PCR法诊断幽门螺杆菌感染的评价

目的系统评估聚合酶链反应扩增尿素酶Ａ基因（ＰＣＲ法）对幽门螺杆菌（Ｈｐ）感染的诊断价值．方法采用金标准及ＰＣＲ法检测６９例患者（慢性胃炎５２例、消化性溃疡１２例、胃癌５例）胃粘膜内Ｈｐ．结果金标准诊断有Ｈｐ感染３４例，ＰＣＲ法诊断３５例Ｈｐ阳性；金标准诊断３５例无Ｈｐ感染，ＰＣＲ法诊断３４例Ｈｐ阴性．故ＰＣＲ法敏感度为１００％，特异度为９７１％，粗一致性为９８５％，调整一致性为９８６％，误诊率（假阳性率）为２９％，漏诊率（假阴性率）为０，正确诊断指数（ｒ）为１０，阳性预测值（＋ＰＶ）为９７１％，阴性预测值（ＰＶ）为１００％，阳性似然比（ＬＲ＋）为３５，阴性似然比（ＬＲ）为０．结论ＰＣＲ法对胃粘膜Ｈｐ感染的诊断价值高于细菌培养、组织病理学，尿素酶试验各单项方法．

Evaluation of PCR method in detection of Helicobacter pylori infection

AIM To evaluate serially the diagnostic value of polymerase chain reaction (PCR) amplificating urease A gene (PCR method) in detection of Helicobacter pylori (Hp) infection. METHODS By using gold standard and PCR method, Hp in gastric mucosa of 69 patients (chronic gastritis 52 cases, peptic ulcer 12 and gastric carcinoma 5) was detected. RESULTS By gold standard, Hp infection was detected in 34 patients, and by PCR method in 35 patients. Hp was negative by gold standard in 35 patients, and by PCR method in 34 patients. Therefore, the sensitivity and specificity of PCR method were 100% and 97 1% respectively. The rough and adjusted identity of PCR method was 98 6% and 98 6% respectively. The erroneous diagnostic rate (false positive rate) was 2 9% and missing diagnostic rate (false negative rate) was 0%. The right diagnostic index (r) was 1 0, and positive predictive value ( pv) was 97 1%, and negative predictive value (-pv) was 100%. Positive likelihood ratio (LR ) was 35 and negative likelihood ratio (LR -) was 0. CONCLUSION The diagnostic value of PCR method for Hp infection in gastric mucosa was higher than that of any other single method such as bacterial culture and histopathology and urease tests.