Study On The Clinical Application Of Detection Of Helicobacter Pylori Stool Antigen

[Background and Aims]This paper showed that epidemiological survey was made to indicate that H.pylori infection was a common disorder with high morbidity in the world. H.pylori research had been at a molecular biology level. The relationship between colonization and virulence factor of H.pylori, and Chronic gastritis, peptic ulcer, gastro esophageal reflux disease, gastric lymphoma of mucosa-associated lymphoid tissue and extra-gastrointestinal tract diseases was investigated from the perspective of H.pylori genetically. Human beings were the infection source of H.pylori. Although the H.pylori chould be eliminated from the body, the carriers of the infection were unclear.It was vital to apply accurate method for the diagnosis of H.pylori infection diagnosis and treatment. How a simple and accuratly detection of H.pylori was used for the diagnosis of H.pylori infection was the main concern of international scholars. 13C-urea breath test (13C-UBT) was the standard for the diagnosis of H.pylori infection and was used widely because of it was non-invasive and high efficiency. However, there were still some factors which restrict the clinical application of 13C-UBT, for example:expensive costs of detection and equipment, unsuitable for the epidemiological survey, limited accuracy in patients with subtotal gastrectomy, poor compliance in old and children and patients with mental symptoms. Helicobacter pylori Stool Antigen (HpSA) test was a new and non-invasive H.pylori detection technology which obtains samples from out of the stomach. H.pylori settled on the surface of gastric epithelial cells renewing fast and excreted from the body by feces accompany with cast-off cells. So HpSA test could become a method for diagnosis of H.pylori infection. This study was to assess the efficacy of Helicobacter pylori Stool Antigen (HpSA) test for detection of H.pylori infection.[Methods]The stool specimens collected from 353 patients with upper gastrointestinal symptoms were detected for HpSA by enzyme linked immune sorbent assay (Produced by different H.pylori antigen Kit).The diagnostic accuracy of HpSA by ELISA was evaluated by compared with the results of 13C-urea breath test (13C-UBT) which was defined as gold standard. ROCKIT for windows 1.1βsoftware and SPSS 15.0 software package were used to analyze the data. The relative operating characteristic (ROC) curve was constructed by using parametric distribution-free approach (PDF) and non-parametric method. The area under the ROC curve was used to evaluate the value of HpSA test in diagnosis of H.pylori infection.[Results] 1. The chi-square test showed that positive H.pylori infection was detected in 169 cases by ELISA (Kit 1:XIEHE pharmaceuticals company),177 by 13C-UBT with no significant difference (P>0.05). The sensitivity and specificity of the HpSA by ELISA were 92.66% and 97.20%, respectively; Youden's index=0.90, Kappa=0.90; The area under the ROC curve for ELISA detection of HpSA was 0.96 by PDF and 0.95 by non-parametric method.2. The chi-square test showed that positive H.pylori infection is detected in 170 cases by ELISA (Kit 2:DIAGNOSTEC international company),177 by 13C-UBT with no significant difference (P>0.05). The sensitivity and specificity of the HpSA by ELISA were 94.35% and 98.30%, respectively; Youden's index=0.93, Kappa=0.93; The area under the ROC curve for ELISA detection of HpSA was 0.97 by PDF and 0.94 by non-parametric method.3. The chi-square test showed that positive H.pylori infection was detected in 169 cases by Kit 1,170 cases by Kit 2 with no significant difference (P>0.05), The coincidence of Kitl and Kit2 in detection of HpSA was 98.58%, Kappa=0.97; The area under the ROC curves were significant higher for detecting HpSA by Kitl and Kit2 than 0.5 which serves as a reference of a test with no diagnostic value curve (P＜0.001); The correlation of area under the ROC curve between Kit 1 and Kit 2 was 0.61; The difference between them was not significant (P>0.05). The results about equivalence test were that they had the equal areas (P＜0.001), and then indicated that two tests had the equal accuracy to diagnosis of H.pylori infection, and also provided important evidence for the application of the clinically.[Conclusion]The Helicobacter pylori stool test (HpSA) is a simple, non-invasive method which is worth spreading in the clinical practice to determin of H.pylori infection; ELISA assay is better in high accurate reliable and stable test for the diagnosis of H.pylori infection.