Biotechnology Research Center, Pasteur Institute of Iran, No. 69, Pasteur Ave, 13164, Tehran, Iran.
Curr Microbiol. 2011 Jan;62(1):325-30. doi: 10.1007/s00284-010-9694-2. Epub 2010 Jul 23.
Helicobacter pylori (Hp) is a major risk factor for gastrointestinal disorders including gastric cancer. We evaluated host serum antibody responses toward outer membrane protein18 in comparison with Urease A and B subunits. omp18 and ureA-ureB gene fragments were PCR amplified, cloned, and expressed in E. coli expression system. The expressed proteins were visualized on SDS-PAGE and confirmed by immuno-blotting. Purified proteins were applied in western blotting assays in comparison with local and foreign ELISA kits. ROC curve analysis identified the optimum cut-off points for each protein. rOmp18 represented the highest rates of sensitivity (94%), specificity (89%), PPV (97.4%), NPV (77.4%), and accuracy (93.2%) in comparison with urease A and B subunits. These immunologic indices were in "substantial" agreement (Κ = 0.7) with the gold standard tests for Hp detection. This study recommends Hp conserved Omp18 as a reliable serologic marker for accurate detection of Hp infection particularly for application in population screening approaches.
幽门螺杆菌（Hp）是胃肠道疾病（包括胃癌）的主要危险因素。我们评估了宿主血清针对外膜蛋白 18 的抗体反应与尿素酶 A 和 B 亚基的抗体反应。omp18 和 ureA-ureB 基因片段通过 PCR 扩增、克隆和在大肠杆菌表达系统中表达。在 SDS-PAGE 上观察到表达的蛋白质，并通过免疫印迹进行确认。纯化的蛋白质与本地和外国 ELISA 试剂盒进行 Western blot 分析。ROC 曲线分析确定了每种蛋白质的最佳截止点。与尿素酶 A 和 B 亚基相比，rOmp18 在敏感性（94%）、特异性（89%）、PPV（97.4%）、NPV（77.4%）和准确性（93.2%）方面表现出最高的比率。这些免疫指标与 Hp 检测的金标准测试具有“高度”一致性（Κ=0.7）。本研究建议将 Hp 保守的 Omp18 作为一种可靠的血清学标志物，用于准确检测 Hp 感染，特别是在人群筛查方法中的应用。
