Diagnostic performance of gastric imprint smear for determination of Helicobacter pylori infection.

BACKGROUND

Despite the availability of several methods (invasive and noninvasive) for the diagnosis of Helicobacter pylori infection, no test is considered to be the 'gold standard'. Endoscopy-based tests are regarded as the reference method in most studies.

OBJECTIVE

To evaluate the diagnostic performance of imprint cytology smears of antral biopsies compared with Gram-stained smears, the rapid urease test and culture methods, separately and in combination.

METHODS

Antral biopsies were obtained from consecutive patients undergoing upper gastrointestinal endoscopy at a single centre. The biopsies were examined for the presence of H pylori by Gram-stained smear, the rapid urease test, culture methods and imprint cytology smear. 

RESULTS

A total of 273 biopsies were studied. All tests were positive in 36% of the patients. Of 252 biopsies tested, 73% were positive using the imprint cytology technique. Using Gram-stained smear, the rapid urease test and culture methods individually, the sensitivity and specificity of imprint cytology smears for the detection of H pylori were found to be 92.7% and 50%; 92.7% and 49%; and 92.4% and 38.5%, respectively. Combining the three microbiological methods resulted in a sensitivity of 92.1%, a specificity of 51.0% and an efficiency of 71.7% for imprint cytology smears.

CONCLUSIONS

Endoscopic examination provides useful clinical information. Imprint gastric cytology can be used as a rapid test to establish the diagnosis of H pylori infection at the time endoscopy is performed, enabling the endoscopist to start treatment with immediate effect.