacturers'
instructions or according to a new cut-off value.
Results: A total of 158 patients were recruited amongst whom 114 (72%) were
H. pylori-positive. Indeterminate results varied from 7% to 19%. The accur
acy of the tests varied from 57% to 85%. By using new cut-off values, the a
ccuracy was much improved, ranging from 73.4% to 86.7%.
Conclusions: By defining new cut-off values for the Chinese population, we
were able to improve the performance of some of the serology tests. This il
lustrates the importance of local validation.