Prakash A Keerthi, Ramakrishnan Gayathri Devi Anur
Department of Respiratory Medicine, Apollo Hospital, Chennai, Tamil Nadu, India.
Lung India. 2025 Jul 1;42(4):304-308. doi: 10.4103/lungindia.lungindia_144_25. Epub 2025 Jun 27.
Gene Xpert sensitivity is low in paucibacillary conditions like extrapulmonary tuberculosis (EPTB); to overcome that, Gene Xpert Ultra was introduced. This study aims to assess Gene Xpert Ultra's diagnostic accuracy in EPTB.
This prospective observational study was conducted at Apollo Hospital, Greams Road, Chennai, Tamil Nadu, India, from May 2022 to April 2023. A total of 200 patients, 39 (19.5%) abdominal, 61 (30.5%) musculoskeletal, one (0.5%) bone marrow, 50 (25%) lymph nodes, 11 (5.5%) CNS, two (1%) upper airway, one (0.5%) cardiovascular, and 35 (17.5%) pleural cases were enrolled. Samples were analyzed for Gene Xpert Ultra, MGIT culture, cytology, and histopathology wherever feasible with tuberculosis. Tissue sampling was performed rather than bodily fluid in all cases except in CNS and abscess, where CSF and pus were analyzed, respectively. Gene Xpert Ultra was then compared with MGIT culture and Composite reference standard (CRS).
The pooled sensitivity and specificity of Gene Xpert Ultra were 96.18% and 18.84% against MGIT and 94.30% and 100% against CRS. The lowest sensitivity (90%) was in CSF, and the highest (100%) was in pleura against CRS.
Gene Xpert Ultra has high sensitivity and specificity in tissue samples in various system involvements. This study recommends employing Gene Xpert Ultra in EPTB and further encourages tissue sample testing.
在肺外结核（EPTB）等菌量少的情况下，Gene Xpert检测的敏感性较低；为克服这一问题，推出了Gene Xpert Ultra。本研究旨在评估Gene Xpert Ultra在EPTB中的诊断准确性。
本前瞻性观察性研究于2022年5月至2023年4月在印度泰米尔纳德邦金奈格里姆斯路的阿波罗医院进行。共纳入200例患者，其中腹部39例（19.5%）、肌肉骨骼系统61例（30.5%）、骨髓1例（0.5%）、淋巴结50例（25%）、中枢神经系统11例（5.5%）、上呼吸道2例（1%）、心血管系统1例（0.5%）、胸膜35例（17.5%）。只要可行，对样本进行Gene Xpert Ultra、MGIT培养、细胞学和组织病理学检查以诊断结核病。除中枢神经系统和脓肿分别分析脑脊液和脓液外，所有病例均进行组织采样而非体液采样。然后将Gene Xpert Ultra与MGIT培养和综合参考标准（CRS）进行比较。
Gene Xpert Ultra针对MGIT的合并敏感性和特异性分别为96.18%和18.84%，针对CRS的合并敏感性和特异性分别为94.30%和100%。针对CRS，脑脊液中的敏感性最低（90%），胸膜中的敏感性最高（100%）。
Gene Xpert Ultra在各种系统受累的组织样本中具有高敏感性和特异性。本研究建议在EPTB中使用Gene Xpert Ultra，并进一步鼓励进行组织样本检测。
