© 2004 Blackwell Publishing Ltd, Helicobacter , 9, 657–662 657 Volume 9 • Number 6 • 2004 HELICOBACTER Blackwell Publishing, Ltd. Comparison of two Different Stool AntigenTests for the Primary Diagnosis of Helicobacter pylori Infection in Turkish Patients with Dyspepsia Y. Erzin, * S. Altun, † A. Dobrucali, * M. Aslan, † S. Erdamar, ‡ A. Dirican § and B. Kocazeybek † Departments of * Gastroenterology; † Microbiology and Clinical Microbiology; ‡ Pathology; § Biostatistics, Istanbul University, Cerrahpasa Medical Faculty, Istanbul, Turkey ABSTRACT Aim. To assess the reliability of two different enzyme immunoassays in detecting the Helicobacter pylori status in stool specimens of Turkish patients with dyspepsia. Materials and methods. One hundred and fifty-one patients [74 with nonulcer dyspepsia (NUD), 64 with duodenal ulcer (DU) and 13 with gastric cancer] who were admitted to the endoscopy unit of Istanbul University, Cerrahpasa Medical Faculty for upper gastrointestinal endoscopy because of dyspepsia were enrolled in the study. Helicobacter pylori infection was confirmed in all patients by histology, rapid urease test and culture. A patient was classified as being H. pylori-positive if the culture alone or both the histology and the rapid urease test were positive and as negative only if all of these tests remained negative. Stool samples were obtained from patients to assess the reliability of a monoclonal (FemtoLab H. pylori) and a polyclonal (Premier Platinum HpSA) stool antigen test and to compare the diagnostic accuracies of these two tests. A χ 2 test was used for statistical comparisons. Results. Using cut-off values of 0.19 for FemtoLab H. pylori and 0.16 for Premier Platinum HpSA, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 93%, 90%, 98%, 68% and 93% for the monoclonal test and 84%, 67%, 94%, 40% and 81% for the poly- clonal test, respectively. The sensitivity, specificity, negative predictive value and diagnostic accuracy of the monoclonal test were significantly greater than those of the polyclonal test (χ 2 = 3.98; p < .05 for sensitivity and χ 2 = 15.67; p = .000 for specificity, χ 2 = 15.78; p = .000 for negative predictive value and χ 2 = 6.37; p = .012 for diagnostic accuracy). The bacterial load did not affect the sensitivity of either test. Conclusions. The monoclonal FemtoLab H pylori test, using a cut-off 0.19, is a very sensitive, specific and easy to perform diagnostic tool for the primary diagnosis of H. pylori infection in Turkish patients with dyspepsia. Keywords. Helicobacter pylori, stool antigen test. S ince the discovery of Helicobacter pylori in 1983 the diagnosis and treatment of upper gastrointestinal disease have changed greatly. Helicobacter pylori is a common human patho- gen. It produces a gastric inflammatory process which may ultimately lead to the development of peptic ulcer disease or gastric carcinoma and The World Health Organization and the Interna- tional Agency for Research on Cancer consensus group stated in 1994 that there was sufficient epidemiologic and histologic evidence to classify H. pylori as a definite carcinogen [1]. As H. pylori has a world-wide distribution and can cause major health problems, scientists have been searching for new diagnostic tools to detect this micro-organism. A perfect test should be highly reliable, inexpensive and noninvasive. Although various tests are employed to detect H. pylori, there is no single gold standard and all of the tests have their pitfalls and limitations. Especially in developing countries, costs are forcing gastroenterologists and other clinicians to review the use of diagnostic methods, parti- cularly the use of invasive tests, in the manage- ment of H. pylori infection. Invasive methods, requiring the use of endoscopy, are expensive and inapplicable for a widespread population. Current guidelines for the management of H. pylori recommend the administration of Reprint requests to: Dr Bekir Kocazeybek Istanbul Univer- sity, Cerrahpasa Medical Faculty, Department of Micro- biology and Clinical Microbiology, Kocamustafapasa, Istanbul, Turkey. E-mail: bekirkcz@superonline.com