Xpert MTB／RIF在骨关节结核患者快速诊断中的应用

The Application of Xpert MTB/RIF Assay for Rapid Diagnosis of Osteoarticular Tuberculosis

目的探讨Xpert MTB／RIF在骨关节结核患者快速诊断中的应用价值。方法2014年2月-2014年11月使用Xpert MTB／RIF对49例骨关节结核患者及32例非结核性骨关节病患者的脓液标本进行检测，以临床诊断为金标准，计算Xpert MTB／RIF检测结核分枝杆菌的敏感性、特异性、阳性预测值、阴性预测值、一致率；同时对脓液标本行抗酸染色及结核分枝杆菌快速培养（BACTECT MGIT 960），比较Xpert MTB／RIF与抗酸染色、结核分枝杆菌快速培养在敏感性及特异性上的差异；综合上述两方面因素评价Xpert MTB／RIF在骨关节结核患者快速诊断中的应用价值。结果Xpert MTB／RIF检测单个脓液标本的时间为2-3±0．2h。49例骨关节结核患者脓液标本中，46例Xpert MTB／R．IF检测结核分枝杆菌阳性，3例Xpert MTB／RIF阴性；32例非结核性骨关节病患者脓液标本中，1例XpertMTB／RIF检测结核分枝杆菌阳性，31例Xpert MTB／RIF阴性；以临床诊断为金标准，Xpert MTB／RIF检测结核分枝杆菌的敏感性为93．87％、特异性为96．87％、阳性预测值为97．87％、阴性预测值为91．17％，一致率为95．06％。在46例Xpert MTB／RIF结核分枝杆菌阳性的骨关节结核患者中，10例存在利福平耐药突变基因，耐药突变率为21．73％。49例骨关节结核患者脓液标本中，抗酸染色阳性8例，阴性4l例，敏感性为17．39％；结核分枝杆菌快速培养阳性患者11例，阴性38例，敏感性为23．91％；32例非结核性骨关节病患者脓液标本抗酸染色及结核分枝杆菌快速培养均为阴性，其特异性均为100％。Xpert MTB／RIF检测结核分枝杆菌的的敏感性优于抗酸染色及结核分枝杆菌快速培养（P〈0．05），特异性与抗酸染色及结核分枝杆菌快速培养无明显差异（P〉0．05）。结论Xpert MTB／RIF在骨关节结核患者的快速诊断中具有较高的诊断效能，其耗时短，敏感性高，特异性强，与抗酸染色及结核分枝杆菌快速培养比较具有明显优势。

Objectives To investigate the role ofXpert MTB/RIF assay for rapid diagnosis ofosteoarticular tuberculosis. Methods From February 2014 to November 2014, pus specimens of 49 osteoarticular tuberculosis patients and 32 nontuberculosis patients were detected by Xpert MTB/RIF system, and the sensitivity, specificity, positive predictive value, negative predictive value, agreement rate of Xpert MTB/RIF system were calculated, and clinical diagnosis was used as the reference standard. All the pus specimens were detected by acid-fast stain and fast culturing（BACTECT MGIT 960）, to find the difference of sensitivity and specificity among Xpert MTB/RIF, acid-fast stain, and fast culturing. The role of Xpert MTB/RIF assay for rapid diagnosis of osteoarticular tuberculosis was evaluated through the two factors above. Results It took 2.3 ~ 0.2h to detect each pus specimen by Xpert MTB/RIF. Among the 49 osteoarticular disease patients, 46 were positive, 3 were negative by Xpert MTB/RIF test. Among the 32 nontuberculosis patients, 1 was positive, 31 were negative by Xpert MTB/RIF test. The sensitivity, specificity, positive predictive value, negative predictive value, agreement rate was 93.87%, 96.87%, 97.87%, 9 h 17%, 95.06% respectively for Xpert MTB/RIF assay. Among the 46 specimens which were positive by Xpert MTB/RIF test, 10 had rifampicin resistance mutation, with the rate of rifampicin resistance mutation as 21.73%. Among the 49 osteoarticular disease patients, 8 were positive, 41 were negative by acid-fast stain test, the sensitivity was 17.39%, and based on fast culturing test, 11 were positive, 38 were negative, the sensitivity was 23.91%. All pus specimens of 32 nontuberculosis patients were negative by acid-fast stain test and fast culturing test. As for the sensitivity, Xpert MTB/RIF was superior to acid-fast stain and fast cultureing （ P〈0.05 ） . While as for the specificity, there was no statistical difference among Xpert MTB/RIF, acid-fast stain, or fast culturing （ P〉0.05 ） . Conclusions The role of Xpert MTB/RIF assay for rapid diagnosis of osteoarticular tuberculosis is perfect. It is of time saving, high sensitivity and high specificity, which is superior to the traditional methods.