Comparison of stool immunoassay with standard methods for detection of Helicobacter pylori infection in patients with upper-gastrointestinal bleeding of peptic origin

Abstract

Objective To assess the accuracy of the determination of Helicobacterpyloriinfection by a stool immunoassay in patients with upper-gastrointestinal bleeding (UGB) of peptic origin, in comparison with the routine histological study, serology, rapid urease and13 C-breath tests. Methods Sixty-eight patients with endoscopically proven UGB of peptic origin were included. The presence ofH. pyloriwas considered when observed on histology or, if negative, by the positive indications of two of the remaining tests (serology, rapid urease, 13C-breath test). The accuracy of stool immunoassay was estimated according to results obtained with other diagnostic methods. Results Lesions causing gastrointestinal bleeding were 49 duodenal ulcers, 11 gastric ulcers, six pyloric channel ulcers, 13 acute lesions of the gastric mucosa, and 16 erosive duodenitis.H. pyloriinfection was present in 59 (86.76%) patients. Forty-one patients had received nonsteroidal anti-inflammatory drugs. The sensitivity and specificity of the diagnostic methods were 47.5% and 100% for the rapid urease test, 93% and 87.5% for the breath test, 86.4% and 77.7% for serology, 89.4% and 100% for histology, and 96.6% and 33.3% for the stool test. Conclusions The detection ofH. pyloriantigen in stools in patients with UGB of peptic origin has a good sensitivity (96.6%) but a low specificity (33.3%) for the diagnosis of H. pylori infection, which probably makes this test an inadequate tool in this setting if utilized alone.