Diagnosis of Helicobacter Pylori Infection using Polymerase Chain Reaction in Gastric Biopsy Specimens

Helicobacter pylori infection is now recognized as a cause of chronic gastritis, peptic ulcer disease and is also a major risk factor for development of gastric carcinoma and gastric lymphoma. Several diagnostic methods of H. pylori infection, such as histopathology, Giemsa stain, culture, rapid urease test, urea breath test and serologic test have been used. Recently, the polymerase chain reaction(PCR) assay has provided a means of rapid and sensitive detection of H. pylori. This study aimed to evaluate PCR assay for the diagnosis of H. pylori infection.

I compared the PCR assay using the ureC gene specific for H. pylori with culture in gastric biospy specimens from 30 chronic gastritis, 10 gastric ulcer and 41 duodenal ulcer patients and evaluated the positive rates of H. pylori according to the gastroduodenal diseases.

Fifty-seven out of 81(70%) patients were culture positive and 64 out of 81(79%) patients were PCR positive. In seventy-two out of 81 patients, PCR was concordant with culture, but 8 patients had only positive-PCR and one patient had only positive-culture. Diagnostic sensitivity, specificity, positive predictive value, negative predictive value and diagnostic efficiency of culture were 85%, 100%, 100%, 58% and 88%, respectively and those of PCR were 96%, 100%, 100%, 82% and 96%, respectively. The positive rates of H. pylori using PCR were 73%, 90% and 80% and those using culture were 63%, 90% and 71% in chronic gastitis, gastric ulcer and duodenal ulcer patients, respectively.

These findings suggest that the PCR assay using the ureC gene in gastric biopsy is more sensitive and rapid than culture and an effective test for the diagnosis of H. pylori infection.