Prevalence of Helicobacter pylori infection and clinical efficiency of serological investigation

Background; Helicobacter pylori has been associated with various gastroduodenal diseases, in particular chronic type B gastritis. It is also an important risk factor for peptic ulcer and gastric carcinoma. Methods; In this study we ascertained: a) the prevalence of H. pylori infection in patients submitted to endoscopy with biopsy, and b) the clinical efficiency of the measurement of immunoglobulin G antibody to H. pylori (HELORI test) compared with the golden standard (histology) and the urease test. Results: Overall, at histology 300 out of 432 patients (10%) were positive for H. pylori; of these 300, 244 were also positive at serology. The prevalence of H. pylori infection was higher in subjects over 60 years of age. On the contrary, no specific antibodies were found in 81 out of 132 patients who at histology were negative for N. pylori. The sensitivity, specificity, and overall efficiency of serology were 84%, 64% and 75%, respectively. The clinical efficiency of serology was higher when agreement between the results of at least two of the three diagnostic tests for H. pylori was used as the reference value for comparison studies. Only 20% of H. pylori-positive subjects were found to have normal gastric mucosa at endoscopy and histology. On the other hand, in these patients a high prevalence of duodenal ulcer and chronic gastritis was found. Conclusions: We demonstrated a significant prevalence of infection from H. pylori in our population of patients with gastrointestinal disease. The clinical efficiency of serology is quite satisfactory, in particular using as reference value the concordance of at least two diagnostic tests for H. pylori.