BACKGROUND/AIMS: To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue. METHODS: A total of 107 volunteers were enrolled. All subjects underwent a 13C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens. RESULTS: H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 +/- 646.7 and 604.3 +/- 594.3 mumol/L (p > 0.05), and pH was 3.37 +/- 1.64 and 2.82 +/- 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia. CONCLUSIONS: HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.
Adult ; Antibodies, Monoclonal/*immunology ; Bacterial Proteins/*analysis/immunology ; Biomarkers/analysis ; Biopsy ; False Negative Reactions ; False Positive Reactions ; Female ; Gastritis, Atrophic/*diagnosis/microbiology ; Helicobacter Infections/*diagnosis/microbiology ; Helicobacter pylori/*enzymology/immunology ; Humans ; *Immunologic Tests ; Male ; Metaplasia ; Middle Aged ; Predictive Value of Tests ; Pyloric Antrum/*microbiology/pathology ; Reproducibility of Results ; Time Factors ; Urease/*analysis/immunology ; Workflow

We tested correlations between anti-Helicobacter pylori IgG and IgA levels and the urease test, anti-CagA protein antibody, degree of gastritis, and age. In total, 509 children (0-15 years) were enrolled. Subjects were stratified as 0-4 years (n = 132), 5-9 years (n = 274), and 10-15 years (n = 103) and subjected to the urease test, histopathology, ELISA, and western blot using whole-cell lysates of H. pylori strain 51. The positivity rate in the urease test (P = 0.003), the degree of chronic gastritis (P = 0.021), and H. pylori infiltration (P < 0.001) increased with age. The median titer for anti-H. pylori IgG was 732.5 IU/mL at 0-4 years, 689.0 IU/mL at 5-9 years, and 966.0 IU/mL at 10-15 years (P < 0.001); the median titer for anti-H. pylori IgA was 61.0 IU/mL at 0-4 years, 63.5 IU/mL at 5-9 years, and 75.0 IU/mL at 10-15 years (P < 0.001). The CagA-positivity rate was 26.5% at 0-4 years, 36.5% at 5-9 years, and 46.6% at 10-15 years for IgG (P = 0.036), and 11.3% at 0-4 years, 18.6% at 5-9 years, and 23.3% at 10-15 years for IgA (P < 0.001). Anti-H. pylori IgG and IgA titers increased with the urease test grade, chronic gastritis degree, active gastritis, and H. pylori infiltration. Presence of CagA-positivity is well correlated with a high urease test grade and high anti-H. pylori IgG/IgA levels.
Adolescent ; Antibodies, Bacterial/*blood ; Antigens, Bacterial/*analysis/immunology ; Bacterial Proteins/*analysis/immunology/metabolism ; Blotting, Western ; Child ; Child, Preschool ; Chronic Disease ; Enzyme-Linked Immunosorbent Assay ; Female ; Gastritis/pathology ; Helicobacter Infections/blood/microbiology/*pathology ; Helicobacter pylori/isolation & purification/*metabolism ; Humans ; Immunoglobulin A/*blood ; Immunoglobulin G/*blood ; Infant ; Infant, Newborn ; Male ; Severity of Illness Index ; Urease/metabolism