Validity of Polymerase Chain Reaction in the Diagnosis of Helicobacter pylori Infection Using Gastroscopic Bilpsy Specimens in Children

Cho, Yun Kyeong; Jung, Yang Sook; Lim, Jae Young; Kim, Yoon Ok; Choi, Myoung Bum; Park, Chan Hoo; Woo, Hyang Ok; Oh, Young Gyun; Youn, Hee Sang; Maeng, Kook Young; Ko, Gyung Hyuck; Park, Cheol Keun; Baik, Seung Cheol; Lee, Woo Kon; Cho, Myung Je; Rhee, Kwang Ho

Abstract

BACKGROUND AND AIMS: We tried to evaluate the clinical usefulness of the PCR for the diagnosis of H. pylori infection in children and to identify the possible false positive results by the PCR due to remaining H. pylori in the working channel of an endoscope or in the biopsy forceps.
METHODS
Forty seven urease test samples with three gastric biopsy specimens, 6 collections of 15 ml flushing distilled water after the end of working channel disinfection, l1 l5 ml-distilled-water batches as the negative controls, and one H. pylori positive paraffin block as the positive control were collected at the Gyeongsang National University Hospital. The Hel-2 primer set (GTGTGCGGGCTTACAAGGAT, CGTTAGCGTTCATCACACTC) and a 34 cycle amplification were used
RESULTS
All of the seventeen specimens of urease tested positive within 6 hours and the ten specimens of urease also tested positive within 48 hours were PCR positive. Eighteen of the 20 specimens of urease tested negative and were also PCR positive. Three of the 6 specimens of 15 ml flushing distilled water were found to be PCR positive. All the negative controls were PCR negative and the one positive control was PCR positive.
CONCLUSIONS
The clinical usefulness of PCR using gastric biopsy specimens in children was limited due to the possible dead or live H. pylori remaining in the biopsy channel.