Gastric juice polymerase chain reaction: an alternative to histology in the diagnosis of Helicobacter pylori infection.
Infection from Helicobacter pylori plays a role in several gastroduodenal diseases. The recent availability of molecular techniques, particularly the polymerase chain reaction (PCR), allows us to detect small amounts of this bacterium. The aims of this study were to compare PCR and histological findings and to ascertain the clinical usefulness of H. pylori PCR identification in different biological samples. We studied 94 consecutive patients. Saliva, gastric juice, and four antral and four body biopsies were obtained from each patient. H. pylori was evaluated histologically in two antral and two body biopsies (Giemsa or Warthin-Starry stain). After extraction, DNA was submitted for PCR amplification using the two primers HPU1 and HPU2, which amplified a 411-bp product from the urease gene A. Forty-nine patients were H. pylori-positive at histological workup. The sensitivity of PCR was 92% for gastric juice, 73% for antral biopsies, 61% for body biopsies, and 13% for saliva. Of the 45 H. pylori-negative patients at histological assessment, 7 (16%) had positive findings on PCR, mainly when gastric juice was examined. These results indicate that PCR is as sensitive as histological assessment. We suggest that PCR H. pylori detection in gastric juice is a sensitive method for diagnosing this infection.