Usefulness of anti-Helicobacter pylori and anti-CagA antibodies in the selection of patients for gastroscopy.

Screening of dyspeptic patients with serological tests for Helicobacter pylori before open-access gastroscopy has been suggested to be worthwhile. CagA-positive H. pylori strains may be associated with major pathology more often than CagA-negative strains. The usefulness of anti-H. pylori and anti-CagA antibodies in screening for gastroscopy was evaluated in unselected dyspeptic patients.Four hundred consecutive, unselected dyspeptic patients (mean age, 56.8 yr) in primary care were investigated with gastroscopy, ultrasonography of the upper abdomen, laboratory tests (including serological tests for H. pylori and CagA), and other examinations if needed. The patients were followed for 1 yr.Results of serological tests were positive for H. pylori in 56.2% of patients, of whom 64.4% also had results positive for CagA. Use of H. pylori and CagA serology-based screening combined with a history of nonsteroidal anti-inflammatory drug use would have detected only 80 and 70% of the major pathologies (peptic ulcer, moderate or severe esophagitis, celiac disease, or malignancy), respectively, in these patients. Gastroscopy would have been avoided in 30 and 41%, respectively, if only patients who had positive results on serological tests or who were nonsteroidal anti-inflammatory drug users would have been referred. In patients younger than 45 yr of age (n = 87), 60-74% of gastroscopies would have been avoided, but 50-60% of major pathologies would have been missed, by using the screening strategy studied. One of the nine malignancies (all in patients >45 yr of age) was H. pylori-negative, and two were CagA-negative.Anti-CagA antibodies do not offer advantages compared with anti-H. pylori antibodies in screening patients for gastroscopy. A remarkable share of major pathologies are missed by both of these screening methods. Therefore, the results of these screening tests are not recommended as selective criteria for gastroscopy.