Kumar Suraj, Bopanna Sawan, Kedia Saurabh, Mouli Pratap, Dhingra Rajan, Padhan Rajesh, Kohli Mikashmi, Chaubey Jigyasa, Sharma Rohini, Das Prasenjit, Dattagupta S, Makharia Govind, Sharma S K, Ahuja Vineet
Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India.
Department of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Intest Res. 2017 Apr;15(2):187-194. doi: 10.5217/ir.2017.15.2.187. Epub 2017 Apr 27.
BACKGROUND/AIMS: The use of genetic probes for the diagnosis of pulmonary tuberculosis (TB) has been well described. However, the role of these assays in the diagnosis of intestinal tuberculosis is unclear. We therefore assessed the diagnostic utility of the Xpert /rifampicin (MTB/RIF) assay, and estimated the prevalence of multidrug-resistant (MDR) TB in the Indian population.
Of 99 patients recruited, 37 had intestinal TB; two control groups comprised 43 with Crohn's disease (CD) and 19 with irritable bowel syndrome. Colonoscopy was performed before starting any therapy; mucosal biopsies were subjected to histopathology, acid-fast bacilli staining, Lowenstein-Jensen culture, and nucleic acid amplification testing using the Xpert MTB/RIF assay. Patients were followed up for 6 months to confirm the diagnosis and response to therapy. A composite reference standard was used for diagnosis of TB and assessment of the diagnostic utility of the Xpert MTB/RIF assay.
Of 37 intestinal TB patients, the Xpert MTB/RIF assay was positive in three of 37 (8.1%), but none had MDR-TB. The sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert MTB/RIF assay was 8.1%, 100%, 100%, and, 64.2%, respectively.
The Xpert MTB/RIF assay has low sensitivity but high specificity for intestinal TB, and may be helpful in endemic tuberculosis areas, when clinicians are faced with difficulty differentiating TB and CD. Based on the Xpert MTB/RIF assay, the prevalence of intestinal MDR-TB is low in the Indian population.
背景/目的：基因探针在肺结核（TB）诊断中的应用已有详细描述。然而，这些检测方法在肠结核诊断中的作用尚不清楚。因此，我们评估了Xpert/利福平（MTB/RIF）检测的诊断效用，并估计了印度人群中耐多药（MDR）结核病的患病率。
在招募的99例患者中，37例患有肠结核；两个对照组分别为43例克罗恩病（CD）患者和19例肠易激综合征患者。在开始任何治疗前进行结肠镜检查；对黏膜活检组织进行组织病理学检查、抗酸杆菌染色、罗氏培养，并使用Xpert MTB/RIF检测进行核酸扩增检测。对患者进行6个月的随访，以确认诊断和治疗反应。采用综合参考标准诊断结核病并评估Xpert MTB/RIF检测的诊断效用。
在37例肠结核患者中，Xpert MTB/RIF检测37例中有3例呈阳性（8.1%），但均无耐多药结核病。Xpert MTB/RIF检测的敏感性、特异性、阳性预测值和阴性预测值分别为8.1%、100%、100%和64.2%。
Xpert MTB/RIF检测对肠结核的敏感性低但特异性高，在地方结核病流行地区，当临床医生难以区分结核病和克罗恩病时可能有帮助。基于Xpert MTB/RIF检测，印度人群中肠耐多药结核病患病率较低。
