Validación de un test de ureasa para diagnóstico de helicobacter pylori en comparación con el clotest y en referencia a la histología

Abstract

Non commercial ureasa tests are used to detect Helicobacter pylori. They have the advantage of its low cost. The necessity has been revised of carrying out clinical studies that validate them appropriately, in the places where they are used. Objective. To validate a preparation of ureasa test made in our unit ("laboratory test") in comparison with CLOtest and histologic result. Methods. prospective, randomized study of ureasa tests validation and results comparison, in patients with digestives symptoms and endoscopy indication. Random gastric antral biopsies were performed for the CLO-test and the lab test. In addition, two biopsies were performed for the histological study. We excluded patients who had recently taken medication that could change the HP diagnosis. The evaluation of the results was independently carried out. Results. 105 patients were included (mean age 45.43 ± 17 DS). 70.4% tested positive on the histological exam, whereas 65.8% and 64.3% tested positive on the CLOtest and on the lab test respectively: these differences were not statiscaly significants (p>0,05). The global value of the laboratory test was 93.33% (95% IC: 86.27 – 97.04); with 7 false negative and no false positive. The sensibility, specificity, value positive and negative predictive values were 90.54%, 100%, 100% and 81.57% respectively. The results of the CLOtest were similar: global value of 95.23% (95% IC: 88.70 – 98.23); 5 false negative and no false positives. The sensibility, specificity, value positive and negative predictive values were 93,24%, 100%, 100% and 86,11% respectively. None of the parameters showed significant differences (p>0.05). The reaction times of the tests were similar. Conclusion. The validation of our laboratory test provided similar results to the CLOtest.