Evaluation of blood tests to predict normal gastric mucosa

Background: To determine the accuracy of blood tests in predicting normal gastric mucosa confirmed by histological examination of gastric biopsy specimens. Methods: In total, 207 consecutive patients referred for upper endoscopy were included. Two biopsy specimens each from the antrum and corpus were assessed histologically for the presence of Helicobacter pylori, gastritis, and atrophy. Serum samples were studied for H. pylori antibodies by enzyme immunoassay (Pyloriset EIA-G and EIA-A) and by a rapid latex agglutination test (Pyloriset Dry); pepsinogen I was measured by an immunoenzymometric assay (Gastroset PGI), gastrin by radioimmunoassay, and parietal cell antibodies by indirect immunofluorescence. Results: In 101 (49%) of 207 patients, the gastric mucosa on histologic examination was normal. In the 63 patients aged 45 years or less, H. pylori IgG serology was negative in all 47 patients with normal gastric mucosa and none had low serum pepsinogen I levels. Among 144 patients over age 45 years, 72 had negative H. pylori IgG serology. Combining the serum pepsinogen I assay with the results of H. pylori IgG serology, 12 patients with normal serology but low serum pepsinogen I were found. Thus, 60 patients, 52 of whom showed normal gastric histology, had normal IgG serology and serum pepsinogen I. In the remaining eight patients with normal blood tests, the histologic changes were very mild. Conclusions: Although negative H. pylori IgG serology alone in younger patients, and in combination with normal serum pepsinogen I levels in older patients, reliably predicted the presence of normal gastric mucosa, gastroscopy is still recommended for patients over 45 years.