Usefulness of brushing urease test for diagnosis of Helicobacter pylori infection.

BACKGROUND AND AIMS: Gastric brushing cytology is an accurate technique for rapidly detecting Helicobacter pylori infection, but it is not routinely employed since the presence of personnel experienced in this field, is necessary in the endoscopy suite. To evaluate the diagnostic usefulness of rapid urease test carried out on cytological brushing. PATIENTS: A total of 143 consecutive patients with suspected Helicobacter pylori infection, referred for elective gastroscopy.
METHODS: For each patient, 2 brushings were carried out and 4 biopsies were taken from antral mucosa during gastroscopy. The former brushing was smeared on a slide, and stained by a rapid staining set for blood smears. The latter was used for rapid urease test, by shaking the brush into the urea broth. Two biopsies were used for rapid urease test and two for histologic examination. Histology was considered as the gold standard.
RESULTS: Of 143 patients, 73 were diagnosed as Helicobacter pylori infected using histology. Six brushing slides were inadequate due to insufficient cytology material. Biopsy-rapid urease test and brushing-rapid urease test had similar sensitivity (87.3% vs 83.5%), specificity (98.4% vs 96.8%) and overall accuracy (92.3% vs 89.5%). In 62 Helicobacter pylori infected patients, both rapid urease test techniques were positive. Brushing-rapid urease test became positive in a significantly shorter time than biopsy-rapid urease test (22 +/- 54 minutes vs 39 +/- 63 minutes; p < 0.01).
CONCLUSIONS: Brushing-rapid urease test is as accurate as biopsy-rapid urease test in detecting Helicobacter pylori infection, but it is significantly faster. Special care should be taken to carry out brushing adequately, to minimize the occurrence of false negatives.