The Role of Direct Polymerase Chain Reaction in the Dection of Helicobacter pylori Infections

Roe, Im Hwan; Chin, Young Joo; Lee, Dae John; Lee, Moon Sook; Song, Il Han; Lim, Chang Yong; Kim, Jung Won; Yang, Mi Ra; Kim, Jung Taik; Seo, Eun Ok; Shin, Ji Hyun; Lee, Jong Hwa

Abstract

BACKGROUND AND AIMS: A variety of diagnostic procedures are available for the identification of Helicobacter pylori in clinical sarnples. Recently, the detection of H. pylori in gastric biopsy samples was attempted using polymerase chain reaction, in which primers based on the sequence of a species specific antigen of H. pylori were used. The aim of this study is to test whether the PCR is useful for the detection of H. pylori.
METHODS
Four hundred forty gastric biopsy samples were tested. Urease test was performed and then PCR using the primer of 298 bp sized 26 kDa antigen was taken in the same 2 pieces of gastric biopsy samples.
RESULTS
Total concordance rate between the urease test and direct PCR test was 85.9%. The concordance rate between the two tests were 80.2%, 88.5% and 88.8% in gastric cancer (n=86), gastric ulcer (n=78) and duodenal ulcer (n=161) respectively. The positive rates of the urease test and the direct PCR test were 36.0% and 44.2%, respectively in the gastric cancer, 56.4% and 55.1%, in the gastric ulcer, and 84.5% and 82.0% in the duodenal ulcer. The positive rate of H. pylori infection in the gastric cancer was lower than those of the other gastroduodenal diseases. CONCLUSIONS: Tbe PCR can detect H. pylori successfully in gastric biopsies using tbe 26 kDa antigen gene. The PCR technique have potential benefits of higher sensitivity and quicker detection than the urease test. Further study is necessary to establish PCR test as a diagnostic method of H. pylori and to elucidate the characteristics of H. pylori.