Evaluation of CLO test and polymerase chain reaction for biopsy-dependent diagnosis of Helicobacter pylori infection.

Helicobacter pylori is now recognized as possibly playing an etiologic role on the development of chronic gastritis, peptic ulcers and adenocarcinoma of the distal stomach. CLO test and polymerase chain reaction (PCR) assay are rapid, biopsy-dependent diagnostic tests for H. pylori identification. In this study, we assessed four diagnostic methods (CLO test, PCR assay, culture and histological examination) for H. pylori detection in biopsy specimens from 78 patients with gastroduodenal diseases and investigating the efficiency of CLO test and PCR assay for the diagnosis of H. pylori infection. H. pylori was identified in 75.6%, 75.6%, 64.1%, 69.2% of patients by CLO test, PCR assay, culture and histological examination, respectively. Compared with the detection of H. pylori by culture and/or histological examination, the sensitivity and specificity of the CLO test were 98.2% and 81.8%, respectively, whereas the sensitivity and specificity of PCR assay were 96.4% and 77.3%, respectively. According to the H. pylori infection state as determined from the results of three concordant tests, the sensitivities of culture, CLO test, histological examination, and PCR assay were 90.9%, 96.4%, 98.2% and 100%, respectively. Whereas, the specificity was 100%, 95%, 95% and 90% for culture, CLO test, histological examination, and PCR assay, respectively. We found that both CLO test and PCR assay were highly sensitive and specific for H. pylori identification; however, PCR assay was more sensitive than other methods for detecting the specimens after patients received treatment. The results of this study suggest that CLO test is a rapid and sensitive method of screening for H. pylori infection and that PCR assay could provide an accurate indication of the state of infection both during treatment for eradication of H. pylori and at follow-up.