Mohanty Monalisa, Mishra Baijayantimala, Jain Mantu, Karaniveed Puthiyapura Lubaib
Department of Microbiology, AIIMS Bhubaneswar, Bhubaneswar 751019, Odisha, India.
Department of Orthopaedics, AIIMS Bhubaneswar, Bhubaneswar 751019, Odisha, India.
World J Orthop. 2022 Mar 18;13(3):289-296. doi: 10.5312/wjo.v13.i3.289.
Osteoarticular tuberculosis (OATB) is a severe form of extrapulmonary tuberculosis (TB), which causes notable morbidity and warrants a high index of suspicion for prompt management. The diagnosis of OATB poses a challenge, because of the difficulty of collecting the samples and, secondarily, the paucibacillary nature of lesion, which gives poor sensitivity and reproducibility, with long turnaround time of routine/conventional laboratory tests and the requirement for invasive procedures and expertise. The Xpert MTB/RIF assay has been approved by the World Health Organization as a rapid diagnostic tool for diagnosing pulmonary and extrapulmonary TB.
To emphasize the diagnostic efficiency of gene Xpert for OATB in suspected patients in a tertiary care hospital of Eastern India.
This retrospective study was conducted in the Department of Microbiology and Orthopaedics by analyzing the data of the gene Xpert assay over a 3-year duration from January 2018 to February 2021. Demographic and clinical data were recorded. The diagnostic efficiency of gene Xpert was evaluated against the composite reference standard (CRS).
A total of 37 cases fell into positive, probable, and possible categories of osteoarticular TB out of 112 patients included in the study by CRS; gene Xpert result was positive in 35 out of the 37 different CRS categorized cases. Of the 112 cases, culture was put in 40 cases, and, of these cultures, 5 cases showed the growth of MTB. Of these, 4 cases were included in the 35 cases diagnosed by gene Xpert. Smear microscopy was positive in 6 out of 37 CRS categorized cases. When compared with CRS, the sensitivity of gene Xpert assay, culture, and smear was found to be 94.6%, 13.5%, and 16.2%, respectively, while specificity in all the three types of tests was 100%. When kappa statistics were applied, the percentage of agreement gene Xpert, culture, and microscopy with CRS was found to be 95%, 20%, and 22.6%, respectively. Follow-up of the gene Xpert positive patients after getting anti-tubercular treatment revealed improved conditions.
Gene Xpert could detect 31 extra cases with a low and very low mycobacterial load that were missed by the routine culture methods. Hence, more samples should be processed for molecular diagnostic methods like gene Xpert along with other conventional methods for the validation of the molecular test prospectively for the timely diagnosis of osteoarticular TB.
骨关节结核（OATB）是肺外结核（TB）的一种严重形式，会导致明显的发病率，需要高度怀疑以进行及时治疗。OATB的诊断具有挑战性，这是因为样本采集困难，其次是病变的菌量少，导致敏感性和可重复性差，常规实验室检测周转时间长，且需要侵入性操作和专业知识。Xpert MTB/RIF检测已被世界卫生组织批准为诊断肺结核和肺外结核的快速诊断工具。
强调基因Xpert在印度东部一家三级医院疑似患者中对OATB的诊断效率。
本回顾性研究在微生物学和骨科进行，通过分析2018年1月至2021年2月3年期间基因Xpert检测的数据。记录人口统计学和临床数据。根据综合参考标准（CRS）评估基因Xpert的诊断效率。
在CRS纳入研究的112例患者中，共有37例属于骨关节结核的阳性、可能和疑似类别；在37例不同CRS分类的病例中，基因Xpert检测结果为阳性的有35例。在112例病例中，40例进行了培养，其中5例培养出结核分枝杆菌。其中，4例包含在基因Xpert诊断的35例病例中。涂片显微镜检查在37例CRS分类病例中有6例呈阳性。与CRS相比，基因Xpert检测、培养和涂片的敏感性分别为94.6%、13.5%和16.2%，而三种检测类型的特异性均为100%。应用kappa统计时，基因Xpert、培养和显微镜检查与CRS的一致性百分比分别为95%、20%和22.6%。对基因Xpert检测阳性的患者进行抗结核治疗后的随访显示病情有所改善。
基因Xpert可以检测出31例常规培养方法遗漏的结核分枝杆菌载量低和极低的额外病例。因此，除了其他传统方法外，应该对更多样本进行基因Xpert等分子诊断方法检测，以便前瞻性地验证分子检测，从而及时诊断骨关节结核。
