Kumar Ankur, Singh Amresh Kumar, Gaur Vivek, Mishra Ashwini Kumar, Mehta Anita, Singh Raj Kishore
Department of Microbiology, Baba Raghav Das Medical College, Gorakhpur, Uttar Pradesh, India.
Department of Respiratory Medicine, Baba Raghav Das Medical College, Gorakhpur, Uttar Pradesh, India.
Int J Mycobacteriol. 2025 Apr 1;14(2):110-116. doi: 10.4103/ijmy.ijmy_17_25. Epub 2025 Jun 20.
Tuberculosis (TB), caused by Mycobacterium tuberculosis complex, results in approximately 1.5 million annual deaths globally. Diagnosing extrapulmonary TB (EPTB) remains challenging due to the invasive nature of sample collection and limitations in conventional diagnostic sensitivity. This study evaluates the diagnostic performance of Xpert®Mycobacterium tuberculosis/Rifampicin (MTB/RIF), a nucleic acid amplification test, against direct microscopy for EPTB specimens. In addition, we compare the detection of first-line anti-tubercular drug resistance between Xpert® MTB/RIF and the MTB-DR plus line probe assay.
From January 2022, to April 2023, 2839 clinically suspected EPTB specimens were collected from patients referred to tertiary care hospitals in Gorakhpur, India. Specimens included lymph node aspirates, pleural fluid, cerebrospinal fluid, and tissue biopsies, processed according to the Indian National Tuberculosis Elimination Program protocols. Diagnostic evaluations employed microscopy (acid-fast bacilli staining), Xpert® MTB/RIF, and MTB-DR plus assays.
Of 2839 specimens, Xpert® MTB/RIF detected M. tuberculosis in 339 cases (11.9%), significantly outperforming microscopy (183 cases, 6.4%). The highest positivity rates occurred in tissue biopsies and lymph node aspirates (29%), while genitourinary TB was least frequent. Rifampicin resistance was identified in 14 cases (4.13%), all confirmed as multidrug-resistant TB (MDR-TB) by MTB-DR plus.
Xpert® MTB/RIF demonstrated superior sensitivity over microscopy, supporting its utility for EPTB diagnosis in low-resource settings. The high MDR-TB prevalence (4.13%) underscores the need for rapid molecular diagnostics to guide treatment. However, global EPTB burden estimates remain inconsistent, necessitating standardized surveillance and diagnostic protocols to improve detection accuracy and inform public health strategies.
由结核分枝杆菌复合群引起的结核病（TB）在全球每年导致约150万人死亡。由于样本采集具有侵入性以及传统诊断敏感性存在局限性，肺外结核病（EPTB）的诊断仍然具有挑战性。本研究评估了核酸扩增检测Xpert® 结核分枝杆菌/利福平（MTB/RIF）针对EPTB标本相对于直接显微镜检查的诊断性能。此外，我们比较了Xpert® MTB/RIF与MTB-DR plus线性探针检测法在一线抗结核药物耐药性检测方面的差异。
从2022年1月至2023年4月，从印度戈勒克布尔三级医院转诊的患者中收集了2839份临床疑似EPTB标本。标本包括淋巴结抽吸物、胸腔积液、脑脊液和组织活检样本，按照印度国家结核病消除计划方案进行处理。诊断评估采用显微镜检查（抗酸杆菌染色）、Xpert® MTB/RIF和MTB-DR plus检测法。
在2839份标本中，Xpert® MTB/RIF在339例（11.9%）中检测到结核分枝杆菌，显著优于显微镜检查（183例，6.4%）。组织活检和淋巴结抽吸物中的阳性率最高（29%），而泌尿生殖系统结核最为少见。在14例（4.13%）中鉴定出利福平耐药，所有这些病例通过MTB-DR plus均被确认为耐多药结核病（MDR-TB）。
Xpert® MTB/RIF显示出比显微镜检查更高的敏感性，支持其在资源匮乏地区用于EPTB诊断的效用。耐多药结核病的高患病率（4.13%）强调了需要快速分子诊断来指导治疗。然而，全球EPTB负担估计仍然不一致，需要标准化的监测和诊断方案以提高检测准确性并为公共卫生策略提供依据。
