Gastric juice polymerase chain reaction: an alternative to histology in the diagnosis of Helicobacter pylori infection.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Helicobacter pylori serology in patients with chronic gastritis.

OBJECTIVES: Helicobacter pylori (Hp) infection is known to cause several gastroduodenal diseases. In patients with non-ulcer dyspepsia, we assessed the link between Hp infection and gastric mucosal inflammation, as well as the influence of Hp and inflammation on the serum levels of anti-Hp antibodies (IgG), pepsinogen A (PGA), pepsinogen C (PGC), and gastrin. METHODS: Entering the study were 221 patients with non-ulcer dyspepsia, all of whom underwent upper gastrointestinal endoscopy. RESULTS: Of the 221 patients investigated, 135 (61%) were Hp positive. The higher the bacterial load, the worse the associated gastritis, the gastric antrum and body being considered. All of the serological indices studied were found to be influenced by gastritis. Serum IgG satisfactorily discriminated between Hp-positive and Hp-negative subjects, with a sensitivity of 84% and a specificity of 86%. PGC, PGA, and gastrin were less accurate. Only PGC only found to be correlated with Hp load. The product of IgG and PGC improved the diagnostic accuracy of IgG alone. CONCLUSIONS: Hp infection, frequently found in patients with non-ulcer dyspepsia, is associated with gastric mucosal inflammation; of the indices studied, serum IgG and PGC most accurately indicated Hp infection, and their product may be proposed as an aid in diagnosing Hp infection in dyspeptic patients.

Helicobacter pylori infection enhances mucosal interleukin-1 beta, interleukin-6, and the soluble receptor of interleukin-2.

It is thought that Helicobacter pylori colonization of the gastric mucosa might stimulate the production of several cytokines, which might trigger and maintain the gastric inflammation associated with Helicobacter pylori infection. In the present study we evaluated interleukin-1 beta. interleukin-6, and the soluble receptor of interleukin-2 both in mucosal homogenates and in the sera of Helicobacter pylori-infected (39 cases) and uninfected (40 cases) patients to investigate whether there was any relationship between variations in cytokines and (1) the severity of Helicobacter pylori-associated gastritis or (2) CagA-positive Helicobacter pylori strains. Mucosal, but not serum levels of interleukins-1 and -6 and interleukin-2 receptor were significantly higher in infected than uninfected patients. Serum levels of Helicobacter pylori antibodies were significantly higher in infected than uninfected patients. These levels correlated with mucosal interleukin-1 beta. The degree of antral or body inflammatory grade was higher in infected than in uninfected patients; cytokines levels were higher in patients with high-grade gastritis, most of whom were Helicobacter pylori positive. Patients infected with CagA-positive strains also had higher levels of interleukin-1 beta, but not of interleukin-2 receptor or interleukin-6. In conclusion. Helicobacter pylori infection results in a local increase in interleukins-1 beta and -6 and interleukin-2 receptor associated with high-grade mucosal inflammation. Interleukin-1 beta seems to favor anti-Helicobacter pylori antibody production, and mucosal levels are enhanced mainly in patients infected with cytotoxic Helicobacter pylori strains.

Serum pepsinogen C: a useful marker of Helicobacter pylori eradication?

Medical treatment for Helicobacter pylori (Hp) infection is now recommended in several types of gastroduodenal disease, and its success is usually monitored by hystology. The end-points of our work were to identify the most suitable serum index of Hp eradication among pepsinogen A (PGA), pepsinogen C (PGC), PGA/PGC ratio, gastrin, and IgG anti-Hp (IGG). We studied a total of 289 Hp positive (Giemsa staining) patients, who were treated with 40 mg/day omeprazole (140 cases) or with 480 mg/day bismuth subsalicylate (149 cases) for 4 weeks. All the patients also received 1 g/day metronidazole + 2 g/day amoxycillin for the first 2 weeks of treatment. Two months after the end of therapy, the patient underwent a second endoscopy and Hp histological assessment: the infection was eradicated in 192 and still present in the remaining 97 subjects. Gastrin, PGA, PGC, and IGG were measured before and after therapy. All indices significantly decreased after therapy in eradicated patients, while PGA and gastrin significantly decreased after therapy in both eradicated and noneradicated patients, although in the latter group the variations were less pronounced. We calculated the per cent decrease of the studied indices. PGC, with a decrease of more than 25%, was found to be the most accurate biochemical index. Variation in PGC levels before and after treatment were correlated with corresponding variations in Hp bacterial load. In conclusion, between the different biochemical parameters evaluated, PGC showed the highest clinical efficiency.