W K Leung1, T P Chow, E K Ng, F K Chan, S C Chung, J J Sung. 1. Department of Medicine & Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong. wkleung@cuhk.edu.hk
Abstract
BACKGROUND: Performance of commercial serological tests for Helicobacter pylori varies in different populations, largely due to strain heterogeneity and variations in antigenic preparations. Currently available serology tests often show sub-optimal accuracy when used for Asian patients. AIM: This study evaluated a recombinant antigen-based immunoblot for the diagnosis of H. pylori infection in Chinese patients, and compared it with a conventional ELISA test. METHODS: Dyspeptic patients referred for diagnostic endoscopy were recruited. The gold standard for H. pylori infection was based on two or more positive results among rapid urease test, histology and (13)C-urea breath test. Serological diagnosis of H. pylori infection was conducted by an ELISA test (pylori DTect; Diagnostic Technology) and an immunoblotting against a novel recombinant antigen (C1S; Genelab), which was constructed by immunological screening of the genomic DNA library of H. pylori. RESULTS: A total of 87 patients were evaluated and H. pylori infection was diagnosed in 40 (46%) by the reference tests. The sensitivities of the ELISA and immunoblot were 80% (95% CI: 64--91%) and 90% (95% CI: 76--97%), whilst the specificities were 96% (95% CI: 86--96%) and 87% (95% CI: 74--95%), respectively. The respective likelihood ratios of the two tests were 18.6 and 7.0. CONCLUSIONS: Satisfactory performance is obtained by the use of the new recombinant antigen-based immunoblot for diagnosing H. pylori infection in Chinese patients.
BACKGROUND: Performance of commercial serological tests for Helicobacter pylori varies in different populations, largely due to strain heterogeneity and variations in antigenic preparations. Currently available serology tests often show sub-optimal accuracy when used for Asian patients. AIM: This study evaluated a recombinant antigen-based immunoblot for the diagnosis of H. pyloriinfection in Chinese patients, and compared it with a conventional ELISA test. METHODS: Dyspeptic patients referred for diagnostic endoscopy were recruited. The gold standard for H. pyloriinfection was based on two or more positive results among rapid urease test, histology and (13)C-urea breath test. Serological diagnosis of H. pyloriinfection was conducted by an ELISA test (pylori DTect; Diagnostic Technology) and an immunoblotting against a novel recombinant antigen (C1S; Genelab), which was constructed by immunological screening of the genomic DNA library of H. pylori. RESULTS: A total of 87 patients were evaluated and H. pyloriinfection was diagnosed in 40 (46%) by the reference tests. The sensitivities of the ELISA and immunoblot were 80% (95% CI: 64--91%) and 90% (95% CI: 76--97%), whilst the specificities were 96% (95% CI: 86--96%) and 87% (95% CI: 74--95%), respectively. The respective likelihood ratios of the two tests were 18.6 and 7.0. CONCLUSIONS: Satisfactory performance is obtained by the use of the new recombinant antigen-based immunoblot for diagnosing H. pyloriinfection in Chinese patients.
Authors: Yelda A Leal; Laura L Flores; Laura B García-Cortés; Roberto Cedillo-Rivera; Javier Torres Journal: PLoS One Date: 2008-11-18 Impact factor: 3.240