The diagnostic accuracy of urine IgG antibody tests for the detection of Helicobacter pylori infection in Turkish dyspeptic patients

Background/aims: There is increasing interest in noninvasive tests for the assessment of Helicobacter pylori infection, and urine-based tests have been widely used as noninvasive tests to detect Helicobacter pylori infection. The aim of this study was to evaluate the adaptation and usefulness of urine antibody enzyme-linked immunosorbent assay and urine card tests in the clinical setting to detect anti-Helicobacter pylori IgG antibody excreted into urine in Turkish adult patients with dyspepsia. Materials and Methods: One-hundred twenty-four patients who were admitted and referred for upper endoscopy to Dokuz Eylul University Hospital, Gastroenterology Clinic were studied. Antrum and corpus biopsies were taken, and Helicobacter pylori status was defined in the presence of at least two positive results of rapid urease test, histopathology and culture. Urine and serum specimens of 124 patients were collected and examined for anti-Helicobacter pylori IgG antibody by URINELISA, RAPIRUN (Otsuka Pharmaceutical, Tokyo, Japan) and anti-Helicobacter pylori enzyme-linked immunosorbent assay (Euroimmun, Lubeck, Germany) tests, respectively. Results: Helicobacter pylori infection was positive in 82 (66.1%) patients according to the gold standard methods. Among 82 Helicobacter pylori infection-positive patients, 69 patients were positive by both URINELISA and RAPIRUN; 109 of 124 patients were positive by anti-Helicobacter pylori IgG enzyme-linked immunosorbent assay. The sensitivity and specificity of URINELISA, RAPIRUN and anti-Helicobacter pylori IgG enzyme-linked immunosorbent assay were 74.4%, 73.2%, 100% and 81.0%, 78.6%, 35.7%, respectively. However, the urine antibody test cut-off values were searched for the best concordance with the results of gold standard methods. This yielded that the sensitivity and specificity of URINELISA with our new cut-off value (0.530) were 90.2% and 71.4%, respectively. Conclusions: As a first study among Turkish adult patients with dyspepsia, the efficacy of URINELISA was related with the determination of a new cut-off value for pretreatment as a screening test value. We suggest that the cut-off value of the URINELISA test should be evaluated and considered for each patient group and each country. The URINELISA (OD 0.530) and RAPIRUN tests were found useful for the diagnosis of Helicobacter pylori infection in our patients with dyspepsia.