Barbosa J, Dinis-Ribeiro M, Guilherme M, Filipe T, Lomba-Viana R, Guimarães M A, Lopes C
Department of Microbiology, Portuguese Oncology Institute, Porto, Portugal.
Br J Biomed Sci. 2003;60(4):175-9. doi: 10.1080/09674845.2003.11783695.
It is believed that Helicobacter pylori acts mainly during the initial phases of gastric carcinogenesis. Therefore, this study aims to assess the usefulness of H. pylori diagnosis in patients with chronic gastritis (CG), intestinal metaplasia (IM) and dysplasia--conditions that are associated with gastric cancer. A cross-sectional study of 94 patients was performed, which involved endoscopic biopsy and determination of specific serum anti-H. pylori antibodies (IgA, IgG and IgM) by enzyme-linked immunosorbent assay (ELISA). Biopsies were taken from the gastric antrum and corpus, and from endoscopic lesions. Two specimens per patient were used for bacterial culture. H. pylori infection status, used as the gold standard, was based on culture results. Validity measures were determined and receiver operating curve (ROC) was used to determine the best cut-off for serum antibody levels. Histopathological evaluation (n = 160) was performed independently by two pathologists. Lesions consistent with CG were found in 86 patients (91%), consistent with IM in 69 patients (73%) and with dysplasia in five patients (5%). In the 86 patients with CG, 38 (44%) were infected by H. pylori, as were 26 (38%) and one (20%) with IM and dysplasia, respectively (P=0.039). Area under the curve (AUC) was 0.40 (95% confidence interval [CI]: 0.28-0.51) for IgM, 0.69 (0.58-0.80) for IgA and 0.83 (0.74-0.92) for IgG for the diagnosis of H. pylori infection. Best cut-off was 41 u/mL for IgG, with a sensitivity (95% CI) of 90% (84-96%) and a negative predictive value (NPV) of 91% (85-97%). For IgA the results were 22 u/mL, 74% (65-83%) and 77% (68-86%), respectively. Prevalence of H. pylori appeared to decrease with increasing severity of the gastric lesion. In conclusion, it is suggested that non-invasive serological evaluation of anti-H. pylori (IgG) status after eradication therapy for peptic ulcer disease could be extended, after proper assessment of cut-off values and their validation, to the follow-up of patients with CG and IM.
据信，幽门螺杆菌主要在胃癌发生的初始阶段起作用。因此，本研究旨在评估幽门螺杆菌诊断在慢性胃炎（CG）、肠化生（IM）和发育异常患者中的实用性，这些病症都与胃癌相关。对94例患者进行了横断面研究，包括内镜活检以及通过酶联免疫吸附测定（ELISA）测定特异性血清抗幽门螺杆菌抗体（IgA、IgG和IgM）。活检取自胃窦和胃体以及内镜病变处。每位患者取两份标本用于细菌培养。以培养结果作为金标准确定幽门螺杆菌感染状态。确定有效性指标，并使用受试者工作特征曲线（ROC）确定血清抗体水平的最佳临界值。由两位病理学家独立进行组织病理学评估（n = 160）。86例患者（91%）发现有符合CG的病变，69例患者（73%）符合IM，5例患者（5%）符合发育异常。在86例CG患者中，38例（44%）感染了幽门螺杆菌，IM患者中有26例（38%）感染，发育异常患者中有1例（20%）感染（P = 0.039）。诊断幽门螺杆菌感染时，IgM的曲线下面积（AUC）为0.40（95%置信区间[CI]：0.28 - 0.51），IgA为0.69（0.58 - 0.80），IgG为0.83（0.74 - 0.92）。IgG的最佳临界值为41 u/mL，敏感性（95% CI）为90%（84 - 96%），阴性预测值（NPV）为91%（85 - 97%）。IgA的结果分别为22 u/mL、74%（65 - 83%）和77%（68 - 86%）。幽门螺杆菌的患病率似乎随着胃部病变严重程度的增加而降低。总之，建议在适当评估临界值并验证后，将消化性溃疡疾病根除治疗后抗幽门螺杆菌（IgG）状态的非侵入性血清学评估扩展到CG和IM患者的随访。
